B. Hydroelectric Power Plant converts the inherent energy of water under pressure into electrical energy. The size, location and type of power plant depend upon the topography, the geological conditions and the amount of water and head (low, medium, or high) available. Its main elements are:

1. Principal Elements(a) Reservoir usually formed by building a dam across a river. Dams can be of two types: (1) impounding, or non-overflow, usually provided with a means to release excess flow, by a separate spillway action, by regulating gates, or by large spillway gates. Earth dams, rock-fill dams, and high-reservoir concrete-arch dams are examples of this type. (2) Spillway, or overflow dams are always concrete, and for low-head installations, the powerhouse usually forms part of the dam.(b) Intakes consists of canals, flumes, or concrete passageways to carry the water directly to low-head turbines or to the pressure conduits used for medium- and high-head turbines.(c) Pressure Conduits consists of concrete or rock tunnel, steel pipelines, steel penstocks or a combination thereof. They also connect the upper reservoir to the surge tank or penstock.(d) Surge Tank, to prevent excessive pressure rises and drops during sudden load changes, installed somewhere along the pressure conduit when the latter is quite long.(e) Trash Racks are provided at the inlet to the intake or the conduit to protect the turbine against floating or other material. Cleaning devices such as manual or motor-operated rakes are provided to remove debris from the racks.(f) Head Gates or Stop Logs, usually made of steel, are provided at the inlet to the intake or conduit and at the outlet of the draft tube for shutting off the flow to the turbine for safety and for ease of maintenance.(g) Penstocks are closed conduits connecting the upper reservoir, tunnel, or surge tank with the turbine casing. In medium-head installations, each turbine usually has its own penstock. In case of high heads, a single, branched, penstock is provided to supply two or more turbines.(h) Hydraulic Turbine consisting primarily of a runner, connected to a shaft, for producing prime motive power from the inherent energy of water under pressure. a mechanism for controlling the quantity of water flowing to the runner, and water passages leading to and away from the runner. Penstock valves, located at the intake of the turbine spiral case, are provided when the conduit is of considerable length, thus providing means of shutting off the flow for safety, maintenance and to reduce leakage during long turbine shutdowns. (i) Governor for operating the hydraulic turbine control mechanism.(j) Generator connected to the hydraulic-turbine shaft to convert the prime motive power of the turbine to electric power.(k) Pressure Regulator, sometimes used instead of a surge tank, to prevent excessive pressure rises and drops during sudden load changes in plants with long pressure conduits.(l) Draft Tube usually part of the powerhouse structure to carry water away from the turbine runner.(m) Tailrace used to carry water away from the draft tube to the tailrace reservoir.(n) Tailrace Reservoir receives the water discharged from the draft tube or tailrace and is usually part of the original river at an elevation lower than the upper reservoir.

2. Powerhouse Structure to enclose and support the hydraulic turbine, generator, governor, pressure regulator, water passages including draft tube, basements, passageways for access to the

turbine casing and draft tube and auxiliaries, including the foundation and the superstructure. Transformers and oil circuit breakers are located with the superstructure, on the roof or on a deck built over the draft-tube extension. The transformers and switchgear are usually located outdoors adjacent to the powerhouse and are not integral part of it. Cranes are provided in the powerhouse to handle the heaviest machinery pieces.

3. Powerhouse Auxiliaries include special apparatus consisting of:(a) Service Units a small hydraulic turbine and generator used for supplying power for internal plant use and as as source of independent power supply in case the power plant is electrically separated from the main system.(b) Casing drain valves for draining the turbines.(c) Strainers, or filters for bearing and cooling-water supply.(d) Air Compressors for charging governor oil systems, generator brakes, tail-water depression systems(e) Carbon Dioxide System for fire protection.(f) DC Service for emergency power supply.

Sections: Introduction | Turbines | Power Plant Design | Performance

Hydraulic Turbines

Waterwheels are generally grouped into (1) reaction, where the water enters the turbine with high potential energy in the form of pressure and a lesser amount of kinetic energy in the form of velocity, and (2) impulse, when the water enters the turbine with high kinetic energy and a relatively low value of potential energy.

Classification of Turbines(1) Reaction Turbines The water enters the guide case of the turbine with high potential energy and relatively low kinetic energy. The potential energy, which is a function of the pressure difference between the runner inlet and exit, causes the fluid to flow through the runner buckets. As the fluid flows over the curved surface of the runner buckets, the fluid velocity on one side of the bucket is higher than on the opposite side. This difference in velocity on the surfaces of the bucket causes a pressure differential across the bucket which exerts a force on the bucket. This force at its respective radius in the runner, the revolving part, then causes the runner to restore and impart mechanical energy to the turbine shaft.(1.1) Francis reaction turbine. Water enters the spiral case from intake passages or penstocks, passes through the stay ring, guided by the stationary stay-ring vanes, then through the movable wicket gates through the runner and into the draft tube, through which it flows into the tailrace or the tail-water reservoir. They are normally used for head ranging from 100 to 1500 ft (30.5 to 457m). Specific speeds (ns) vary from 15 to 100 (57 to 382)(1.2) Propeller Turbines, also of reaction type, the runner has has unshrouded blades (no crown or band). The blades, 3 to 10, are either fixed or adjustable. Usually used for heads from 10 ft (3.05 m) up to 120 ft (36.5 m) but heads up to 200 ft (61 m) are feasible. Specific speeds (ns) vary from 80 to 250 (305 to 954).

1.2a Fixed-Blade Propeller Turbines, the runner blades are in a permanent fixed position. The blade angle is usually set between 20 to 28, where maximum efficiency occurs.1.2b Adjustable-Blade Propeller Turbines The blade angle may vary from -10° minimum to 40° maximum. The blades maybe adjusted by hand, by electric motor through a train of gears or by oil-pressure-operated blades. The latter more commonly known as a Kaplan Turbine1.2c Diagonal-Flow Propeller Turbines in which the axis of the blades is at approximately 45° with the main shaft. The blades may either be fixed or adjustable. Some turbines are designed that the blades can be closed against one another to shut off the flow of water through the runner.1.2d Axial-Flow Propeller Turbines is characterized by the straight through water passageway from intake to discharge. The turbine shaft is either horizontal, vertical or inclined. More recently, horizontal axial-flow turbines have been installed to harness tidal power. There are four types under this classification. The rim type has the generator rotor mounted around the periphery of the turbine runner. The pit and bulb type locates the generator in series with the turbine runner at a submerged elevation. The bulb type has the generator enclosed in a streamline, watertight housing located in the water passageway on either the upstream or the downstream side of the runner. The tube type has the generator located outside of the water passages, where the shaft may be inclined, thereby raising the generator above tailwater elevation.

(2) Impulse Turbines consist of one or more free jets of water discharging into an aerated space and impinging on a set of buckets attached around the periphery of a disk. Generally, the buckets are bowl-shaped and have a central dividing wall, or splitter, extending radially outward from the shaft. The splitter divides the stream, and the bowl-shape portions of the bucket turn the water back, imparting the full effect of the jet to the runner. The free jet is formed by water passing through the nozzle pipe, the needle nozzle, and then through the nozzle tip. These turbines are used when the head is too high for Francis turbines, which is normally a head exceeding 1600 ft (500 m) or below this number where excessive erosion due to foreign materials in the water presents a problem. THe runaway speed for these turbines ranges from 160 to 190 percent of normal speed, depending upon the specific speed of the runner. THe higher the specific speed, the higher the runaway speed.

Sections: Introduction | Turbines | Power Plant Design | Performance

Power Plant Design

Plant Arrangement The setting or arrangement of hydraulic turbines in a power plant varies with the type of turbine, the head, and the type of dam and intake.

Head range, ft Type of Turbine General Arrangement

Up to 120 Fixed-blade

propeller

Vertical with concretesemispiral or plate-steel

spiral case.

Up to 200 Conventionaladjustable-blade

Vertical with concretesemispiral or plate-steel

propeller or Deriaz. spiral case.

Up to 90 Pit, bulb, or tube Horizontal or inclined,

concrete and/orplate-steel intake.

100 to 1500 Francis Vertical or horizontal

plate-steelspiral case.

1000 to 5800 Impulse Vertical or horizontal

plate-steelspiral case.

Plant Design Factors A. Specific Speed, ns, is the relationship between the speed of the runner at the point of the highest efficiency and the maximum power output at this speed. Since both power and speed vary with head, specific speed is also the relationship between speed n1and speed P1at 1 ft (m) head. Subscript 1 denotes that the value is reduced by the similarity law to a 1-ft (m) head basis. Thus, specific speed is equal to:

n (P) / H5/4

where n, is the best efficiency speed; P, is the maximum power output at this speed; and H, the runner head where n and P operates. Impulse turbines' specific speed, ns, can be improved by increasing the number of jets used on a single runner or by increasing the number of runners per unit.

B. Speed Hydraulic turbines are usually connected to ac generators. THe turbine speed must agree with one of the synchronous speeds required for the system frequency. Synchronous speeds are determined by the formula n = 120 × frequency / number of poles in a generator. The number of poles should be even. The speed should be as high as practicable, since the higher the speed the less expensive will be the turbine and generator and the more efficient will be the generator.

C. Number of Units should be kept to a minimum, thus reducing the number of auxiliaries and the amount of associated equipment and also reducing initial and maintenance costs for the entire plant. The larger the unit, the higher the efficiency and generally the lower the cost per unit output. However, other considerations, such as flexibility of operation, higher efficiency operation during low-load demands, and minimum loss of capacity during shutdown for repair and maintenance, might dictate the use of multiple units.

D. Weight of Runner The approximate weight of any Francis runner is 0.030D³, where D is the diameter of the runner in inches at the centerline of the distributor. For fixed-type propeller runner, the weight is taken to be 0.009D³, and for Kaplan-type runners as 0.014D³.

E. Turbine Thrust The hydraulic thrust on Francis runners varies with type, design, specific speed, the pressure between the movable wicket gates and runner, seal design and clearance, and the method of venting. It is approximately between 25 and 45% of the weight of the full head of water acting on the discharge diameter, Dd, of the runner. The higher the specific speed, the greater is the thrust. With propeller-type runners, the thrust is nearly equal to the weight of water on the full area. Impulse turbines have no hydraulic thrust of any consequence.

F. WR² of turbine runners, which is their weight times the square of the radius of gyration, varies widely with the type of runner and its design, thus it must be calculated for each specific design, based upon its configuration and distribution of weight.

G. Runaway Speed is the value of overspeed if the turbine runner is allowed to revolve freely without load and with the wicket gates wide open. The runaway speed, at normal head, varies with the specific speed and for Francis turbines ranges from 170% (normal speed = 100%) at low specific speed [ns= 20 (76)] to approximately 195% at high specific speed [ns= 100 (381)]. For propeller turbines, the runaway speed varies with blade angle -- the steeper the blade angle, the lower the runaway speed. For fixed-blade set at 16 to 28º, where maximum efficiency is usually obtained, the runaway speed ranges from 225 to 180%, respectively. For adjustable-blade, where the minimum blade angle at 6 to 16º, to obtain efficiency at part load, the maximum possible runaway speed is about 290 to 270%, respectively. For all turbines, if the maximum head is higher than the normal head, the runaway speed will be increased in proportion to the square root of the head. Therefore, runaway speeds should be based on the maximum operating head rather than the normal head. Any runaway speed above 180% increases the cost of the generator.

Sections: Introduction | Turbines | Power Plant Design | Performance

Hydraulic Performance

Hydraulic Performance. Hydraulic turbines derive power from the pressure or force exerted by water falling through a given distance (the head).

Turbine Characteristics The theoretical power usually expressed in horsepower, Pt = HQw / 550 = HQ / 8.82, where H = the head in feet, Q = flow of water in cubic feet per second, and w = weight of water in pounds per cubic foot. The head is established by the topography of the country and the location of the dam, intake works, powerhouse, and tailrace or tailwater reservoir. An analysis of the river-flow records, type of turbine, and type of load (whether base or peak) will fix the maximum and mean value of flow to be used in the design. The actual horsepower P = Pt × h, where h is the turbine efficiency. For general purposes, a mean efficiency of 90% is assumed. Generator efficiency hgranges from 94 to 98%, The combined efficiency of both turbine and generator is about 85 to 93%.

Proportionality Laws The law of proportionality (the variation of power, speed, and discharge with runner size and head) for turbines of varying size, but with same basic dimensional relationship in water passageway design (also called homologous turbines) are shown below:

For ConstantRunner Diameter

For Constant Head For Variable diameter

and head

P µ H3/2 P µ D² P µ H3/2D²

n µ H1/2 n µ 1/D n µ H1/2/D

Q µ H1/2 Q µ D² Q µ H1/2/D²

where D is the nominal diameter of the turbine runner.

Efficiency of the head contemplated, will affect the maximum efficiency obtainable, as well as the percentage of full load where this maximum occurs and the efficiencies of part loads. As the specific speed increases, the percentage of full load at which the maximum efficiency occurs increases and part-load efficiencies drop.

Cavitation occurs when the pressure at any point in the flowing water drops below the vapor pressure of water. The relationship which produces cavitation is between vapor pressure, barometric pressure, setting of the runner with respect to tailwater, and net effective head on the turbine and is expressed by the Thoma cavitation coefficient, s = (Hb- Hv- Hs)/ H, where Hb= barometric head, ft (m) of water; Hv= vapor pressure of water, abs; Hs= elevation, ft (m) of the runner above tailwater, measured at the centerline of the distributor of a Francis turbine and at the centerline of the blades of a propeller runner (if the runner is submerged, this quantity becomes negative); and H = total of net effective head, ft (m), on the turbine. In absence of cavitation test, the value of s should not be lower than ns

3/2/ 2000 or (ns3/2/ 15,000) for Francis and

propeller runners and ns² / 25,000 or (ns² / 350,000 ) for adjustable blade propeller. The value of s at which a plant operates, depends upon the setting of the runner with respect to tailwater, is called the plant s. To avoid excessive cavitation, the plant s should exceed the critical s. The greater this margin, the less possibility of cavitation during operation.

Speed Regulation is accomplished by changing the flow of water to the turbine. The flow is controlled by the wicket gates of reaction turbines and by the needle vale or jet deflector of impulse turbines. The turbine governor moves the gates or needle in response to speed changes resulting from load or head changes.

1. Author. TitleBook Title Publisher, Place, Year, page.

 

Small HydroPower Handbook

        

A Guide to Understanding

and Constructing   Your Own Small

Hydro Project       

Indroduction

CHAPTER #1 -ENERGY FROM WATER - IS YOUR PROJECT WORTH PERSUING?

CHAPTER #2 - SITE EXPLORATION AND STREAMFLOW DATA

CHAPTER #3 - ASSESSMENT OF THE FEASABILITY OF YOUR HYDRO SITE

CHAPTER #4 - CIVIL WORKS AND EQUIPMENT

CHAPTER #5 - PERMITS, LICENSES AND LEGAL ASPECTS FOR SMALL HYDRO

CHAPTER #6 - ECONOMICS AND FINANCING

CHAPTER #7 - GETTING STARTED

CHAPTER #8 - LOW HEAD CONSIDERATIONS

CHAPTER #9 - COLD WEATHER CONSIDERATIONS

CHAPTER #10 - ORGANIZATION AND OPERATION OF A PUBLIC UTILITY

GLOSSARY

INTRODUCTION (Chapter 1 Index)

Why Small Hydro

British Columbia offers enormous small hydro potential to its inhabitants: about 2400 MW, with 550 sites near the grid. Small Hydro is part of the history of British Columbia. Many early mills, mines and towns built some form of power generation from small hydro, in the late 19th and early 20th centuries; and waterwheels were used much earlier - in Ashcroft, in 1863, for example. Most of these old sites have fallen into disuse by now - rendered uneconomic in the 1950's by the availability of

cheaper electricity through an expanding, province-wide grid; and by the availability of portable, flexible, low cost diesel generators. Diesel generators are still cheap to buy - but the rise in the cost of oil has made them expensive to operate. And the provinces electrical grid, while extensive, does not include a number of small communities, resource-based businesses, farmers, and lodge owners: people in out of the way locations who are paying an enormous cost for their independent way of life. Such people are taking another look at water power, because it offers a stable, inflation-proof source of electricity, using proven technology. Small hydro installations have, historically, been cheap to run but expensive to build. That is changing now, with smaller, lighter, and higher speed turbine equipment, lower cost electronic speed and load control systems, and inexpensive plastic piping. Capital investments are still higher than investing in diesel equipment of comparable capacity; but the long life and low operating costs of small hydro make it an attractive investment for many applications. Examples of such installations, built in B.C. during the past few years, include: Glacier Park (150 kW); Hoeya Hilton (37 kW); Nimmo Bay (40 kW); Hasty Creek (37 kW); Klemtu (650 kW); Kingcome (75 kW); and Rendell Creek Ranch. Some very small, and very successful units have been installed by entrepreneurs - a farmer in the Pemberton Valley, for example (25 kW). other, larger units, have been build by entrepreneurs who then sell power on contract to a resource industry - Lancaster Resources (now Synex) at Moses Inlet, selling to Crown Lumber. There are business opportunities in small hydro - and a number of people are catching on.

Purpose of the Manual

This book is written to assist people who are interested in developing a small hydro opportunity. It will be especially useful to people with small sites that would not justify the expense of extensive professional engineering services. Even with small sites, such services may be advisable if you have conditions you do not fully understand. The book will provide you with the information you need to: - evaluate the potential of a small hydro site; - lay out the site; - apply for necessary licences and permits; - get financing; - select and install equipment and - understand the equipment, so that you can operate and maintain the system yourself. The emphasis in the book is on doing as much as possible yourself, thus keeping capital costs as low as possible. However, advice on seeking professional help is also included - and the information contained in these chapters will be invaluable to you in dealing with any consultants and contractors you hire. Actual construction details are not included; general guidelines are given, along with pointers on what help can be expected from a construction contractor. The book does not assume any previous acquaintance with the subject. mathematical procedures are generally limited to multiplication and division for the fundamentals. (more sophisticated procedures may yield greater accuracy, but the simpler procedures outlined here should be sufficient for the scope of projects intended.) A hydro turbine generator can by very small, like the alternator for a car (c. 500 Watts); or it can be very large, like the units at the Revelstoke Dam (several thousands of millions of Watts). microhydro (1-100 kW) and mini-hydro

plants (100 kW to 5 MW) are the smallest of the turbine generator units. This handbook is aimed mainly at installations of less than 500 kW, although it covers licensing requirements up to 20 mw. The writers of the chapters that follow are all experts in their fields, and have all written as clearly and simply as possible. It will take time and study, however, to thoroughly understand each section of the book especially the charts, tables, and graphs. The effort will pay off: your chances of bringing a project to a successful completion, producing reliable energy year after year, and significantly improving your cash flow, will be greatly enhanced.

Cost of Development

Costs for smally hydro installations vary considerably, because sites, conditions and sizes are all different. In 1985, the typical development can range from $1,500 to $5,000 per installed kW. This would mean an investment of from $6,000 to $20,000 for the "typical" simple family home, which requires a peak demand of 5 kW. (If that home were using electric heating, the demand would be from 12-20 kW.) This handbook shows how to estimate installation cost, and how to balance design tradeoffs, cost, and projected energy production. You can significantly reduce costs by clever management, procurement, and hard work. The system at Rendell Creek Ranch cost only $25,000 for a 150 kW system - less than $200 per kW - because the community did most of the work itself and was able to buy and rebuild used equipment. In approaching costs, remember that there are two basic types of developers: those who are interested in generating to meet only their own needs, regardless of the site's potential; and those who want to get as much as possible out of the site. Costs for the former developer will generally be lower because the system will be smaller, and geared both to minimum requirements and minimum flow. Investment for the latter will be higher, but the per kW cost may be less.

Organization of the Manual

You are encouraged to peruse the book and gain a general knowledge of its contents before starting actual development. Chapters One, Two and Three represent the major steps for any site development. Chapter Four then treats dams, intakes, penstock, turbines and all equipment associated with the manufacture of a small hydro site, in considerable detail. Chapter Five serves as a guide to developers on the legal aspects of permits, licences and insurance. This is a weighty section, but an understanding of the requirements is essential. Chapter Six, on Economics and Financing, takes you through the economic feasibility of the project and helps you decide on the economics of the project. Chapter Seven is subtitled "Getting Started". It gives the developer some practical tips on the many logistical steps necessary to carry through with the project, once it is designed. It will help get the project started and help you make sure it is completed. Chapters Eight and Nine are specialized chapters on Low Head and Cold Weather Considerations. If you are working under either of these constraints, these chapters should be read carefully. Chapter 10

outlines the requirements for setting up a utility, should you wish to sell your surplus power.

CHAPTER #1 - ENERGY FROM WATER - IS YOUR PROJECT WORTH PERSUING?

1.1 ..........Introduction

1.2 ..........Your Power Requirements

1.3 ..........Power and Energy Definitions

1.4 ..........Data Collection

1.5 ..........Installations

1.6 ..........Available Power and Energy

1.7 ..........Advisors

1.8 ..........Project Costs

1.9 ..........Project Worth

1.10 ..........Continued Planning

1.11 ..........Project Data Summary

 

SUPPLEMENT / MEASURING HEAD AND STREAMFLOW / PRELIMINARY

1.1 ..........Introduction (Back)

Perhaps you are living close to a stream and you are considering building a small hydro project on it. Or perhaps you are starting to plan a project and you are looking for a suitable stream. In either case this chapter will help you. Chapter One covers: (a) The fundamentals of providing electrical energy from water; (b) the process of selecting a suitable stream and a site for a hydro project; (c) the simple calculations for helping you to decide whether you should continue planning your project, or whether you should start looking for some other way of getting electricity; and (d) the costs, procedures and time requirements of hiring an engineer to do the preliminary work. Probably your most valuable experience is to have lived next to a stream for several years and to have noted the fluctuations in its flow: how high and low it can

go, how soon it reacts to a rainstorm, and how the stream changes its course when in flood. However, without this background knowledge you will still be able to build a good hydro project. To help you decide whether or not to continue with your the project, you will be asked to (a) estimate the power you need; (b) estimate the streamflow available; (c) measure or estimate the head available on the stream; (d) estimate the power and energy available from the stream; (e) make a preliminary layout of your project; (f) make a preliminary estimate of the cost of your project; and (g) decide: "Is your project worth pursuing?" Each time you make an estimate or calculation, you should enter it in Table 1.3, "Project Data Summary" at the end of this chapter. If you have already decided to continue planning, you should still skim through this Chapter and check that you have the data listed under all the headings in Table 1.3.

1.2 ..........Your Power Requirements (Back)

First, you need to estimate how much power and energy you use at present, and how much you will use, say, ten years from now. Normally some degree of load management is used in mini-hydro plants. The loads shown in Table 1.1 assume some degree of load management.

1.2.2 Load Estimates

An approximate estimate of the load will do at this stage. A more accurate estimate will be made in Chapter 3. Using Table 1.1 to estimate your peak winter and summer loads, select a value within the ranges given. These ranges indicate the difference in loads due to different living styles and different climates. Take account of the appliances you have, compared to those listed in the table, and the conservation or extravagance in your use of electricity. Also consider the climate where you live: you will use more electricity in the interior and northern parts of B.C. than you will on the coast, on Vancouver Island, or in the Lower Mainland. Following the example below, write down your expected future peak load value for the winter (November-April) and summer (July-October). Use a future of 10 years time or whatever time span you wish to consider for the hydro plant. If you want to make a more detailed estimate, turn to the section on "Power and Energy Requirements" in Chapter 3. Do this only if you want to learn more about load management: it gets quite complicated. Example: A single family house with 2 bedrooms and workshop - electric lights, washer, drier, fridge, freezer, kitchen appliances (no oil, propane or wood cooking stove), baseboard and hot water heating, table saw, small hand tools. From Table 1.1: (In this example case 3B, a 3 bedroom house without back-up for heating, is used to allow for additions in the future.) Example Your Expected Loads Winter Maximum Load 12 kW ................ kW Summer Maximum Load 5 kW ................ kW (Write these values at the top of Table 1.3)

1.2.3 Energy Conservation

Do you conserve energy as much as you can? Have you considered the following ways of reducing your energy consumption, and thereby reducing your costs? - upgrading insulation in basements, floors, walls, cedilings and attic; - adding storm windows or double or triple glazing; - reducing air leaks by caulking and weatherstripping round dorrs and windows; - servicing the oil or propane furnace and water heater; - insulating the hot water tank and pipes;

1.3 ..........Power and Energy Definitions (Back)

The methods for calculating power and energy that are available from a stream are covered in this section.

1.3.1 ..........Power

The calculation of the actual power from your stream is covered in Section 1.6, after you have measured or estimated the flow and head. The theoretical power equation (Equation 1-1) is P= Q x H x e x 9.81 Kilowatts (kW) (1-1) Where: P = Power at the generator terminal, in kilowatts (kW). Q = Flow in pipeline, in cubic metres per second (m3/s). H = The gross head from the pipeline intake to the tailwater, in metres (m) (see Figure 1.2). e = The efficiency of the plant, considering head loss in the pipeline and the efficiency of the turbine and generator, expressed by a decimal (ie 85% efficiency 0.85) 9.81 = Constant for converting flow and head to kilowatts. All power systems produce less power than is theoretically available. The losses in a hydro plant are: (a) losses in energy caused by flow disturbances at the intake to the pipeline, friction in the pipeline, and further flow disturbances at valves and bends; and (b) losses of power caused by friction and design inefficiencies in the turbine and generator. The energy losses in the pipeline and at valves and bends, are called head losses: they represent the difference between the gross head and the net head that is available at the turbine (see Figure 1.2). The head losses in the pipeline could range from 5 percent to 15 percent of the gross head, . depending on the length of the pipeline and the velocity of the flow. The maximum turbine efficiency could range from 80 percent to 90 percent depending on the type of turbine, and the generator efficiency will be about 90 percent. At this stage in the planning of your hydro plant, the head losses can be combined with the losses in the tubine and generator, and an overall plant efficiency of 60 percent (or e = 0.60) can be used. Using e = 0.60 in Equation 1-1, the actual power output at the generator can be calculated from the following Equation 1-2: P x H x 5.9 (kW) (1-2) The Power Output Nomograph in Figure 1.3 enables you to make quick estimates of power, flow or head. Example: Suppose you know the lowest flow (discharge) in the stream (say 0.1 M3/s or 100 L/s), and you know where to put the intake and powerhouse so you can estimate the head (say 10 m). Example Your Values Flow 100 L/s L/s Head 10 m M In Figure 1.3 mark a point (in pencil) at a flow of 100 L/s on the DISCHARGE (left) scale; on the HEAD

(right) scale mark a point at a head of 10 m. Draw a straight line between the two points and where this line intersects the POWER (middle) scale is the estimated power, in this case 5.9 kW. Power 5:9 kw' kW If you have been using your own values of flow and head, and find that the power output is not enough for your power requirements, don't worry: you're just trying out the nomograph. Later in this chapter you will make the proper calculations. Other ways of using the nomograph are: (a) to find the necessary flow, provided you know your power requirements and can estimate the head available on the stream. Extend a straight line from the HEAD scale through the POWER output scale and onto the DISCHARGE scale, or, (b) to find the necessary head, provided you know your power requirements and can estimate the minimum flow in the stream. 1-6 1.3.2 Energy The equation to calculate energy is E = P x time Where: E = Energy, in kilowatt - hours (kW.h) P = Power, in kilowatts kW Time = Time while power is generated or used Example: If you run a 1000 watt (1 kW) electric heater for 5 hours you use 5 kW.h of energy.

1.4 ..........Data Collection (Back)

Streamflow, head and pipeline length must be estimated or measured, before you can calculate the power that could be developed from a stream. Streamflow is the most difficult to measure or estimate. However you should have an understanding of its sources, its fluctuations and flow measurements or estimates.

1.4.1 Streamflow

Streamflow comes from either rain or melting snow, but not all the rain or melting snow immediately becomes streamflow. There are losses caused by evaporation from the ground surface, transpiration by the vegetation whose roots have absorbed moisture from the ground and from seepage or surface water into the ground to become groundwater. This groundwater can take weeks or months to appear as streamflow, and is therefore not available for power immediately after rain or snowmelt. However, this groundwater is important, the major component of the streamflow during dry periods in the summer or winter. A hydro project should be designed for these dry, low flow periods. It is advised that you check both Fisheries and Water Licenses statutes of the creek prior to doing much work, it might belong to someone else.

Streamflow Fluctuations

We all know that streamflow fluctuates, often daily, always seasonally and yearly. To visualise these fluctuations, values of flow are plotted against time, as shown on Figure 1.4 (A and B) these plots are called hydrographs. In Figures 1.4.A and 1.4B, hydrographs of flows in 1980 are shown for six rivers in five different parts of B.C. Notice the different patterns of flow in different parts of the province. The simplest pattern is for Beatton Creek in southeast Interior (Figure 1.4A): (a) low flows in

January to March (cold weather). (b) rapidly increasing flows in April (snowmelt). (c) high, erratic flows in May and June (snowmelt plus rain). steadily decreasing flows in July and August (no further snowmelt). (d) low flows again through the winter. Brouse Creek (Figure 1.4A), in the same area as Beatton Creek, is much smaller. The pattern for these two creeks is similar except that in Brouse Creek the major snowmelt period is in May only. Moving westward to the Coquihala River (Figure 1.4A), the effect of winter rain is reflected in the extremely sharp peaks in December. A pronounced snowmelt period lasted from April until June, and prolonged low flow periods occurred in January and February and again between August and October. In the North, the Cottonwood River hydrograph (Figure 1.4B) shows the prolonged low flows caused by low temperatures from December through to the end of April. West of the Coast Mountains, the Little Wedeene River hydrograph (Figure 1.4B) shows the effect of heavy rain from September to December. The snowmelt period, April to June is not so obvious because of the erratic rain peaks superimposed. Short periods of low flows occurred in most months January - March and August - October. In the Northern part of Vancouver Island, the pattern of flows for the Ucona River is less distinct; erratic flows during the winter (rain and snowmelt), fairly steady flows April - June (snowmelt), then decreasing flows to September (little rain). Knowing these patterns will help you choose the right time of year to measure low flows and average flows. You will also recognize the relation between low, average and high flows; this will enable you to check the magnitude of your measurements or estimates.

Streamflow Measurements and Estimates While many larger streams and rivers in B.C. have gauges installed by Federal or Provincial Government agencies, it is unlikely that there will be a gauge on your stream. You will probably have to measure or estimate the flow. There are several ways to measure flow: 1-8 (a) use a float to measure velocity and a level and tape to measure the stream cross-section, (b) construct a weir (A weir is a low dam over which the water flows) across the stream and measure water levels or, (c) use a flow-meter to measure velocity, and a level and tape to measure the stream cross-section. using a float is the easiest but the least accurate method. Building a weir or using a flow-meter are the best methods for establishing a semi-permanent measuring station to obtain flows for several months or years. At this stage in the planning process, you should use the float method described in Supplement 1 . 1 (at end of this chapter). What flows should be measured? This will depend on the amount of water the hydro plant will take from the stream compared to the minimum flow in the stream. You need to get an overall picture of the variations in the flow of the stream. But the lowest flow is usually the most important because it can limit the maximum power that can be produced. At this stage, you don't know how much flow the hydro plant will take. But it is helpful, when deciding what stream flow to measure, to keep in mind three situations: 1. The stream is large and only a small portion of the lowest f low is needed for your hydro plant. If you know that you will always have enough water for the plant. You don't have to measure the flow; you can go onto the next section on "Head", however, if in doubt at all measure the flow. Streamflow is difficult to eyeball. 2. The minimum flow in the stream is about equal to or is slightly more than the flow needed to produce

maximum power. You should measure the lowest flow, then estimate the minimum flow that can be expected in the stream: this is explained later. 3. The minimum flow in the stream is less than the flow needed to produce maximum power, and water will have to be stored for part of the year (water storage is discussed in Section 1.6.3), or a diesel generator will have to be used when the flow is low. In this case, you need to know the low and average flows. You should measure the lowest flow you can and also the average flow, several times. If the stream dries in the summer or winter, measure the lowest flow about one month before it normally dries. Measure the flow when it is low and/or average, according to the three guidelines above. Make several measurements on different days.

1.5........ INSTALLATIONS (Back)

This is the time to decide on a preliminary arrangement for your hydro project: The locations of the intake, dam, pipeline and powerhouse: and the type of turbine needed. If possible, get a map of the area from a government office, a local logging company or a forester with the Ministry of Forests maps, and where to get them are discussed in Supplement 2.1 at the end of Chapter 3). Draw on the map the intake, dam, pipeline, powerhouse, and transmission line. This will help you define the layout and help you describe the project to someone else, such as a small hydro owner, a bank manager, a person in the Water Rights Branch office:

To help you decide on a layout, the following considerations will be covered in this section:

(a) run-of-river versus storage projects;

(b) typical project layouts;

(c) project structures ie. dam, weir, intake, canal, pipeline, powerhouse, tailrace,-

(d) to suitable turbines (Cross-flow, Francis and Pelton turbines) for love, medium and high head projects;

(e) existing dams and;

(f) transmission lines.

1.5.1 Run-of-River versus Storage Projects

A run-of-river project is built to use some or most of the flow in a stream depending upon the flow throughout the year. No attempt is made to store water for the dry periods. A run-of-river project would not normally have a dam, other than an intake weir, which is a very low structure at the intake. The intake weir keeps the water in

the stream high enough to fill the pipe at all times.

A storage project on the other hand, has a dam, which creates a water storage reservoir to maintain flow in the stream during low flow periods. The intake to the pipeline might be part of the dam or separate from it, depending on the location of the pipeline.

1.5.2 Project Layouts

The layouts shown in Figure 1.5 are typical of most projects that would be built in B.C.

Layout #1 is the simplest, with a weir or low dam across the stream, an intake to the pipeline, the pipeline, powerhouse and tailrace channel (each structure is described in more detail in Section 1.5.3). The weir forms a pond to ensure that there is always water above the pipe at the intake; the pipeline carries the water, under pressure, to the turbine in the powerhouse; the tailrace channel carries the water from the turbine back into the stream, or into a lake or the sea.

Layout #2 illustrates a possible cost-saving arrangement, whereby a canal or low-pressure pipeline is built to contour around a hillside, and a shorter high-pressure pipeline, called a penstock, is used.

Layout #3 shows a pipeline intake incorporated in a storage dam.

Layout #4 shows a situation where there is a lake suitable for a storage reservoir some way up the stream. A dam can be built at the lake to store water, which can be released down the stream during dry periods.

Layout #5 and Layout #6 show the layout of a low head plant where there is less than 10 m gross head. Notice that there is no pipeline or dam. Layout #5 shows the weir, intake and powerhouse combined into one structure. Layout #6 shows a power canal between the intake and powerhouse.

Many aspects of a low head plant are different from those of a higher head plant (head greater than 20 m): flows are higher, the turbine is larger, no pipeline is used. For these reasons low head plants are discussed separately in Chapter 8.

1.5.3 Structures

The structures of a hydro project are described in detail in this section. Guidelines for selecting sites for these structures are given in Chapter 2, Section 2.6. Suggestions are given below for estimating dimensions for some of the structures. This will enable you,

in Section 1.8.1, to estimate the cost of your project.

Storage Dam

A storage dam, normally 3 m to 10 m high and constructed of earth or rock, should be designed by an engineer.

There are many different designs for earth and rock dams. A typical earth-fill dam, as shown in Figure 1.6, has a central section constructed of low permeable material supported on either side by higher permeable material. The material has to be carefully compacted in thin layers as it is built.

The pipe through the dam could continue to the turbine, or could discharge into the stream or a canal at the downstream side of the dam. There would be a valve at the upstream end of the pipe.

A spillway would be built into the dam to allow high flows to pass without overtopping the dam. The crest of the spillway would be lower than the top of the dam.

Intake Weir

Normally you would need to build a low weir (1 m to 2 m high) across the stream at the intake to the pipeline, to form a headpond (see Figure 1.6). This headpond would:

(a) ensure a high enough water level to keep water always above the top of the pipe.

(b) allow some of the sediment in the stream to settle out before entering the sediment trap,

(c) allow an ice sheet to form, giving some protection against water freezing in the pipeline, and

(d) provide pondage (water storage) to compensate for one or two-day water shortages.

Water would flow over the weir most of the time.

While there are many ways to build a weir, concrete, rock-filled gabion and rockfilled timber-crib structures are the most common for small hydro projects (see Figure 1.6).

If the weir is built across a narrow part of the stream and founded on bedrock, a concrete structure would probably be the most economical. In other cases a concrete structure would probably be the most expensive, but it would also last the longest

without maintenance.

A gabion is a wire-mesh box filled with rock. Assuming there is a good supply of rock at the site, only the wire-mesh need be bought and transported to the site. Gabions are not waterproof, so an impervious polyethylene membrane or asphalt sheeting would be laid on the upstream side. Fill would be placed on the upstream side to protect the membrane. A reinforced concrete cap should be placed on the top of the gabions to protect them from the water and debris passing over the weir.

A rock-filled timber-crib dam is often the least costly weir to build, especially if rock is,available at the site and timber can be cut nearby.- Timber or logs are placed in alternate directions and spiked where they cross (see Figure 1.6). The bottom logs should be anchored to the foundations, and the space between the logs should be filled with rock. Wooden sheathing is attached to the upstream face and the crest, and often sheathing is also placed on the downstream face. Low permeability fill should be placed upstream to reduce seepage through the dam and foundations.

Water in the headpond must be kept at a certain height (called submergence) above the top of the pipe, to prevent air entering the pipe. Values of submergence are given below:

Pipe Diameter Submergence

less than 600 mm = 1.0 m

600 - 1200 mm  = 1.5 m

(Pipe diameter is discussed in detail in the "Pipeline" section, which follows.)

The crest of the weir should be above the top of the pipe by an amount equal to 0.5 m plus submergence.

Intake

The intake to the pipeline can be a separate structure, part of the intake weir, or part of the storage dam. There are many types of intake. The sketch in Figure 1.6 shows the components of a typical intake.

To prevent sediment from flowing into the turbine, a sediment trap can be built upstream of the intake structure or within the structure; or immediately downstream, as a separate self-flushing tank built into the pipe.

A trashrack prevents floating debris from entering the pipe. Trashracks must be

cleaned regularly.

Stop-logs or a valve should be provided to shut off the flow from the pipeline during maintenance or repair of the pipe, or closure of the turbine during cold weather. An air vent should be placed just downstream of the valve to prevent the pipeline collapsing when it is emptied with the valve closed.

The top of the intake should be at least 0.5 m below the top of the weir.

Pipeline

To help you determine the preliminary arrangement and cost estimate of your project, you also need to decide on pipe diameter, pipe material, above-ground or underground pipe location, pipe support and anchore blocks.

You need to know the diameter of the pipeline to estimate its cost in Section 1.8.1. The diameter can be read from the graph in Figure 1.7, by using your value of Qmin (from Section 1.4.1, or from Table 1.3) on the horizontal axis, then reading the diameter on the vertical axis.

Example: Your Values

pipe flow =Qmin.....................................200 L/s ...................................L/s

or 0.20 m3/s ....................................M3/s

Pipe Diameter D................................... 410 mm .........................mm

Write your value of pipe diameter in Table 1.3 for later reference.

Steel, cast iron, aluminum, polyethylene and PVC are materials used for small hydro pipelines and penstocks. Generally, for the higher head sites in B.C. (above 20 m head) polyethylene or PVC are used. When the head is greater than about 60 m, use of steel at the lower end (higher head) of the pipeline is more economical.

PVC pipe should be buried for protection from the sun's ultraviolet rays and polyethylene and cast iron pipes should be buried for potection against damage from falling trees or rocks, or from logging machinery. If air temperatures normally stay below -5C for more than five days at a time, the pipeline should be buried or insulated.

Supports must be provided for rigid pipes such as steel, cast iron, or aluminum, but the more flexible polyethylene can be laid directly on the ground or on wooden supports. Anchor blocks should be placed around the bends of all types of pipes. A

thrust block should be built at the lower end of the pipeline, just upstream of the powerhouse.

Powerhouse

The size of the powerhouse is determined by the type and size of the turbine installed. Figure 1.6 shows typical layouts for Pelton and Francis turbines. A low head plant (less than 10 m head) looks quite different: See Chapter 5 for details.

The substructure -- which consists of the pedestal of the turbine and generator, the draft-tube or discharge pit, and the floor slab - should be made of concrete. The superstructure -which is above the floor and protects the machinery and electrical controls from rain, heat, cold and vandalism -- can be made of wood frame, metal frame, concrete block, log or self supporting metal panels. Make sure that the superstructure allows the turbine and generator to be installed and removed for repair.

Tailrace

The tailrace is a channel which leads the water from the turbine back into the stream, a lake or the sea. It should prevent the water from damaging any structure or the landscape. 

1.5.4 Low, Medium and High Head

Low, medium and high head are terms used to indicate the most suitable type of turbine for the project. The various types of turbines listed in the table below are described in Section 4, "Turbines".

- Low Head up to 10 m Use: Cross-flow, axial-flow or propeller turbine

- Medium Head 10 m to 200 m Use: Cross-flow, Francis, Pelton or Turgo turbine

- High Head 200 m to 1000 m Use: Pelton, Turgo-impulse or Francis turbine

1.5.5 Existing Dams

If there is already a dam on a stream nearby, you should consider using it. First, find out who owns it, then try to assess what repairs would have to be done if you were to use it as an intake dam or a small storage dam. Could you incorporate in the dam an intake for a pipeline? You should have an engineer check the dam before further developing your plans for its use. You should also check with Water Management Branch as a changed use could require the dam to be upgraded.

1.5.6 Transmission Line

If your load (i.e. house, bunkhouse, sawmill, etc.) is more than 100 m from your powerhouse, you will need a transmission line, and probably step-up and step-down transformers. Transmission lines are expensive ($17,000/km or more) so always plan to put the powerhouse as close as possible to your load; however, they are less expensive than pipelines so a trade off must be made.

1.6....... AVAILABLE POWER AND ENERGY (Back)

Now that you have measured, or estimated, the lowest expected flow (Qmin) and gross head (Hg), you can calculate the power and energy available from the stream. To calculate power, use the nomograph in Figure 1.3, or the power Equation 1-3, as explained in Section 1.6.1.   The calculation of energy is explained in Section 1.6.4.

1.6.1 Firm Power

Firm Power is the power that is always available from the stream, even at times of lowest flow and lowest head. To calculate firm power you use the lowest expected flow in the stream (Qmin) and the gross head (Hg). In the case of a low head plant (less than about 10 m) in which the forebay level varies, the gross head should be measured to the minimum forebay level.

Using these new symbols for Q and H, the power equation (1-2)

becomes:      FIRM POWER (Pfirm) = Qmin x Hg x 5.9 kW (1-3)

Remember, in this equation, the overall plant efficiency is assumed to be 60 percent because of head loss in the pipeline, and turbine and generator efficiencies. The nomograph in Figure 1.3 was drawn from this equation.

With the values of Qmin and Hg that you have written into Table 1.3, use the nomograph in Figure 1.3 to calculate the firm power Pfirm.

Example:

Example Your Values

On the nomograph enter:

Qmin 200 1/s 1/8

Hg 30 m m

From the nomograph:

Pfirm 35 kW kW

Write your Pfirm value - the firm power available from the stream into Table 1.3.

1.6.2 Design Capacity of Hydro Plant

The design capacity (or installed capacity) of your hydro plant is the maximum power it can produce. For this stage in the planning process, assume that the design capacity is made equal to the maximum load, using some load management, as discussed in section 1.2.2. Also, assume that the plant can produce maximum output -equal to the maximum controlled load -- when the flow in the stream is at its lowest. This means that the plant will be able to produce all the power you need, even during dry periods.

These assumptions are summarized:

Design capacity of plant (kW) = Maximum load (kW) = Firm power (kW)

This is a simplifying assumption that is satisfactory for the calculations in Chapter 1, a more detailed analysis is made in later chapters.

1.6.3 Storage Reservoir

If your hydro plant cannot produce enough power to meet your peak load when the streamflow is low, you can:

(a) build a dam and create a storage reservoir, or

(b) Use a diesel generator or other source of power during low flow periods.

The stream might dry up completely in the summer or in the winter after several weeks of very cold weather. Even with a storage reservoir or an alternative source of power for these short no-flow periods, a hydro project might still be economic.

Decide if you want to build a storage dam or use an alternative source of power. If you already have a diesel generator, you might choose to use that. If there is a lake upstream of your planned pipeline intake, you might choose to build a small dam at the outlet of the lake to control storage.

You do not have enough information yet to calculate the volume of storage you require, or the height of the dam. How to calculate these is described in Chapter 3. Until then, if you plan to build a dam, follow the guidelines in Section 1.8.1 for

including an allowance for the cost of the dam.

1.6.4 Energy

Next, estimate the average annual energy that you will use from your hydro plant. You will need this in Section 1.8.2 to estimate your hydro energy cost (cents/kW.h). By comparing this cost with the cost of alternative sources of energy, such as a diesel generator or energy from a B.C. Hydro power line, you can decide if you wish to build the hydro project.

The amount of energy that you will use from your hydro plant will depend on:

(a) the design capacity of the plant, compared to the flow and head available in the stream, and

(b) the variations in your load (discussed in Section 1.2.1).

For each plant and stream, there is a specific set of conditions which has to be known before you can calculate accurately the average annual energy output.

At this stage you do not have enough data, and simplifications must be made.

If you wanted to generate constant power equal to your maximum load (assuming some degree of load management), the annual energy output would be:

B (annual) = Pdesign x 8760 kW.h (1-4)

Where:

E (annual) = Annual energy output (kW.h).

Pdesign = Firm power (kW) calculated in Section 1.6.1. 8760 = Number of hours in a year.

However, your load will not be constant (as discussed in Section 1.2.1) and the design capacity of the plant (Pdesign) would probably be larger than your maximum load, to include the possibility of increased loads in the future. You will also have to shut down the plant for maintenance. For these reasons, your actual annual energy output will be less than indicated by Equation (1-4). To account for this, a Plant Factor (or Capacity Factor) is used:

Plant Factor (PF) Average power generated during year Plant design capacity (Pdesign)

The average annual energy output would then be:

E (annual) = Pdesign x PF x 8760 kWh (1-5)

Plant factors describe the way in which a plant operates over a period of time, say, for several years.

For these preliminary estimates of average annual energy, use a plant factor of 80 percent. (A plant factor of 80 percent applies to a system with automatic load management. If you do not intend to use automatic load management, use a plant factor of 50 percent.)

Average annual energy is:

E (annual) = Pdesign x 0.8 x 8760 (1-6)

= Pdesign x 7000 kw.h

Example:

In the previous examples in Section 1.6.1 we calculated the Firm Power output of a stream to be 35 kW. Assume that the plant is designed to produce maximum power equal to this Firm Power from the stream.

Using Equation (1-6), the average annual energy used is:

E (annual) = 35 x 7000 kW.h

= 245,000 kW.h

1.7....... ADVISORS (Back)

Turbine manufacturers, pipe suppliers, contractors and electricians will give you free advice. owners of small hydro plants, particularly those who have built their own, will usually be pleased to tell you about their experiences and offer advice.

1.7.1 Engineers

You can hire an engineer to do part or all of the design of the project. An engineer can

(a) advise on specific problems such as, safety of the existing dam you might want to use; foundations for a dam, pipeline supports or powerhouse; type of electrical or mechanical equipment;

(b) design certain structures such as a dam, pipeline supports, an electrical load control panel, or a turbine;

(c) make a preliminary study to confirm the feasibility of the project;

(d) prepare a feasibility report for a bank or investor from whom you want to borrow money; or

(e) design and supervise the construction of the project.

Guidelines on the cost of these services are given in Section 1.8.1, "Engineering Costs".

Before you hire an engineer, contractor or any other professional person, ask for an estimate of the cost of services and expenses to be paid. Ask him to write down exactly what he will do and how long it will take. Make sure you understand what he said he would do, and that this is what you want. When he's finished the job and you want him to do more, or he suggests doing more, again, ask for an estimate on the additional work. In that way you are in control of your expenses and you will avoid unpleasant surprises when you receive his bill.

The decision to hire an engineer is yours, but there are typical situations under which you are advised to hire an engineer:

(a) Dam Design: If you need to build a storage dam, or if your intake dam is more than 1.5 metres high, an engineer should check the design and the foundations.

(b) Existing Dam: If you plan to use an existing dam to store water, an engineer should check the safety of the dam.

(c) Pipeline: If the head is greater than 30 m; if the length is longer than 300 m; or if the diameter is larger than 0.5 m an engineer should review your design for waterhammer, pipe strength, pipe supports and anchors. These limits are abribtrary and may not apply to all sites.

(d) Excavations: If you have to excavate into a steep or unstable looking side slope for an access road, pipeline or the powerhouse, an engineer should first check the stability of the slope.

(e) Safety If there are residences downstream of any part of the project and you will be changing the natural stream channel or leading water out of the natural channel in a canal or pipeline), an engineer should check the safety of the project.

1.8.......PROJECT COSTS (Back)

1.8.1 Capital Costs

Your project cost estimates will be very preliminary at this stage. You can use the cost curves in Figure 1-7 to 1-12 to find the cost of most of the components of your project.

You might want to buy used equipment or materials, such as:

- turbine- pump - to be operated in reverse as a turbine- generator- other electrical equipment and wiring- steel or plastic pipe

You can save 50 percent or more on the cost of new items. Ask turbine manufacturers if they have a used turbine or generator that would suit your project. Scrapyards and used equipment dealers are places to look for pumps, valves, electrical equipment, wire and pipe. Used equipment and materials are advertised in newspapers and trade journals and magazines.

No costs for used equipment are given in this manual -- you will have to estimate costs based on your own enquiries. Beware, there are no guarantees on used equipment or materials, so make sure you know what to look for to check that the equipment or materials are in good condition.

When you have estimated the cost of each component, write it into the Summary of Project Costs, near the end of this section.

Site Preparation

Timber and brush will probably have to be cleared at the site of the intake, along the pipeline, at the powerhouse and along the transmission line. The storage reservoir, if you need one will have to be cleared before you flood the area. A cat track or access road might have to be built to get construction materials and equipment to the intake, pipeline or powerhouse.

The cost of the work depends on the conditions at the site, therefore no cost curves are given to help you make an estimate. You could ask a local contractor, logger or cat owner for an approximate price.

Remember to include a cost -- even if it is only a guess -- for site preparation in your project cost estimate.

Storage Dam

You decided in Section 1.6.3 whether or not you needed a storage dam. At this stage you cannot make a reliable estimate of the cost of the dam. However, if you need to build a dam, include a cost for it in the Summary of Project Costs to remind yourselt that a dam could be a major part of the project cost. use the larger of the following alternative costs:

(a) twice the cost of the intake weir (to be estimated next), or

(b) ten percent of the total civil, mechanical and electrical costs (to be calculated in the Summary of Project Costs at the end of this section).

Intake weir

The intake weir could be built of concrete, rock gabions or rock-filled timber crib. A concrete dam would probably be the most expensive, a rock-filled dam the least expensive. Cost curves for concrete and gabion weirs only have been given in Figure 1.8. If you plan to build a timber-crib dam, you can make your own cost estimate or use the cost curve for the gabion weir, knowing that you are probably over estimating the cost of a timber-crib weir.

The curves in Figure 1.8 are for work done by a building contractor who pays union wages. Costs can be as low as 60 percent of the costs shown in Figure 1.8 if you do not hire a contractor and if the following conditions apply:

(a) you do most of the work yourself or pay wages at $12 per hour. and

(b) for the concrete dam you mix concrete at the site, or

(c) for the gabion dam you do not have to pay for delivery of rocks for the gabions because there are rocks close to the site.

To find the cost of the weir using Figure 1.8:

(a) decide on the type of weir you will build,

(b) decide on the height of the weir

(c) select the height on the vertical axis, then read off the cost per metre of weir on the horizontal axis,

(d) estimate the length of weir, and

(e) calculate the cost using the formula cost of weir = cost/m x length (m).

Example:

Concrete weir 1.5 m high, 6 m long, built by contractor.

Using Figure 1-8:

Example Your Values

Weir height ..................................... 1.5m .....................................................m

Weir Length .....................................6.0m ......................................................m

Cost per length of weir (b) .. 210 $/m ..................................................$/M

Cost of weir (a x b)...........................1260 $ .......................................................$

Pipeline Intake

In Figure 1.9 cost curves are shown for a free-standing intake for a gabion or rock-filled timber weir, and for an intake for a concrete weir where the backwall of the intake would be part of the concrete dam.

To find the cost of the intake using Figure 1.9

(a) select the pipeline diameter,

(b) find the submergence required for this pipe diameter, using the bottom graph,

(c) estimate the actual height of the intake (the headpond behind the intake weir might be deeper than the minimum height required in Item 2 above),

(d) find the cost of the intake for the correct pipeline diameter, using the top graph, and

(e) add the cost of the trashrack from the middle graph.

Example:

Pipe diameter (Section 1.5.3. "Pipeline") D = 410 mm

Submergence required (bottom graph Figure 1.9) = 1.0 m

Height of intake = height of weir (1.5 m) + 0.5 m = 2.0 m

Cost of intake (using 500 mm pipe diameter on Figure 1.9) = $670

Cost of trashrack for 400 mm pipe (middle graph figure 1.9) $180

Total Cost of Intake $850

Pipeline

Before you can calculate the cost of the pipeline, you must first make a sketch of the pipeline route (as shown in Sketch (A) in Figure 1.10) and mark a few ground elevations and lengths along the pipeline to define the profile. For example, EL. 10 m, EL. 20 m, EL. 30 m; and Ll, L2, L3' This will enable you to estimate the head on various sections of the pipeline, (as shown in Sketch (B)) and to choose the correct cost for each section: this applies to polyethylene plastic pipes only.

In the table on Figure 1.10, Column #1 shows a Pipe Classification which corres nds to a range of Gross Heads (or pressure heads) in Column #2. Each classification of pipe can withstand a pressure head equal to the maximum in the range in Column #2, for example, "A" pipe can withstand a gross head up to 31.6 m, and "B" pipe a gross head of 42.2 m. This classification is for polyethylene pipe only; steel pipe is strong enough to withstand a gross head in excess of 150 m.

For costing polyethylene pipe, mark off the maximum gross head in each classification on your sketch of the pipeline starting from the intake, as in Sketch (B), Figure 1.10. Then measure the length of each classification of pipe, for example LA, LB, LC in Sketch (B).

For each classification, read from the table on Figure 1.10 the cost per metre of pipe under the appropriate pipe diameter; multiply that unit cost by the length for that classification to give the cost of that section of pipe.

Example:

Pipe diameter - 410 mm inside diameter. Assume a nominal outside diameter of 45U mm.

Draw a table as shown below. The lengths LA, LB etc. are taken from your sketch, similar to Figure 1.10, Sketch (B). The unit costs of pipe per metre are taken from the table on Figure 1.10. We will assume a 500 mm pipe in this example, but you could interpolate the cost for a 450 mm diameter pipe between the costs for pipes of 315 mm and 500 im-n.

Pipe Length Unit Cost Cost of Section

Classification m $/m $

A LA = 50 155 7750

B LB = 10 205 2050

C LC = 20 265 5300

D LD = 13 324 4212

E LE = 13 518 6734

F LF = 10 518 5180

Total Cost of Pipeline $31,226

Note that the unit costs of 500 mm diameter pipe in Classes E and F are below the heavy line in the table, indicating that they are steel pipe. A polyethylene pipe of that diameter cannot withstand a gross head greater than 70.3 m (classification D).

Add the cost of a valve, from the table on Figure 1.10, to get the total cost of the pipeline.

Powerhouse

Figure 1.11 shows cost curves for the powerhouse sub-structure (concrete foundations and floor) and superstructure (wood or prefabricated metal).

For the sub-structure cost you need the rated output of your hydro plant in kW, which you should already have estimated. Use the top graph on Figure 1.11 to find the sub-structure cost.

The superstructure floor area depends on the physical dimensions of the turbine and generator. The size is related to the penstock diameter. Use the bottom graph on Figure 1.11 to find the cost of the superstructure for the penstock size and type of turbine you have selected.

Add the costs of the sub-structure and superstructure to get the total powerhouse cost.

Turbine, Generator and Electrical Equipment

Use Figure 1.12 to estimate the cost of the turbine, generator and electrical equipment in the powerhouse. You need to know the gross head (from Section 1.4.2) and the energy output hydro plant in kW. To find the cost of the equipment, find the head on the vertical axis, draw a line horizontally to intersect the diagonal line with the correct range of plant output (you can interpolate between these lines), then draw a vertical line down to the horizontal axis. Read the cost (in $/kW) of the equipment and multiply by the plant output in kW.

The cost lines on Figure 1.12 were derived from manufacturers prices and show average costs. They should be used only for initial estimates, since the prices you actually pay for the turbine, generator and other electrical equipment could be as much as 40 percent less than the costs given on Figure 1.12. You will generally get the quality you pay for: low-priced turbines will probably be made of cheaper materials and will probably require more repair than higher-priced turbines.

A very small turbine-generator unit (1.0 - 1.5 kw) with batteries and a battery-charger might be suitable for lighting and a few appliances in a small, well-insulated house or summer cabin. The cost of turbine, generator, batteries, and inverter would be about

1.0 kW $ 9000

1.5 kW $13000

Remember, if you will be converting from existing oil or propane heating to electric heating, there will be additional costs for electric heaters and wiring at your house, lodge, camp, or mill. These additional costs are not covered in this manual.

Transmission Lines and Cables

Use the table below to estimate the cost of transmission lines or cables running from the hydro plant to the load. Refer to Chapter 4 for a discussion of voltages and different types and sizes of cable you should use.

Wood Pole Transmission Line

3-phase, 2.4 kV, up to 250 kW: $17000/km

High Voltage Buried Cable

single-phase, up to 85 kW: $15000/km

Tailrace Channel

The tailrace channel is usually a minor cost item, however, a cost figure should be included in the estimate. A cost curve cannot be prepared for the tailrace channel because the channel dimensions depend entirely on the site. Make your own estimate for this item or ask for an estimate from the person who advised you on the clearing and access costs.

Contingencies

Contingencies are unexpected costs.

The cost curves in Figure 1.8 to 1.12 were drawn using cost estimates from manufacturers, suppliers and contractors, and using costs of projects recently built. However, the cost of your project will probably be more than you have estimated so far: that's the way things usually turn out. Some reasons for this:

1. The project you build might be more complicated than the one you have planned.

2. The dimensions of the project you build might be larger than you have estimated.

3. The cost curves do not include every possible expense.

4. Unexpected problems will probably arise during construction.

5. Add more if the project has accessability problems.

To avoid surprises, be conservative. Add a contingency item to your cost estimate, as follows:

1. Add 15 percent if you think your project will be easy to build, and you think you have included everything.

2. Add 25 percent if you think your project might be more complicated than most, or if you think you might have underestimated some of the dimensions such as, length of penstock or transmission line.

Engineering Costs

You have probably decided whether or not you will hire an engineer. This section suggests costs to expect for engineering services.

Even if you want to do all the planning yourself, you should still provide for the cost of expert advice you might need unexpectedly.

If you do hire an engineer, here are some guidelines to help you estimate the costs. For

advice on specific problems, or the design of certain structures, engineers normally charge hourly or daily rates for their services:

$30 to $70 per hour; $200 to $500 per day.

For a visit to the site, an engineer would expect to be paid, probably at a reduced rate, while he was travelling, and he would want to be paid for reasonable expenses. Generally, a self-employed engineer will charge less than a firm of engineers which has to cover higher overheads.

If you have to borrow money to build the project, the banks, or other investor, may ask for a feasibility study report to show:

(a) the availability of a site for your project,

(b) the availability of sufficient flow and head to produce the power and energy you need,

(c) an estimate of the costs of the project, and

(d) a simple financial analysis showing loan repayments and other facts the bank or investor might require.

For a feasibility study and report, expect to pay between a minimum of $2000 (that would be a nominal fee) and, $7000 to $15000 for a project of 50 kW to 250 kW.

For a feasibility study report, and the complete design and construction supervision of a project, expect to pay 5 to 15 percent of the project cost, or a minimum of $8000.

Remember, before you hire an engineer or other expert, ask for an estimate of the cost and a letter detailing exactly what the engineer will do for the money.

Summary of Project Costs

Make a list of all the costs that apply to your project.

Example Costs Your Project Costs

Clearing and Access $1000 ......................$

Storage Dam $0 ......................$

Intake $1300 .....................$

Pipeline $31900 .....................$

Turbine, Generator, Electrical Equipment $45500 .....................$

Powerhouse $10700 .....................$

Transmission Line $8000 ....................$

TOTAL COST OF STRUCTURES AND EQUIPMENT (a) $98400 ....................$

Engineering $7000 ....................$

Contingencies (15% of (a)) $15000 ....................$

TOTAL PROJECT COST $120,400 ....................$

Cost per kW

To check the cost of your project, compare its "Cost per kW" with other plants. To get the cost in $/kW, divide the total project cost by the design capacity of the plant (from Section 1.6.2).

Example Your Figures

Total Project Cost (from Summary of Project Costs) $120,400 ..................................$

Design Capacity (from Section 1.6.2) 35 kW ..............................kW

Cost per kW...............................3,440 $/kW ...........................$/kW

The cost per kW should be within the range of $2000 to $5000 per kW.

If your figure is around $2000 per kW you have a good project. If the figure is around $5000 per kW, you still might have a project that is cheaper than an alternative power source, such as diesel. You will know this when you have calculated the annual cost of your plant in Section 1.8.2.

Degree of Confidence in Project Cost Estimate

Only an approximation of the actual project cost can be expected at this stage in the planning process, when the structures have yet to be designed and the sites have yet to be carefully examined. Nevertheless, the actual project cost will probably be within 25 percent of your estimate.

1.8.2 Annual Costs

You should be aware of the annual cost of energy, including loan payments and maintenance and repair costs, of your hydro project. You might want to compare that cost with the cost of energy from a diesel generator or from a nearby transmission line.

Loan Payments

Decide how much you will have to borrow to cover the total project cost, then calculate your annual payments (capital and interest) using a Capital Cost Recovery Factor (CRF) from Table 1.2.

Example:

Assume you want to repay a loan in 10 years, and the interest rate is 10 percent.

Example Your Values

- Total Project Cost $120400 $..............................

- Equity Available for Project $ 30400 $..............................

- Loan Required (a) $ 90000 $..............................

From Table 1.2:

For: n 10 years ........................years

I =10% ...............................%

Find: CRF 0.163 .................................

Annual Loan Payment:

(CRF) x (a) 0.163 x 90000 ........................X......................

=....... $14,670 $...............................................

Maintenance and Repair Costs

Maintenance and repair costs include maintaining the intake, dam, pipeline, powerhouse and the mechanical and electrical equipment. The maintenance work that should be done is discussed in Chapter 3. However, for this initial estimate of

annual costs, use 2% of the Total Project Cost, or $2000 minimum annual maintenance cost.

Total Annual Costs

Add the annual loan payments and the annual maintenance and repair costs to get the total annual cost. Divide this by the estimated annual energy output (from Section 1.6.4) to get the cost per kW.h.

Example: 

Example Your Values

- Annual Loan Payment $14,670 ...........$

- Annual Maintenance & Repair Costs $ 2400 ...........$

-Total Annual Costs (a) $17,070 ...........$Annual Energy Output (from section 1.6.4) (b) 245000 kW.h kW.h

- Cost per kW.h = (a) x 100/(b) = 7.0cents/kW.h cents/kW.h

1.9 ..........Project Worth (Back)

1.10 ..........Continued Planning (Back)

1.11 ..........Project Data Summary (Back)

SUPPLEMENT / MEASURING HEAD AND STREAMFLOW / PRELIMINARY

CHAPTER #2 - SITE EXPLORATION AND STREAMFLOW DATA

2.1 ..........Introduction

2.2 ..........Topographic Maps

2.3 ..........Streamflow Data

2.4 ..........Streamflow Measurement

2.5 ..........Water Quality

2.6 ..........Site Selection for Project Structure

2.7 ..........Head Measurement

2.8 ..........Pipeline Length

2.9 ..........Project Site Topography

2.10 ..........Environmental Aspects

SUPPLEMENT 2.1:

Maps, Air Photos, Streamflow and Climate Data

SUPPLEMENT 2.2:

Installing a Staff Gauge and Weir to Measure Streamflow

CHAPTER #3 - ASSESSMENT OF THE FEASIBILITY OF YOUR HYDRO MANUAL

3.1 ..........Introduction

3.2 ..........Power and Energy Requirements

3.3 ..........Load Planning and Management

3.4 ..........Power and Energy Availability

3.5 ..........Small Hydro Plant Sizing

3.6 ..........Preliminary Arrangement of Structures and Selection of Equipment

3.7 ..........Project Costs

3.8 ..........Preliminary Assessment of Feasibility

3.9 ..........Continued Planning

SUPPLEMENT 3.1:

Flow Duration Curves

SUPPLEMENT 3.2

Calculating Reservoir Storage

SUPPLEMENT 3.3

Information from Turbine-Generator Manufacturers and Suppliers

CHAPTER #4 - CIVIL WORKS AND EQUIPMENT

Introduction

4.1 ..........Dams

4.2 ..........Intake Structures

4.3 ..........Diversions

4.4 ..........Maintenance of Dams and Intakes

4.5 ..........Factors affecting costs and construction

4.6 ..........Penstock Design

4.7 ..........Characteristics of Pipes

4.8 ..........Plastic Penstocks

4.9 ..........Steel Penstocks

4.10 ..........Forces and Trust Blocking

4.11 ..........Installation of Penstocks

4.12 ..........Water Hammer

4.13 ..........Valves

4.14 ..........Canals, Flumes and Lines Channels

4.15 ..........Turbines

4.16 ..........Water Control to Turbine

4.17 ..........Mechanical Governors

4.18 ..........Electronic Load Control Governors

4.19 ..........Tailwater

4.20 ..........Draft Tubes

4.21 ..........Pumps as Turbines

4.22 ..........Generators

4.23 ..........Mechanical Power Transmission

4.24 ..........Induction Generators

4.25 ..........Synchronizing

4.26 ..........Power Factor

4.27 ..........Electrical Transmission

4.28 ..........Transformers

4.29 ..........Single and Three Phase Systems

4.30 ..........Automatic Emergency Shutdown

4.31 ..........Remote Alarms

4.32 ..........D.C. Systems

4.33 ..........Electrical Inspection and Codes

4.34 ..........Powerhouse Design

4.35 ..........Technical Requirements for Grid Connected Plants

4.36 ..........Consultants, Suppliers and Contractors

CHAPTER #5 - PERMITS, LICENSES AND LEGAL ASPECTS FOR SMALL HYDRO

5.1 ..........Introduction

5.2 ..........Local Involvement

5.3 ..........Provincial Involvement

5.4 ..........Federal Government

5.5 ..........Recommendations APPENDIX

CHAPTER #6 - ECONOMICS AND FINANCING

6.1 ..........Introduction

6.2 ..........Valuation of Energy

6.3 ..........Alternative Energy Costs

6.4 ..........Detailed Economic Assessment

6.5 ..........Financing Alternatives

CHAPTER #7 - GETTING STARTED

7.1 ..........General

7.2 ..........Project Scheduling

7.3 ..........Project Construction

7.4 ..........Practical Notes on Building a Small Hydro Plant

7.5 ..........Practical Notes on Dealing With a Contractor

7.6 ..........Conclusions

CHAPTER #8 - LOW HEAD CONSIDERATIONS

8.1 ..........Introduction

8.2 ..........Water Wheels

8.3 ..........Modern Turbine Types

8.4 ..........Package Visits

8.5 ..........Variable Heads

CHAPTER #9 - COLD WEATHER CONSIDERATIONS

9.1 .......... Cause and Effect

9.2 ..........Climate

9.3 ..........Frost

9.4 ..........Cold Weather

9.5 ..........Ice

9.7 ..........The Dam or Diversion Structure

9.8 ..........Intake Structure

9.9 ..........Canal

9.10 ..........Penstocks

9.11 ..........Powerhouse

9.12 ..........Transmission Lines

9.13 ..........Access

9.14 ..........Conclusion

CHAPTER #10 - ORGANIZATION AND OPERATION OF A PUBLIC UTILITY

10.1 ..........Introduction

10.2 ..........Rationale for Utility Regulation

10.3 ..........Relevant Registration

10.4 ..........Regulatory Alternatives

10.5 ..........Application Procedure

10.6 ..........Organizational Structure and Accounting Procedures

10.7 ..........Implications to Organizing and Operating as a Public Utility

*GLOSSARY*

A ..........Case Study Examples

B ..........Permit Applications and Agency Addresses

C ..........Small Hydro Suppliers and Contractors

D ..........Small Hydro Consultants

E ..........Small Hydro Computer Programs

F ..........Definitions

G ..........Sources of Financing

H ..........References

Ron Williamsrwilliam@wlake.com

usion 

CHAPTER #10 - ORGANIZATION AND OPERATION OF A PUBLIC UTILITY

10.1 ..........Introduction

10.2 ..........Rationale for Utility Regulation

10.3 ..........Relevant Registration

10.4 ..........Regulatory Alternatives

10.5 ..........Application Procedure

10.6 ..........Organizational Structure and Accounting Procedures

10.7 ..........Implications to Organizing and Operating as a Public Utility

*GLOSSARY*

A ..........Case Study Examples

B ..........Permit Applications and Agency Addresses

C ..........Small Hydro Suppliers and Contractors

D ..........Small Hydro Consultants

E ..........Small Hydro Computer Programs

F ..........Definitions

G ..........Sources of Financing

H ..........References

Ron Williams

TECHNICAL PAPER #5

UNDERSTANDING HYDROPOWER

ByWalter Eshenaur

Technical ReviewersRoger E. A. ArndtCharles DelisioPaul N. GarayChristopher D. Turner

Published By1600 Wilson Boulevard, Suite 500Arlington, Virginia 22209 USATel: 703/276-1800 . Fax 703/243-1865Internet: pr-info@vita.org

Understanding HydropowerISBN: 0-86619-205-0[C]1984, Volunteers in Technical Assistance

PREFACE

This paper is one of a series published by Volunteers in TechnicalAssistance to provide an introduction to specific state-of-the-arttechnologies of interest to people in developing countries.The papers are intended to be used as guidelines to helppeople choose technologies that are suitable to their situations.They are not intended to provide construction or implementationdetails. People are urged to contact VITA or a similar organizationfor further information and technical assistance if theyfind that a particular technology seems to meet their needs.

The papers in the series were written, reviewed, and illustratedalmost entirely by VITA Volunteer technical experts on a purelyvoluntary basis. Some 500 volunteers were involved in the productionof the first 100 titles issued, contributing approximately5,000 hours of their time. VITA staff included Leslie Gottschalkas primary editor, Julie Berman handling typesetting and layout,and Margaret Crouch as project manager.

Walter Eshenaur, author of this paper, is a research assistant inthe Department of Agricultural Engineering at the University ofMinnesota, where he specializes in energy technologies, particularlyhydropower. Reviewers Roger E.A. Arndt, Charles Delisio,Paul N. Garay, and Christopher D. Turner are also specialists inhydropower. Arndt, director of the St. Anthony Falls HydraulicLaboratory at the University of Minnesota, has taught hydropowerat the university and has written publications on the subject. Heis currently conducting research on a turbine test facility whichwill test various turbine designs. Delisio, a professional engineer,is employed at Flack and Kurtz Consulting Engineers. Duringhis affiliation with Yale University's Business School, he conducteda number of feasibility studies for hydropower projects at

existing sites in New England. Garay, an associate engineer withF.M.C. Associates, has written many papers on various aspects ofwater transportation and energy uses of water. Turner coordinatesthe Microhydro Development Grant of the Appalachian State University.He is currently managing construction of a microhydro siteat the Cherokee Indian Reservation in North Carolina.

VITA is a private, nonprofit organization that supports peopleworking on technical problems in developing countries. VITA offersinformation and assistance aimed at helping individuals andgroups to select and implement technologies appropriate to theirsituations. VITA maintains an international Inquiry Service, aspecialized documentation center, and a computerized roster ofvolunteer technical consultants; manages long-term field projects;and publishes a variety of technical manuals and papers.

UNDERSTANDING HYDROPOWER

By VITA Volunteer Walter Eshenaur

I. INTRODUCTION

Water quenches our thirst and bathes our bodies, but above all itprovides the foundation for life on this planet.

Through nature's physical laws, water can unleash powerful andsometimes destructive forces. One of these forces, governed bythe law of gravity, is demonstrated through the simplest ofphenomena: falling water. Over the centuries, people have triedto harness the energy of falling water to their benefit. Obtainingthis energy can be simple or nearly impossible, dependingupon which laws of nature govern. In the case of gravity andwater, nature's governing laws provide easy access to thisuseful and abundant energy.

FOCUS OF THE PAPER

Once it is understood that gravity and water can be harnessed toproduce energy, a study of methods to extract this energy efficientlycan be undertaken. The purpose of this paper is to discussseveral such methods in general terms. The paper provides abasic introduction to the science of water power (hydropower),along with an overview of state-of-the-art technology. It alsodiscusses the sequence of events from initial surveys to endresults to provide a well-rounded understanding of the use ofhydropower. Although there are other methods, this paper focuseson turbines and waterwheels.

PHILOSOPHY OF HYDROPOWER DEVELOPMENT

Gravity dictates that water must seek the lowest elevation possible.From mighty rivers to babbling streams, water flows downhill,expending energy as it moves. With this in mind, generalcalculations can be used to determine, on a worldwide basis, theamount of energy available. Figure 1 provides some general quantities

fig1pg2.gif (600x600)

of world hydropower resources. In more scientific terms,this is known as the installed and uninstalled capability toproduce energy. Directing water to flow over a pre-determinedcourse permits energy to be extracted, whereas under naturalconditions this may be impossible.

A predetermined course implies human intervention. It alsoimplies a need for this type of energy. Need, coupled with theability to extract energy artificially (intervention), providesthe basis for a study of available resources, which in turnproduces quantitative results. These results can then be used todesign an appropriate hydropower system providing energy based onneed, yet minimizing adverse environmental effects.

Before any detailed analysis of a hydropower system can be understood,

a short history of turbines and the machinery supportingthem must be presented.

HISTORY OF HYDROPOWER DEVICES

Hydraulic turbines and waterwheels are most commonly used toextract energy from falling water. Turbines as we know them todayfall into two categories: reaction and impulse. Reaction turbinesuse both pressure and velocity forces of water to producetorque. This torque is then used to produce electrical or mechanicalenergy. Impulse turbines derive their torque or power fromthe momentum of a jet of water striking a series of blades. Thewaterwheel, however, is the forerunner of both the impulse andthe reaction turbine.

The waterwheel, a distant grandfather of the impulse turbine,played an important role in prompting engineers such as JohnSmeaton of England (1724-1792) to study and improve it until itsefficiency had reached about 70 percent (Arndt et al., 1981).

Development of a turbine using the same basic principles as thewaterwheel was initiated by engineers Zuppinger in 1846 andSchwamkrug in 1850. An important step away from the waterwheelwas initiated at that time with the development of a water spoutor nozzle that directs a high-velocity stream of water againstblades set in a wheel. Along with this development and the descriptionof an efficient waterwheel as stated by Poncelet in1826, a group of engineers from California set out to develop animpulse turbine with an efficiency higher than that of the waterwheel.Among this group was Lester A. Pelton (1829-1908), who wasresponsible for the development of a highly efficient impulsewheel that bears his name to this day.

The Pelton wheel, or turbine, although quite efficient, wasimproved by Eric Crewdson in 1920. This improvement led to thedevelopment of the Turgo wheel, which boasts even higher efficiencyand simpler construction than either the Pelton wheel orthe waterwheel.

Nevertheless, impulse wheels have been upstaged in recent yearsby more complex and efficient reaction turbines. Reaction turbinesalso use water momentum, but pressure forces are added forincreased torque. The Kaplan or propeller turbine, developedaround the time that Lester Pelton was perfecting his impulsemachine, has been a very popular machine throughout its history.The Kaplan turbine's high efficiency under low beads (pressures)accounts for its growing popularity today because many installationshave high flows but low heads. Other reaction turbinesdeveloped around the same time include the Francis turbine andother propeller machines.

Hybrid impulse turbines, which circumvent some basic drawbacks offull impulse machines, are known as cross-flow turbines. Thefirst cross-flow turbine was patented by A.G.M. Michell in 1903.Professor Donat Banki also developed a cross-flow turbine in 1917that bears his name today. Because these turbines are simple tobuild, they have been widely used in developing countries where

both low cost and simple technology are imperative.

As we can see from the above discussion, contemporary turbinetheory is a mature science. Today, the majority of researchinvolves fine-tuning basic designs and increasing the efficiencyof peripheral equipment such as governors (devices used for maintaininguniform speed in turbines) and electrical generators.

II. OPERATING PRINCIPLES

GENERAL THEORY OF TURBINES

Specific operational theory of various turbines is not within thescope of this paper. However, a general theory, covering allturbines and waterwheels, is provided in this section of thepaper to aid readers in understanding the broad applications ofturbines. More detailed turbine theory is generally useful onlyto builders or manufacturers, and is not necessary for projectdevelopers or engineers.

All hydropower machines--whether reaction, impulse, or waterwheels--aredriven by the same force: gravity. Gravity causes acertain potential energy to exist in a body of water. Using thisenergy to provide useful work requires a change in elevation overtime. Elevation change over time implies a conversion of potentialenergy to kinetic energy. Potential energy can be quantitativelyexpressed in many ways, but for the purpose of thispaper, the term "head" will be used. Read is the expression of apressure exerted on a body or part of a body in terms of feet ofwater. Because water is a principal fluid used in hydropower,this is a useful concept. Let us take, for example, a lake surfacethat is situated 1,000 meters above sea level. A hydroelectricplant is to be installed at an elevation of 800 metersabove sea level using the lake water to produce power. The head,which is theoretically available to convert potential energy tokinetic energy, is 200 meters (the 200 meters is arrived at bysubtracting 800 meters from 1,000 meters). This is known as grosshead, or Hg. Figure 2 represents a perfect gross head, where the

fig2pg6.gif (600x600)

gross head is the elevation between the upper and lower waterlevels. In reality, this total gross head is not available to theturbine due to friction losses in delivery pipes (penstocks) anda velocity head at the outlet (tailrace) which signifies kineticenergy lost due to velocity. Once these fractional and velocitylosses have been quantified in the form of head loss, they mustbe subtracted from the gross head. Gross head minus head lossesgives the total head available to the turbine. This is called nethead, or H. Once H has been determined, other major parametersdescribing the turbine can be defined. These are discussed in thesections that follow.

Power

Power is defined as the amount of energy that can be produced fora given H. A simple relation is given by the equation

eq1pg5.gif (353x353)

(Equation 1)

where P is kilowatts (when metric units are used), Q isdischarge at the end of the penstock, E is the efficiency of theturbine and W is the weight of the water.The power of a free jetof water streaming from the penstock is given by the equation

eq2pg5.gif (285x285)

(Equation 2)

where g is the acceleration due to gravity, and V is the jetvelocity.

Efficiency

The efficiency of the general power equation given in the previoussection can be divided into three parts: volumetric,hydraulic, and mechanical efficiency. Volumetric efficiency isdefined as the ratio of the water acting on turbine blades to thetotal water entering the turbine casing. For impulse turbines,nearly all the water entering strikes the blades; thus, thisefficiency is close to one. The volumetric efficiency of reactionturbines is virtually the same as impulse, but waterwheels willbe lower due to water spillage.

Hydraulic efficiency is defined as the power input to the turbineshaft divided by the power input to the turbine blades. Thisefficiency is the lowest of the three efficiencies and varieswidely among designs.

The third type of efficiency is mechanical efficiency. It isdefined as the power transmitted through the turbine shaft to thegenerator. It describes any mechanical friction losses.

The overall efficiency is the product of the three efficiencies,or:

(Equation 3)

eq3pg7.gif (150x393)

where [E.sub.v] and [E.sub.n] and [E.sub.m] are the volumetric, hydraulic andmechanical efficiencies, respectively. This overall efficiencycan be used in either designing or selecting a turbine.

Specific Speed

Another equation, independent of the type of machine, would beuseful in choosing a turbine and its proper speed for a particularsite, given a power capacity and net head. The equation is:

eq4pg7.gif (135x285)

(Equation 4)

where Omega is the speed of the turbine in radiansper second, D isthe density of water, P is the power (as defined in equation 1),g is the acceleration due to gravity, and H is the net head. Notethat because this is a dimensionless number, it can be applied toany situation.

Another specific speed that is more commonly used is given by theequation

(Equation 5)

eq5pg7.gif (108x353)

where [n.sub.s] is the speed of the turbine in revolutions per minute, Pis the power in horsepower or kilowatts, and H is the net head infeet or meters. This specific speed is not dimensionless; itsnumerical value depends on the system of units being used. Threerelationships between [N.sub.s] and [n.sub.s]--depending on the system ofunits--are:

[n.sub.s] = 43.5 [N.sub.s] (English units)

[n.sub.s] = 193.1 [N.sub.s] (metric units using metric horsepower)

[n.sub.s] = 166 [N.sub.s] (metric units using kilowatts).

Once the specific speed is known, the proper turbine can beselected on the basis of each turbine's rated specific speed variability.Figure 3 shows various turbines and their dimensional

fig3pg9.gif (600x600)

specific speeds. Waterwheels fall under Pelton and Francisturbine specific speeds, depending upon whether they are overshot([n.sub.s] = 1 to 50) or undershot ([n.sub.s] = 30 to 100), and can reachefficiencies of 70 percent.

Selection of a particular turbine is done by determining the rpmneeded (for electrical generation, rpm is rated according to thetype of generator and gearing, whereas mechanical power will haveinstallation-specific rpm requirements), and calculating thepower required (based on need) and the head available (sitespecific). Once these parameters are determined, the specificspeed can be found. As shown in Figure 3, the most efficientturbine for a particular specific speed should be used. Selectionof a particular turbine also depends on cost, and the level oftechnology desired.

Waterwheels are more difficult to select. Head and discharge canbe used to select specific designs rather than specific speed.Design manuals consider economics, low-level technology, cost,and ease of operation as high priorities in the selection ofwaterwheels over turbines. This implies serious consideration ofwaterwheel use in situations where the above factors are important.

An alternative method of turbine selection involves considerationof gross head and discharge. Turbines can be selected by usingthe quantities shown in Figure 4. Waterwheels are not shown in

fig4pg10.gif (600x600)

Figure 4, but they nevertheless tall under the Pelton and Francisturbine categories, probably in the lower, left corner of thefigure. It should be noted here that for waterwheels, Figures 3 and 4

fig3pg90.gif (600x600)

do not agree. This is due to the fact that waterwheelsoperate best under low heads and low discharges, causing the rpmto be very low. Thus, Figure 3 shows that a waterwheel can competewith a Francis turbine, whereas Figure 4 indicates use of awaterwheel, not Pelton or Francis turbines. Generally, both Peltonand Francis turbines are recommended for use with high netheads and high discharges, whereas waterwheels are meant to beused with low net heads and low discharges.

III. DESIGN VARIATIONS

TYPES OF TURBINES

Thus far, we have described specific turbines according to the

names of people who developed them, without describing their physicalcharacteristics. In this section, these characteristics arediscussed to aid further in the selection of specific water-powerdevices. Again, to facilitate the discussion, water-power machinesare grouped under the following three headings: reactionturbines, impulse turbines, and waterwheels.

Reaction Turbines

Reaction turbines use both velocity and pressure forces toproduce power. Consequently, large surfaces over which theseforces can act are needed. Also, flow direction as the waterenters the turbine is important.

Figure 5 shows the basic design of a Francis turbine. Francis

fig5pg12.gif (600x600)

turbines include a complex vane arrangement (see Figure 5) surroundingthe turbine itself (also called the runner). Water isintroduced around the runner through these vanes and then fallsthrough the runner, causing it to spin. Velocity force is appliedthrough the vanes by causing the water to strike the bladesof the runner at an angle. Pressure forces are much more subtleand difficult to explain. In general, pressure forces are causedby the flowing water. As the water flows across the blades, itcauses a pressure drop on the back of the blades. This in turninduces a force on the front, and along with velocity forces,causes torque. Francis turbines are usually designed specificallyfor their intended installation; with the complicated vane system,they are generally not used for microhydropower applications.Because of their specialized design, Francis turbines arevery efficient yet very costly.

Propeller turbines are popular reaction machines. In Figure 6,

fig6pg12.gif (600x600)

the components of a specific propeller turbine called the Kaplanare shown. Although propeller turbines operate on the same basisas the Francis turbine, they are not as specifically designedsince both vanes and propellers (on the Kaplan) are adjustable.Variations include the bulb turbine which houses blades andgenerator in a sealed unit directly in the water stream, thestratflow turbine where the generator is attached and surroundsthe blades, and the tube turbine where the penstock bends justbefore or after the blades, allowing a shaft connected to theblades to protrude outside the penstock and connect to the generator.Propeller turbines are usually less costly but are usedalmost exclusively in large installations.

The speed of reaction turbines ranges from 100 to 200 rpm,

depending upon design and use. Speed is governed by the movablevanes, which alter the direction of water entering the turbine.These vanes in turn vary the pressure forces on the blades,causing a loss or gain of power and maintaining speed.

Because reaction turbines use pressure forces and thus run underreduced pressures, a phenomenon called cavitation can occur.Simply put, cavitation is the boiling of water due to lowpressure. Water will boil when pressure is reduced considerably;this phenomenon happens on the low pressure side of a reactionturbine blade. Cavitation occurs only at the leading edge of theblade and as pressures rise again near the trailing edge, cavitationceases. It is important for cavitation to cease because asthe water vapor returns to a liquid state, localized pressuresbecome tremendous. Such pressures have the equivalent force ofpounding a sledge hammer against the turbine blade. Bearing inmind the power of cavitation, this phenomenon should be reduceda minimum. This is accomplished by carefully monitoring flowvelocity and changing flow direction by use of the vanes. Theadvantages of reaction turbines include:

* high efficiencies;

* excellent power output at low heads;

* numerous designs that provide easy tailoring to specificinstallations; and

* the flexibility of choosing either horizontal or verticalinstallation.

The disadvantages of reaction turbines include:

* efficiency at specified heads and discharges but inefficiencywhen these vary;

* the need for accuracy in installation design;

* the possibility that cavitation will occur;

* the potential that nonuniform forces will destroy therunner;

* very strict design tolerances;

* costly civil works; and

* high manufacturing costs.

Because reaction turbines--whether Francis or propeller--havehigh efficiency and high power output, they are the best waterpowerdevices and should be pursued whenever possible.

On the other hand, these turbines are very expensive to build,highly sophisticated in design, and do not use locally-producedraw materials, making them unsuitable for use in developingcountries. Note also that they may not be readily available in

the small sizes needed for small installations. So, considerinstead the option of using centrifugal pumps, which can bereadily adapted to serve as hydroturbines in any practical powerrange. These pumps are readily available and come in many sizes,making it possible to satisfy the needs of the small hydropowercustomer. Also, because they are mass produced, they typicallycost less than half as much as the equivalent hydraulic turbine.In many small-hydro applications, a suitable turbine is simplyunavailable, and the cost of a custom model would be prohibitive.Centrifugal pumps are easier to install and maintain, and theyare simpler to operate. In addition, they are available in abroader range of designs than conventional turbines. Wet-pit,dry-pit, horizontal, vertical, and even submersible are just afew of the types of centrifugal pumps available.

All types of centrifugal pumps, from radial-flow to axial-flowdesigns, can be operated in reverse and used as hydraulicturbines. Tests have shown than when a centrifugal pump operatesas a turbine:

* its mechanical operation is smooth and quiet, and

* its peak efficiency as a turbine is essentially the sameas its peak efficiency as a pump.

One note of caution: a centrifugal pump used as a hydraulic turbine must be checked by a qualified hydraulic engineer before itgoes into operation to prevent damage to the impeller. When thepump operates as a turbine, it rotates in reverse so that operatingheads and power output are generally higher. To avoid damageto the impeller, the engineer has to check how much stress thepump can tolerate caused by the flow and pressure of the water.

Impulse Turbines

Impulse turbines derive their power from a jet stream striking aseries of blades or buckets. The Pelton wheel is probably themost well-known impulse machine, but others are now becomingpopular.

Figure 7 shows a Pelton wheel. Notice that one nozzle is being

fig7pg15.gif (600x600)

used, with its jet of water striking one bucket at a time. Sinceimpulse turbines operate at atmospheric pressures, cavitation isnot a concern. However, bucket design is very important becauseof the tremendous forces involved. Buckets are designed so thatthe stream of water is split in half and turned almost back uponitself. This design extracts maximum energy and negates axial(along the shaft) torque. Adding nozzles increases power outputlinearly, but a practical maximum is six nozzles. If the dischargeallows more than one nozzle, this is probably desirable.

Pelton and Turgo wheels are higher speed machines ranging inspeed from 1,000 to 3,600 rpm. This is advantageous whenelectrical generation is necessary, but high speed reduces torquewhich may be desirable for mechanical applications. If speedregulation in necessary, nozzle velocity can be controlled byusing a needle valve which decreases the water power available.

Figure 8 shows the blade arrangement of the Turgo wheel. Designed

fig8pg17.gif (600x600)

along the same lines as the Pelton wheel, the Turgo wheel allowsthe stream of water to strike several blades at one time. Thisincreases the power output since one blade is always under thefull force of the water jet.

Both the Pelton and Turgo wheels are well suited for high head,low discharge situations since water velocity is the governingforce and may be high under high heads while discharge is low.Cross-flow turbines use impulse theory yet operate somewhat differentlythan Pelton or Turgo wheels. Figure 9 shows a cross-flow

fig9pg17.gif (600x600)

turbine called the Banki turbine. Water exiting the nozzlestrikes several blades, producing torque. The blades direct thewater into the inner area of the turbine. The water travelsacross the inner diameter of the turbine and strikes the bladesagain at another location on the turbine, creating additionaltorque. This novel design, though seemingly complex, lends itselfto easy construction on a local basis since this turbine does notuse a high-velocity water jet or special manufacturing techniquesas do the Pelton and Turgo wheels. Local materials can be usedsince the force of the water is distributed evenly throughout thelength of the turbine.

The operating efficiencies of impulse turbines are usually around80 percent. Because high head, low discharge sites are common andefficiencies are high, Pelton and Turgo wheels are easilyinstalled without the rigorous design typical of reactionturbines. Civil works are much less than those of reaction turbines

since impulse turbines are independent of pressure forces.

The speed of cross-flow turbines falls in the same range as thatof reaction turbines. Regulating the speed is achieved throughnozzle velocity control or by diverting some water around theturbine, lessening water discharge and velocity.

The advantages of impulse turbines include:

* low water discharge requirements;

* the efficient use of high heads;

* small physical size yet high power output;

* high efficiencies;

* simple design;

* simple civil works;

* low maintenance;

* low cost; and

* low labor input.

The disadvantages of impulse turbines include:

* poor power output under low heads;

* the possibility of increased wear and tear due to operationat high speed;

* very strict manufacturing specifications for other thancrossflow; and

* the complexity of regulating the speed of the turbine.

Because of their simple design and low cost, impulse turbineslend themselves well to minihydropower and microhydropower installationsin remote areas in developing countries.

Waterwheels

Of all water-power machines, waterwheels are the simplest intheory, design, and installation. In this section, four types ofwaterwheels are described: the undershot waterwheel, the Ponceletwheel, the breast wheel, and the overshot waterwheel.

The undershot waterwheel derives its power from flowing waterunder a very low head. As shown in Figure 10, water passing under

fig10p19.gif (600x600)

the wheel strikes the paddles, causing the wheel to rotate. Efficiency of the undershot waterwheel is quite low, and the headsranging from 2 to 5 meters are best.

Figure 11 shows the Poncelet wheel, which is similar in design to

fig11p19.gif (600x600)

the undershot wheel. However, unlike the flat blades of an undershotwheel, the blades of a Poncelet wheel are curved, creating amore efficient water interaction by forcing the water to back upand discharge through a narrow opening. The Poncelet wheel has aminimum diameter of 4.5 meters and operates most efficientlyunder heads of 2 meters. Because of design improvements over theundershot wheel, efficiencies are slightly higher. A breastworkof concrete fitted close to the paddles keeps the water backed upbut necessitates trash removal (trash racks) to ensure thatbranches or rocks will not enter the system.

The breast wheel shown in Figure 12 is another improvement over

fig12p20.gif (600x600)

the undershot wheel. This wheel, like the Poncelet wheel, backsup the water and use the energy created therein. A close-fittingbreastwork forces the water into the blades to produce torque.Efficiencies approach 65 percent for high breast wheels (waterentering below the center line). The fact that breast wheels needa close-fitting breastwork, a curved bucket design, and a trashrack usually makes other types of waterwheels more attractive.

Figure 13 shows an overshot waterwheel. This design allows water

fig13p20.gif (600x600)

to enter buckets at the highest point, and the weight of thewater causes the wheel to turn. Water discharge is controlled bya sluice gate to minimize waste through overfilled buckets. Overshotwheels are the most efficient waterwheels and can operateunder heads of 3 meters and above.

Waterwheels are easy to build. They are usually large and rotatevery slowly, usually in the range of 3 to 20 rpm. Waterwheelsproduce high torque and can be used in nonconventional ways.

The advantages of waterwheels include:

* simple design;

* easy construction;

* high torque;

* operation under large flow variations;

* minimal maintenance and repair: and

* low cost.

The disadvantages of waterwheels include:

* low efficiencies;

* need at times for close tolerances in construction;

* slow speed; and

* large size.

Waterwheels find their niche where high torque and low speed arenecessary. In developing countries, the economics of construction, the level of technology, and the wide range of uses ensurewaterwheels a future in water-power development.

None of the machines discussed above should be applied, however,if no practical, efficient use can be found.

USES OF HYDROPOWER

The use of waterpower falls under two general categories:mechanical and electrical use. Mechanical use implies obtainingpower directly from the turbine or waterwheel and using it toaccomplish physical work. Electrical use implies the generationof electricity from the turbine or waterwheel and using it toperform work.

Mechanical Use of Hydropower

Although turbines are used to produce mechanical power, they arerarely applied that way. In Third World installations, impulsewheels are used through gearing mechanisms for grinding, threshing,or cutting. These applications are appropriate to eachsituation. Various applications of impulse turbines include:machines that thresh, grind, and cut grain; sawmill equipment,and metalworking tools. Usually drivebelts deliver power to allof this equipment while reducing speed and increasing torque.

Waterwheels lend themselves ideally to mechanical use. The foregoingapplications apply as well to waterwheels and sometimeseven more so. Milling and grinding are especially conducive towaterwheels where slow rotation is necessary. Waterwheels alsolend themselves well to the pumping of water or other liquidssince pumps require slower speeds.

Electrical Use of Hydropower

Electrical power generation requires constant speed under varyingloads. Generators operate at certain speeds, depending uponconstruction and electrical requirements. Uniform speed is very

important and usually quite fast. Impulse and reaction turbinesare used almost exclusively for electrical power generation inthe United States and Europe. In the Third World, electricalpower generation is becoming economical, and the use of turbinesis increasing. Impulse turbines can be connected directly to agenerator, but a speed regulation device must be used in combinationwith these turbines in order for the generator to work.Reaction turbines are usually connected to generators through agearbox. The regulation of speed is also important in reactionturbines and can become very complex, depending upon the reactionturbine chosen.

Waterwheels do not lend themselves well to electrical power generationdue to their slow speed and speed-governing problems inherentin their design. Thus, electrical power generation is notrecommended with waterwheels.

COST/ECONOMICS OF HYDROPOWER

Economics dictates the feasibility of hydropower installationeven if all other factors are positive. Two principal economiccharacteristics of hydropower are high initial costs and lowoperating costs. In general, a hydropower system requires substantialinitial capital investments to minimize operating costs.However, there is a point where excessively high capital costswill create the reverse effect of much higher operating costs.

To reduce initial costs, several cost-cutting steps can be taken:

* maintain low administrative costs;

* use local labor;

* use local materials as much as possible;

* build some of the equipment locally;

* design an appropriate hydropower system (i.e., one thatdoes not require high system efficiency, installation ofa governor--a device used for maintaining uniform speedin a turbine, or recruitment of a full-time staff);

* do not provide for a profit margin included in mostcostings for microhydropower installations; and

* minimize use of costly technical expertise and supervision.

It is important to note that the steps outlined above are aimedat Third World situations and represent actual experience.

Methods for determining hydropower installation costs aredifficult in Third World development situations. Nevertheless,Figure 14 gives a general idea of the relative costs of hydropower

fig14p24.gif (600x600)

in the United States. Notice that low head, low-power installationshave installed costs less than high head, high-powerinstallations. However, notice that the cost decreases as headincreases and that medium head and power output installations arethe least expensive. Figure 14 shows relative costs and thusdescribes, for all situations, the optimum head to power ratio.Figure 14 does not factor in the cost-cutting steps listed above,however. But by taking these steps, even low head and low-powersites become economical.

Relative project costs are outlined in Figure 15. Two options are

fig15p26.gif (600x600)

presented. The first option describes development situations inthe Third World. The second option describes situations applicableto developed countries. From these two options, one candeduce that the majority of costs apply to mechanical and electricalelements and could probably be reduced by following thesteps outlined previously.

This discussion demonstrates that although financial economicsare important in considering hydropower installation, there aremethods of reducing the financial impact to an acceptable level.

IV. COMPARING THE ALTERNATIVES

Hydropower, as previously discussed, is used primarily for electricaland motive power generation. Waterwheels are best usedfor motive power by direct coupling to machinery. Turbines(reaction or impulse) are best used for electrical power operation

but are being used successfully for motive power as well. Atthis point, the question arises: "Is hydropower best for mysituation, or should I use an alternate power source?" This is animportant question to consider and to answer as clearly as possible.While hydropower serves some situations very well, it maybe marginal or totally inappropriate for others. To determinewhen hydropower should be used as opposed to other alternatives,some discussion of these alternatives is necessary.

With the advent of technology transfer from technology centers inEurope and North America to developing countries, several energysources have been perfected and successfully implemented withoutthe supporting technology base. This has provided alternativeenergy sources for developing countries without the delay oftechnology development. Hence, solar power either through direct(photovoltaics) or indirect (steam production) methods, windpower, methane power, and alternative liquid fuel production (toname just a few) have become successful power producers in theirown right. These may also become candidates for considerationalong with hydropower for a particular situation. To best discusshydropower and the alternatives, several alternative energysources are summarized and then compared to hydropower.

SOLAR POWER

The sun provides a vast amount of energy to the earth each day.Depending upon climatic and atmospheric conditions, this energymay be harnessed and utilized. Two methods are popular (but notexclusive): photovoltaics and thermal. Photovoltaics employsilicon wafers or discs that produce electrical current in thepresence of light (not necessarily restricted to visible light).When many wafers are connected together, the electricity producedmay be used to power electrical machinery, electric lamps, orcharge batteries. This power is in the form of direct current(DC), however, which is usually not compatible with the alternatingcurrent (AC) produced by regional electric grid systems.Thus, to power common household appliances that use AC motors,conversion from DC to AC is necessary with great losses in energy.This implies either large expenditures to produce inefficientpower, or DC-compatible equipment which may be difficult toobtain.

The major drawback of photovoltaics is cost. The cost of producingsilicon wafers (you have to "grow" them) is still high,despite the fact that it continues to decline steadily. Purchaseof a water pump producing not more than 500 liters per minute andpowered exclusively by photovoltaics would cost U.S. $7,000.00 inKenya. This is prohibitively expensive for small communities.

Solar power may also be used to heat liquids or solids that thentransport heat. Steam may be produced through intense concentrationsof solar energy. This steam may be used to power a turbine(as in hydropower but with steam) for electricity or motiveforce. Thermal power, as created by solar energy, may also beused to heat water for domestic purposes, heat thermal masses forheat storage (passive solar heating), or even to vaporize gasesas in the Minto Wheel to produce motive force.

Solar energy conversion--either by photovoltaics or thermal--maybe a viable alternative to hydropower if the following conditionsprevail: lack of flowing water, remoteness of site, cost, technologyavailability, and end use (what is the intended goal).Although solar energy can produce electrical power (DC) withoutthe need for civil works, reservoirs, or expensive turbines andgenerators, photovoltaics are nevertheless expensive. Moreover,in some areas of the world, solar power is not suitable. InDarjeeling, India, for example, hydropower may be the best choicesimply because of lack of sunshine during the monsoon months.Over a period of four months, the sun will not shine (except forabout two weeks) because of dense cloud cover. Since powerproduction by photovoltaics is a function of solar intensity, ahuge and expensive array of solar cells would be necessary. Itwould in fact be prohibitively expensive. Thus, if the climaticconditions are not favorable, solar power as an alternative tohydropower must be ruled out.

WIND POWER

There is great power in the winds. The technological problem isto extract the power efficiently and without great expense.Windmills are the most popular form of power production by wind.Unfortunately, there are many designs available that claim bestefficiency. Efficiency refers here to the ratio of energyproduced to energy available. Available energy in the wind isgreat but energy produced by windmills (even the mosttechnologically advanced) is not more than 30 percent. Fordevelopment situations where high technology is scarce, typicalefficiencies are less than 15 percent. This means that 85percent of the available power has not been extracted.

As with solar power, wind power is dependent upon several factors.The most important is wind. Wind is not always available.Some developing countries are not suited for windmills simplybecause there is not enough wind (wind speed). Before any considerationof wind power may be entertained, data either fromweather stations or from local histories must be obtained. Ifthe average wind speed is less than about 10 km per hour, windpower will not be viable. Making effective use of wind power asan alternative to hydropower depends on the amount of wind available,availability of construction materials, expertise, and enduse.

Wind power, like solar power, can become expensive when it isneeded to provide large amounts of power. Wind power is bestsuited for motive power in pumping or turning machinery. Electricalgeneration by wind power is probably not viable withoutexpensive towers, blades, governers, alternators, and batteries.This comparison to hydropower may, in situations where hydropowercan be implemented, indicate that hydropower is the best choice.

METHANE

Methane gas is produced easily through fermentation of animal,crop, and human waste. By anaerobic (absence of oxygen) digestion

in large containers, methane gas can be produced and used forheating, lighting, or powering internal combustion engines. Thistechnology is rather simple but construction may be expensive andit is somewhat labor intensive.

Methane production is viable only where there are sufficientamounts of the right kind of waste. Vegetable matter (includingcrop residues) may be used in the digestion process but may notproduce much methane due to the large cellulose content. Thebest waste is animal waste, which, when digested at high temperatures(about 55[degrees]C), will produce great amounts of methane. Toprovide this elevated temperature, all the methane produced mayhave to be used unless there is some other inexpensive heatsource for this. Storage and transport of methane gas may bedifficult and expensive. As an alternative to hydropower,methane may be the closest to actual compatibility of uses. Itcan replace hydropower for electrical generation and motive powerby powering internal combustion engines. One problem with methaneas a fuel is the high carbon dioxide, sulfur (hydrogen sulfide),and water content. All these chemicals have adverse side effectson engines when used in amounts such as those that come directlyfrom the digester. Thus, cleaning or "scrubbing" the gas as itemerges from the digester is necessary before injection into anengine. This adds to the expense of the digester.

Both methane generation and hydropower require high capital costsbut are relatively low in operating costs. Operator expertise isnecessary for both, also. In sum, methane, as generated byanaerobic digestion of plant and animal wastes, presents a veryviable alternative to hydropower where the necessary resourcesare present. Capital costs are probably lower for methane butoperating costs will almost invariably be higher than those forhydropower.

LIQUID FUELS FOR INTERNAL COMBUSTION ENGINERS

The two popular fuels for internal combusion engines are gasoline(petrol) and diesel. In many parts of the world, these fuels arevery difficult to obtain and are usually very expensive. Internalcombustion engines are prevalent throughout the world. Ifother fuels can be developed to replace the expensive fossilfuels such as gasoline and diesel, they would then present viablealternatives to hydropower.

Several fuels are already in use. They include: methane (discussedpreviously), butane, propane, sunflower oil, and peanutoil. While there may be other possibilities, these represent themost common at this time. Butane and propane are gases which arenormally used for heating or lighting. They contain high amountsof energy but are not always available, especially in remoteareas. They can also be expensive to purchase and transport.Sunflower and peanut oils are just now becoming popular fordiesel engines. They contain high amounts of energy but if notpurified extensively, will cause contamination and subsequentdestruction of the engine. None of these alternate fuels containsas high an energy content per unit volume as gasoline or diesel.Thus, more must be used to obtain the same output from an engine.

Butane and propane are usually obtained from underground deposits(along with crude oil) and thus are not available worldwide.Methane, as discussed above, can be produced locally and with lowtechnology. Sunflower and peanut oils can also be producedlocally but require expensive pressing and purification processesbefore they can be used. If economics allow use of alternativeinternal combustion fuels to produce electricity and motive power,they present good alternatives to hydropower.

This description of alternatives to hydropower is not meant to beexhaustive or complete. If hydropower is a possibility for aparticular situation, consideration of other alternatives isnecessary from an economic, social, and end use perspective. Bycomparing the alternatives presented above, one can begin todetermine whether or not hydropower is the best choice. However,it is very important to consider hydropower alternatives in moredepth than given above. This is a technological discussion butthe importance of social and cultural considerations is just asimportant, if not more so. Keep in mind, however, that hydropoweris a very efficient, clean source of energy and should beseriously considered in light of the alternatives for a particularsituation.

V. CHOOSING THE TECHNOLOGY RIGHT FOR YOU

Site selection, flow diversions, and environmental effects areamong the important factors that must be considered before hydropowerinstallation begins. The proper sequence of events must beadhered to for installation to be successful.

Economics strongly dictates the size of the hydropower site.Small hydropower sites become less economical due to the nonlinearityof costs and benefits. As the size increases, thebenefit-cost ratio increases, providing more desirable outcomes.This is unfortunate, and many small installations, while seeminglyideal, are not implemented for this reason. Much has beendone, however, to offset these negative economic indicators.Hydropower development in Pakistan, for example, has been encouragedthrough the "Small Decentralized Hydropower (SDH) program"(Inversin, 1981). This program assists in very small (micro)hydropower development and has been successful because the followingobjectives were met:

* readily available materials were used in nonconventionalways;

* hydropower designs were suited to the local realities;and

* the community was involved in the initiation, implementation,management, operation, and maintenance of the hydropowerschemes.

Thus, small, decentralized hydropower in development situationsis clearly feasible. Due to transportation, material and financialdifficulties of larger hydropower installations, small-scalehydropower installations are very desirable. However, as stated

previously, steps to develop hydropower on any scale must betaken carefully and in sequence.

Information on the availability of power must be obtained beforeany other steps are taken. Information on elevation differences,amounts of water available, and construction feasibility alsomust be obtained. Important preliminary questions to be answeredinclude:

1. How much rainfall occurs over a year's time and how isit distributed throughout the year?

2. What type of water fall is available or must it be artificiallyinduced?

3. How much water is available for use?

4. What is the topography of the area under considerationand how can it best be used?

5. Is the community willing to participate in such a project?

6. What type of community education is necessary and howwill it be implemented?

If positive answers to these six questions can be obtained,subsequent steps can then be taken.

Financing also must be obtained. This can be difficult in ThirdWorld development situations where few grants or loans are availableand where communities are not able to raise money themselves.If financing is unavailable, the project cannot be implemented.No hydropower project is free.

Environmental concerns are very important especially when majorflow diversion or retention is required. Studies addressing thelong-term effects of a hydropower project must be done. If thesestudies show that the environmental effects are minimal (therewill always be some), the project can continue. If, on the otherhand, the environmental effects are negative, reconsideration isnecessary with the possibility of project termination.

If permits must be obtained, that must be done long before anydesign or construction is initiated.

Financial returns must be negotiated and benefits must be tabulatedto ensure continuing installation viability.

Once the above steps are taken, design of the physical layout canbegin. After exhaustive designs are completed, construction canbegin. When the project is completed, the hydropower system mustundergo rigorous testing. If the results of the tests are positive,operation of the hydropower system can begin.

VI. SUMMARY

Barnessing the energy from falling water is a relatively easytechnology compared to internal combusion engines. By applyingthe methods described in this paper, abundant and clean power canbe appropriately obtained.

BIBLIOGRAPHY

Alward, R.; Eisenbart, S.; and Volkman, J. Micro-hydropower:Reviewing an Old Concept. Butte, Montana: The NationalCenter for Appropriate Technology, 1979.

Arndt, R.E.A.; Farell, C.; and Wetzel, J.M. "Hydraulic Turbines."Paper presented at the Small Scale Hydropower FeasibilityStudies Seminar of the University of Minnesota, Minneapolis,Minnesota, 26-30 July, 1981.

Arndt, R.E.A.; Farell, C.; and Wetzel, J.M. "Hydraulic Turbines."In Small and Mini Hydropower Systems, pp. 6.1-6.64. Editedby Jack J. Fritz. New York: McGraw Hill, 1984.

Breslin, W.R. Small Michell (Banki) Turbine: A ConstructionManual. Arlington, Virginia: Volunteers in Technical Assistance,1980.

Deudney, Daniel. "Rivers of Energy: The Hydropower Potential."Worldwatch Paper 44. Washington, D.C.: The Worldwatch Institute,June 1981.

Durali, M. Design of Small Water Turbines for Farms and SmallCommunities. Prepared for the Office of Science and Technology,United States Agency for International Developmentby the Technology Adaptation Program, Massachusetts Instituteof Technology, Cambridge, Massachusetts, 1976.

Fraenkel, P. The Power Guide: A Catalogue of Small Scale PowerEquipment. New York: Charles Scribner's Sons, 1979.

Fritz, Jack J., ed. Small and Mini Hydropower Systems. New York:McGraw Hill, 1984.

Hamm, H.W. Low Cost Development of Small Water Power Sites.Arlington, Virginia: Volunteers in Technical Assistance,1967.

Inversin, A.R. A Case Study: Micro-hydropower Schemes in Pakistan.Washington, D.C.: National Rural Electric CooperativeAssociation, 1981.

McGuigan, D. Harnessing Water Power for Home Energy. Charlotte,Vermont: Garden Way Publishing Company, 1978.

Ovens, W.G. A Design Manual for Water Wheels. Arlington, Virginia:Volunteers in Technical Assistance, 1975.

Sorumsand Verksted A/S Company. Mini Hydro Turbines. Sorumsand,Norway: Sorumsand Verksted A/S Company, 1981.

Tudor Engineering Company. Reconnaissance Evaluation of SmallLow-Head Hydroelectric Installations. Washington, D.C.: U.S.Department of the Interior, Water and Power Resources, Engineeringand Research Center, 1980.

Volunteers in Technical Assistance. Overshot Waterwheel: Designand Construction Manual. Arlington, Virginia: Volunteersin Technical Assistance, 1979.

SUGGESTED READING LIST

Microhydropower Handbook Volume I and II. Available from U.S.Department of Commerce, National Technical Information Service,5285 Port Royal Road, Springfield, Virginia 22161 at U.S. $32.50for Volume 1 (DE83-006-697) and $31.00 for Volume II (DE83-006-698).Written for persons who want to design their own site forproducing electricity of under 100 kilowatts output. With over800 pages (both volumes included), this is probably the mostcomprehensive work on the subject.

Harnessing Water Power for Home Energy, by Dermat McGuigan. Thisbook, published by Garden Way Publishing, gives examples ofmicrohydroelectric projects from all over the world. It is agood introduction to hydropower. Priced in most book stores atunder U.S. $8.00.

Micro-Hydro Power: Reviewing an Old Concept, by the NationalCenter for Appropriate Technology, P.O. Box 3838, Butte, Montana59702-3838. This publication provides a good overview ofmicrohydropower for a moderate price (less than U.S. $5.00).

Guide to Development of Small Hydroelectric and MicrohydroelectricProjects in North Carolina, by John Warren and Paul Gallimore.This handbook on hydropower is available from the NorthCarolina Alternative Energy Corporation, Research Triangle Park,North Carolina 27709.

More Other Homes and Garbage: Designs for Self-Sufficient Living.Published by the Sierra Club. Pages 75-92 deal with producingelectricity from a stream. This book, like all of the otherbooks listed above, includes techniques for measuring head andstream flow.

Homemade Electricity: An Introduction to Small-Scale Wind, Hydro,and Photovoltaic Systems. Available from Superintendent of Documents,U.S. Government Printing Office, Washington, D.C. 20402.

Directory of Manufacturers of Small Hydropower Equipment, byAllen R. Inversin. Available from the Small Decentralized Hydropower(SDH) Program, International Programs Division of the NationalRural Electric Cooperative Association, 1800 MassachusettsAvenue N.W., Washington, D.C. 20036.

ORGANIZATIONS TO CONTACT FOR ASSISTANCE

DEVELOPMENT ORGANIZATIONS

The National Center for Appropriate TechnologyP.O. Box 3838Butte, Montana 59701 USA

Volunteers in Technical AssistanceSuite 2001815 North Lynn StreetArlington, Virginia 22209 USA

ARCHITECTS/ENGINEERS, CONSULTANTS, AND CONSTRUCTION FIRMS

The following are design firms, consultants, and contractors withexpressed interest in hydropower development. This listencompasses a spectrum ranging from small consultant firms withminimal hydropower experience to large engineering firms that canmanage a project from conception through construction. Apotential user of the services of any of the firms listed shouldsatisfy himself that the firm has the capability and experiencerequired for the service desired.

U.S. Firms

Edward A. Abdun-nurConsulting Engineer3067 South Dexter WayDenver, CO 80222 USA(303) 756-7226

Acres AmericanLiberty Bank BuildingMain at CourtBuffalo, NY 14202 USA(716) 853-7525

Allen & Boshall, Inc.Engineers-Architects-ConsultantsAttn: W. Lewis Wood, Jr.P.O. Box 12788Memphis, TN 38112 USA(901) 327-8222

Anderson-Nichols661 Harbour Way SouthRichmond, CA 94804 USA(415) 237-5490

Applied Energy Planners, Inc.Attn: E. Fletcher Christiansen, Pres.P.O. Box 88461Atlanta, GA 30338 USA(404) 451-8526

Appropriate Technologies, Inc.Attn: George L. SmithP.O. Box 1016Idaho Falls, ID 83401 USA(208) 529-1611

Associated Consultants, Inc.Attn: R.E. Palmquist3131 Fernbrook Lane NorthMinneapolis, MN 55441 USA(612) 559-5511

Auslam & Associates, Inc.Economic ConsultantsAttn: Margaret S. Hall601 University AvenueSacramento, CA 95825 USA

Ayres, Lewis, Norris & May, Inc.3983 Research Park DriveAnn Arbor, MI 48104 USA

Banner Associates, Inc.Attn: Joseph C. LordP.C. Box 550309 South Fourth StreetLaramie, WY 82070 USA(307) 745-7366

Barber EngineeringAttn: Robert W. Ross, Project Coordinator250 South Beechwood Avenue, Suite 111Boise, ID 83709 USA(208) 376-7330

Barnes, Henry, Meisenheimer & GrendeAttn: Bruce F. Barnes4658 Gravois AvenueSt. Louis, MO 63116 USA(314) 352-8630

Barr Engineering CompanyAttn: L.W. Gubbe, Vice President6800 France Avenue SouthMinneapolis, MN 55435 USA(612) 920-0655

Beak Consultants IncorporatedEnvironmental ConsultantsAttn: Bruce Eddy, Fishery BiologistEighth Floor Loyalty Building317 S. W. AlderPortland, OR 97204 USA(503) 248-9507

Bechtel National, Inc.Attn: G.D. Coxon, Business DevelopmentRepresentative, Research EngineeringP.O. Box 3965San Francisco, CA 94119 USA

Beling Consultants, Inc.

Attn: Tom BrennanBeling Building1001-16th StreetMoline, IL 61265 USA(309) 757-9800

Benham-Holway PowergroupSouthland Financial Center4111 South DarlingtonTulsa, OK 74135 USA(918) 663-7622

Berger AssociatesAttn: Richard H. MillerP.O. Box 1943Harrisburg, PA 17105 USA(717) 763-7391

Bingham EngineeringAttn: Jay R. Bingham, President165 Wright Brothers DriveSalt Lake City, UT 84116 USA(801) 532-2520

Black & VeatchAttn: P.J. Adams, PartnerActing Head of Power DivisionP.O. Box 8405Kansas City, MO 64114 USA(913) 967-2000

Boeing Engineering & ConstructionP.O. Box 3707Seattle, WA 98124 USA(206) 773-8891

Booker Associates, Inc.Attn: Franklin P. Eppert, Vice President1139 Olive StreetSt. Louis, MO 63101 USA(314) 421-1476

Bookman-Edmonston EngineeringAttn: Edmond R. Bates, P.E.600 Security Building102 North Brand BoulevardGlendale, CA 91203 USA(213) 245-1883

Booz, Allen & Hamilton, Inc.4330 East-West HighwayBethesda, MD 20814 USA(301) 951-2200

Bovey Engineers, Inc.Attn: George WallaceEast 808 Sprague Avenue

Spokane, WA 99202 USA(509) 838-4111

Boyle Engineering CorporationAttn: D.C. Schroeder1501 Quail StreetP.O. Box 3030Newport Beach, CA 92663 USA(714) 752-0505

Brown & Root, Inc.Attn: C.W. Weber, Vice-President4100 Clinton DriveP.O. Box 3Houston, TX 77001 USA(713) 678-9009

Burgess & Niple, Ltd.5085 Reed RoadColumbus, OH 43220 USA(614) 459-2050

Burns & McDonnellEngineers-Architects-ConsultantsAttn: J.C. HoffmanP.O. Box 173Kansas City, MO 64141 USA(816) 333-4375

Burns & Roe, Inc.550 Kinderkamack RoadOradell, NJ 07649 USA(212) 563-7700

Lee CarterRegistered Professional Engineer622 Belson CourtKirkwood, MO 63122 USA(314) 821-4091

C.E. Maguire, Inc.Attn: K. Peter Devenis, Senior Vice President60 First AvenueWaltham, MA 02254 USA(617) 890-0100

C.H. Guernsey & CompanyConsulting Engineers & ArchitectsAttn: W.E. PackNational Foundation West Building3555 N.W. 58th StreetOklahoma City, OK 73112 USA(405) 947-5515

C.T. Male Associates, P.C.3000 Tracy Road

Schenectady, NY 12309 USA(518) 785-0976

CH2M Hill, Inc.Attn: R.W. Gillette, Director of Power Generation1500 114th Avenue, S.E.Bellevue, WA 98004 USA(206) 453-5000

Center 4 EngineeringAttn: Gale C. Corson, P.E.523 South 7th Street, Suite AP.O. Drawer ARedmond, OR 97756 USA(503) 548-8185Chas. T. Main, Inc.Attn: R.W. Kwiatkowski, Vice PresidentSoutheast TowerPrudential CenterBoston, MA 02199 USA(617) 262-3200

Chasm Hydro, Inc.Attn: John Dowd, PresidentBox 266Chateaugay, NY 12920 USA(518) 483-7701

Childs & AssociatesAttn: Thomas R. Childs1317 CommercialBillingham, WA 98225 USA(206) 671-0107

Clark-McGlennon Associates, Inc.Attn: Peter Gardiner148 State StreetBoston, MA 02109 USA(617) 742-1580

Cleverdon, Varney & Pike, Inc.Attn: Thomas N. St. Louis126 High StreetBoston, MA 02110 USA(617) 542-0438

Clinton-Anderson Engineering, Inc.Attn: Carl V. Anderson13616 Gamma Road, Suite 101Dallas, TX 75234 USA(214) 386-9191

Converse, Ward, Davis, Dixon, Inc.Geotechnical ConsultantsAttn: Kenneth B. King, Principal EngineerThe Folger Building, Suite A101 Howard Street

San Francisco, CA 94105 USA(415) 543-7273

Crawford, Murphy & Tilly, Inc.Attn: Robert D. Wire2750 West Washington StreetSpringfield, IL 62702 USA(217) 787-8050

Cullinan Engineering Co., Inc.Attn: William S. ParkerP.O. Box 191200 Auburn StreetAuburn, MA 01501 USA(617) 832-5811

Curran Associates, Inc.Attn: R.G. Curran, President182 Main StreetNorthampton, MA 01060 USA(413) 584-7701

Dames & Moore445 South Figueroa Street, Suite 3500Los Angeles, CA 90071 USA(213) 683-1560

Daverman & Associates, P.C.Architects-EngineersAttn: Gary C. Knapp500 South SalinaSyracuse, NY 13202 USA(315) 471-2181

Davis Constructors & Engineers, Inc.P.O. Box 4-2360Anchorage, AK 99509 USA(907) 344-0571

Dhillon Engineers, Inc.Consulting Electrical EngineersAttn: B.S. Dhillon, President1600 S.W. 4th Avenue, Suite 603Portland, OR 97201 USA(503) 228-2877

DMJM HiltonAttn: R.W. Baunach, P.E.Suite 1111421 S.W. 6th AvenuePortland, OR 97204 USA(503) 222-3621

Donohue & Associates, Inc.Engineers and ArchitectsAttn: Stuart C. Walesh, Resources Engineering DepartmentMilwaukee Division

600 Larry CourtWaukesha, WI 53186 USA(414) 784-9200

Dravo Engineers and ConstructorsAttn: S. T. Maitland, Project ManagerOne Oliver PlazaPittsburgh, PA 15222 USA(412) 566-3000

DuBois & King, Inc.Engineering & Environment ServicesAttn: Maxine C. NealRoute 66Randolph, VT 05060 USA(802) 728-3376

Ebasco Services, Inc.Attn: R.E. Kessel, Manager of Proposal Development2 Reactor StreetNew York, NY 10006 USA

Edward C. Jordan CompanyAttn: E.C. Jurick, Client RelationsP.O. Box 7050, Downtown StationPortland, ME 04112 USA(207) 775-5401

Eicher Associates, Inc.Ecological & Environmental Consultants8787 S.W. Becker DrivePortland, OR 97223 USA(503) 246-9709

Electrak IncorporatedAttn: R.M. Avery6525 Belcrest Road, Suite 209Hyattsville, Maryland 20782 USA(301) 779-6868

Electrowatt Engineering ServicesAttn: U.M. Buettner1015 18th Street, N.W., Suite 1100Washington, D.C. 20036 USA(202) 659-9553

Emery & Porter, Inc.Attn: D.B. Emery, President3750 Wood StreetLansing, MI 48906 USA(517) 487-3789

Energy Research & Applications, Inc.1301 East El Segundo BoulevardEl Segundo, CA 90245 USA(213) 322-9302

Energy Services, Inc.Attn: Dr. Jay F. KunzeTwo Airport Plaza, Skyline DriveIdaho Falls, ID 83401 USA(208) 529-3064

Energy Systems CorporationAttn: K.E. Mayo, President23 Temple StreetNashua, NH 03060 USA(603) 882-0670

Engineering & Design AssociatesAttn: Stanley D. ReedSenior Principal6900 Southwest Haines RoadTigard, OR 97223 USA(503) 639-8215

Engineering Hydraulics, Inc.Attn: Glen Rockwell, President320 South Sunset StreetP.O. Box 1011Longmont, CO 80501 USA(303) 651-2373

Engineering-Science, Inc.Attn: G.S. Magnuson, Vice President125 West Huntington DriveArcadia, CA 91006 USA(213) 445-7560

Engineers Incorporated of VersontAttn: Kenneth W. Pinkham, P.E.P.O. Box 2187South Burlington, VT 05401 USA(802) 863-6389

Espey, Huston & Associates, Inc.Engineering & Environmental ConsultantsAttn: Sandra HixP.O. Box 519Austin, TX 78767 USA(512) 327-6847

Exe Associates - Consulting EngineersAttn: David A. Exe428 Park AvenueP.O. Box 1725Idahol Falls, ID 83401 USA(208) 529-0491

F.A. Villela & Associates, Inc.Civil EngineersAttn: Frank A. Villela, President308 Walker Avenue SouthWayzata, MN 55391 USA

(612) 475-0848

Fay, Spofford & Thorndike, Inc.Attn: B. Campbell, Vice PresidentOne Beacon StreetBoston, MA 02108 USA(617) 523-8300

Fluid Energy Systems, Inc.Attn: K.T. Miller, President/Director2302 32nd Street, #CSanta Monica, CA 90405 USA(213) 450-9861

Ford, Bacon & Davis Utah, Inc.Attn: B.G. Slighting375 Chipeta WayP.O. Box 8009Salt Lake City, UT 84108 USA(801) 583-3773

Foster-Miller Associates, Inc.135 Second AvenueWaltham, MA 12154 USA(617) 890-3200

Foth & Van Dyke Associates, Inc.2737 South Ridge RoadP.O. Box 3000Green Bay, WI 54303 USA

Foundation Sciences, Inc.Attn: R. Kenneth Dodds, President1630 S.W. Morrison StreetPortland, OR 97205 USA

Frederiksen, Kamine & Associates, Inc.Attn: Francis E. Borcalli, Associate1900 Point West Way, Suite 270Sacramento, CA 95815 USA(916) 922-5481

Geo Hydro Engineers, Inc.Attn: Leland D. Squier, President247 Washington AvenueMarietta, GA 30060 USA(404) 427-5050

Geothermal Surveys, Inc.99 Pasadena AvenueSouth Pasadena, CA 91030 USA(213) 255-4511

Gibbs & Hill, Inc.Attn: E.F. Kenny, DirectorPlanning & Development393 Seventh Avenue

New York, NY 10001 USA(212) 760-5279

Gilbert-CommonwealthAttn: C.A. Layland, ManagerGovernment Marketing525 Lancaster AvenueP.O. Box 1498Reading, PA 19603 USA(215) 775-2600

Hall and Associates, Inc.Attn: Ronald R. Hall, President1515 AllumbaughP.O. Box 7882Boise, ID 83707 USA(208) 377-2780

Halliwell Associates, Inc.589 Warren AvenueEast Providence, RI 02914 USA(401) 438-5020

Haner, Ross & Sporseen, Inc.Attn: J.H. Greenman15 S.E. 82nd Drive, Suite 201Gladstone, OR 97027 USA(503) 657-1384

Hansa Engineering CorporationAttn: Kurt A. Scholz, President500 Sansome StreetSan Francisco, CA 94111 USA(415) 362-9130

Harding-Lawson AssociatesP.O. Box 578Novato, CA 94948 USA(415) 892-0821

Mike HarperProfessional EngineerP.O. Box 21Peterborough, NH 03458 USA(603) 924-7757

Harrison-Western CorporationAttn: Eldon _rickle1208 Quail StreetLakewood CO 80215 USA(303) 234-0273

Harstad Associates, Inc.1319 Dexter Avenue NorthP.O. Box 9760Seattle, WA 98109 USA(206) 285-1912

Harza Engineering CompanyAttn: Leo A. Polivka,Group Management Director150 South Wacker DriveChicago, IL 60606 USA(312) 855-7000

Hoskins-Western-Sonderegger, Inc.Attn: J.M. Carpenter, Dev. Coord.825 "J" StreetP.O. Box 80358Lincoln, NE 68501 USA(402) 475-4241

Hoyle, Tanner & Associates. Inc.Attn: H.D. Hoyle, Jr., PresidentOne Technology ParkLondonderry, NH 03053 USA(603) 669-5420

Hubbell, Roth & Clark, Inc. (HRC)Environmental Consulting EngineersAttn: George Hubbell, IIP.O. Box 8242323 Franklin RoadBloomfield Hills, MI 48013 USA(313) 338-9241

Hydro Research Science3334 Victor CourtSanta Clara, CA 95050 USA(408) 988-1027

Hydrocomp201 San Antonio CircleMountain View, CA 94040 USA(415) 948-3919

Hydrogage, Inc.Attn: David C. Parsons, Hydrometric SpecialistP.O. Box 22285Tampa, FL 33623 USA(813) 876-4006

Hydrotechnic CorporationAttn: A.H. Danzberger, Vice President1250 BroadwayNew York, NY 10001 USA(212) 695-6800

International Engineering Company, Inc.180 Howard StreetSan Francisco, CA 94105 USA(415) 442-7300

J.E. Sirrine Co. of VirginiaP.O. Box 5456Greenville, SC 29606 USA(803) 298-6000

J.F. Sato and AssociatesAttn: James F. Sato, President6840 South University BoulevardLittleton, CO 80122 USA(303) 779-0667

J. Kenneth Fraser & AssociatesAttn: J.K. Fraser620 Washington AvenueRensselaer, NY 12144 USA(518) 463-4408

JBF Scientific Corporation2 Jewel DriveWilmington, MA 01887 USA(617) 657-4170

James Hansen and AssociatesAttn: James C. HansenP.O. Box 769Springfield, VT 05156 USA(802) 885-5785

James M. Montgomery, Consulting Engineers, Inc.Attn: Clifford R. Forsgren, P.E.1301 Vista AvenueBoise, ID 83705 USA(208) 345-5865

Jason M. Cortell & Associates, Inc.Environmental ConsultantsAttn: Susan R. Thomas, Marketing Coordinator244 Second AvenueWaltham, MA 02145 USA(617) 890-3737

John David Jones & Associates, Inc.Attn: Paul E. McNamee5900 Roche DriveColumbus, OH 43229 USA(614) 436-5633

Jordan/Avent & AssociatesAttn: Frederick E. Jordan, President111 New Montgomery StreetSan Francisco, CA 94105 USA(415) 989-1025

Joseph E. BonadimanAttn: J.C. BonadimanP.O. Box 5852606 East Mill Street

San Bernadino, CA 92412 USA

Kaiser Engineers, Inc.Attn: C.F. Burnap, Project Development3000 Lakeside DriveP.O. Box 23210Oakland, CA 94623 USA(415) 271-4111

Kleinschmidt & DuttingAttn: R.S. Kleinscnmidt73 Main StreetPittsfield, ME 04967 USA(207) 487-3328

Klohn Leonoff Consultants, Inc.Attn: Earl W. Speer, PresidentSuite 3443000 Youngfield StreetDenver, CO 80215 USA(303) 232-9457

Lane Construction CorporationAttn: D.E. Wittmer, Vice President-EngineeringBox 911Meriden, CT 06450 USA(203) 235-3351

Lawson-Fisher AssociatesAttn: John E. Fisher525 West Washington StreetSouth Bend, IN 46601 USA(219) 234-3167

Livingston AssociatesConsulting Geologists, P.C.Attn: C.R. Livingston4002 Green Oak DriveAtlanta, GA 30340 USA(404) 449-8571

M L B Industries, Inc.Attn: Thomas M. Eckert, Operations Manager21 Bay StreetGlen Falls, NY 12801 USA(518) 798-6814

McGoodwin, Williams & Yates, Inc.Attn: L.C. Yates, President909 Rolling Hills DriveFayetteville, AR 72701 USA(501) 443-3404

Mead & Hunt, Inc.2320 University AvenueP.O. Box 5247Madison, WI 53705 USA

(608) 233-9706

Michael Baker, Jr., Inc.Engineers & SurveyorsAttn: Wayne D. Lasch, Project Engineer4301 Dutch Ridge RoadBox 280Beaver, PA 15009 USA(412) 495-7711

Myron Anderson & AssociatesCivil ConsultantsAttn: Myron Anderson16830 N.E. 9th PlaceBellevue, WA 98008 USA(206) 747-3117

Normandeau Associates, Inc.Environmental ConsultantsAttn: Joseph C. O'Neill, Marketing Coordinator25 Nashua RoadBedford, NH 03102 USA(603) 472-5191

North American Hydro, Inc.Attn: Charles AlzbergP.O. Box 676Wautoma, WI 54982 USA(414) 293-4628

O'Brien & Gere Engineers, Inc.Justin & Courtney DivisionAttn: J.J. Williams, Vice President1617 J.F. Kennedy BoulevardSuite 1760Philadelphia, PA 19103 USA(215) 564-4282

Oscar Larson & AssociatesP.O. Box 3806Eureka, CA 95501 USA(707) 443-8381

Parsons BrinckerhoffOne Penn PlazaNew York, NY 10001 USA(212) 239-7900

Perini CorporationAttn: R.G. Simms, Vice President-Marketing73 Mt. Wayte AvenueFramingham, MA 01701 USA

Frank R. PollockConsulting Engineer6367 Verde CourtAlexandria, VA 22312 USA

(703) 256-3838

PRC Engineering Consultants, Inc.P.O. Box 3006Englewood, CO 80155 USA(303) 773-3788

Presnell Associates, Inc.Attn: David G. Presnell, Jr.200 West Broadway, Suite 804Louisville, KY 40202 USA(502) 587-9611

R.W. Beck & AssociatesAttn: Richard Lofgren200 Tower BuildingSeattle, WA 98101 USA(206) 622-5000

Radiation Management CorporationEnvironmental ConsultantsAttn: C.E. McGee, Director-Technical Marketing3508 Market StreetPhiladelphia, PA 19104 USA(215) 243-2950

Raven Systems & Research Inc.Environmental ConsultantsAttn: John Dermody, Hydrographic Engineer2200 Sixth Avenue, Suite 519Seattle, WA 98121 USA(206) 621-1126

Resource Consulting Group, Inc.Attn: Gary Goldner, Associate51 Brattle StreetCambridge, MA 02138 USA(617) 491-8315

Resource Planning Associates, Inc.Attn: A. Ashley Rooney44 Brattle StreetCambridge, MA 02138 USA(617) 661-1410

Rist-Frost AssociatesAttn: Fil Fina, Jr., Partner21 Bay StreetGlens Falls, NY 12801 USA(603) 524-4647

Robert E. Meyer ConsultantsAttn: B. Tanovan, Manager-Water Resources Department14250 S.W. Allen BoulevardBeaverton, OR 97005 USA(503) 643-7531

Ross & Baruzzini, Inc.Attn: Donald K. Ross7912 Bonhomme AvenueSt. Louis, MO 63105 USA(314) 725-2242

Russ Henke AssociatesAttn: Russ HenkeP.O. Box 106Elm Grove, WI 53122 USA(414) 782-0410

Science Applications, Inc.Attn: John A. Dracup5 Palo Alto Square, Suite 200Palo Alto, CA 94304 USA(415) 493-4326

SCS Consulting Engineers, Inc,4014 Long Beach BoulevardLong Beach, CA 90807 USA(213) 427-7437

Shawinigan Engineering CorporationAttn: James H. Cross100 Bush Street, 9th FloorSan Francisco, CA 94104 USA(415) 433-7912

Soil Systems, Inc.Attn: Robert L. Crisp, Jr.525 Webb Industrial DriveMarietta, GA 30062 USA(404) 424-6200

Southern Engineering Co. of GeorgiaAttn: J.W. CameronMain Office1000 Crescent Avenue, N.E.Atlanta, GA 30309 USA(404) 892-7171

Spooner Engineering - NorthAttn: John A. Spooner, Partner7 Fulton AvenueOshkosh, WI 54901 USA(414) 231-1188

Stanley Consultants, Inc.Stanley BuildingMuscatine, IA 52761 USA

Stone & Webster Engineering Corp.Attn: J.N. White, Vice President245 Summer StreetBoston, MA 02107 USA

Storch EngineersAttn: Herbert Storch333 East 57th StreetNew York, NY 10022 USA(212) 371-4675

STS Consultants, Ltd.Hydraulics & HydrologyAttn: Constantine N. PapadakisWolverine Tower, Suite 10143001 South State StreetAnn Arbor, MI 48104 USA(313) 663-3339

Sutherland, Ricketts & Rindahl,Consulting Engineers, Inc.Attn: Donald D. Ricketts2180 South Ivanhoe StreetDenver, CO 80222 USA(303) 759-0951

Sverdrup & Parcel Associates, Inc.Attn: D.L. Fenton, Vice President800 North 12th BoulevardSt. Louis, MO 63101 USA(314) 436-7600

System Control, Inc.Attn: W.H. Winnard1901 N. Fort Myer Drive, Suite 200Arlington, VA 22209 USA(703) 522-5770

Terrestial Environmental Specialists, Inc.R.D.1, Box 388Phoenix, NY 13135 USA(315) 695-7228

Tetra Tech, Inc.Attn: R.L. Notini, Engineer630 North Rosemead BoulevardPasadena, CA 91107 USA(213) 449-6400

The Kuljian CorporationAttn: Dr. T. Mukutmoni, Vice President-ResearchEngineering3624 Science CenterPhiladelphia, PA 19104 USA(215) 243-1972

Tippitts-Abbett-McCarthy-Stratton(TAMS), Engineers & ArchitectsAttn: Eugene O'Brien, Partner655 Third AvenueNew York, NY 10017 USA

(212) 867-1777

Tudor Engineering CompanyAttn: David C. Willer149 New Montgomery StreetSan Francisco, CA 94105 USA

Turbomachines, Inc.Attn: John W. Roda, President17342 Eastman StreetIrvine, CA 92705 USA

United Technologies Research CenterSilver LaneEast Hartford, CT 06108 USA(203) 565-4399

Veselka Enginering Consultants, Inc.Attn: A. William Veselka, P.E.325 South Mesquite StreetArlington, TX 76010 USA(817) 469-1671

W.A. Wahler & AssociatesAttn: J.L. Marzak, Vice President1023 Corporation WayP.O. Box 10023Palo Alto, CA 94303 USA(415) 968-6250

Whitman Requardt & AssociatesAttn: Henry A. Naylor, Jr.1111 North Charles StreetBaltimore, MD 21201 USA(301) 727-3450

Wilsey & Ham1035 East Hillsdale BoulevardFoster City, CA 94404 USA(415) 349-2151

Wind & Water PowerP.O. Box 49Harrisville, NH 03450 USA(603) 827-3367

Woodward-Clyde ConsultantsAttn: Joseph D. Bortano,Sr. Project Engineer3 Embarcadero Center, Suite 700San Francisco, CA 94111 USA(415) 956-7070

Richard S. WoodruffConsulting Engineer4153 Kennesaw DriveBirmingham, AL 35213 USA

(205) 879-8102

Wright, Pierce, Barnes & WymanAttn: L. Stephen Bowers, Vice President-Marketing99 Main StreetTopsham, ME 04086 USA(207) 725-8721

Non-U.S. Firms

Crippen ConsultantsAttn: R.F. Taylor, P.E.1605 Hamilton AvenueNorth Vancouver, B.C.Canada V7P 2L9(604) 985-4111

Engineering & Power Deveopment Consultants, LimitedMarlowe House, Sidcup Kent, DA15 7AUEngland(01-300 3355)

Montreal Engineering Co., Ltd.Attn: G.V. Echkenfelder, Vice PresidentP.O. Box 777, Place BonaventureMontreal, Quebec, CanadaH5A 1E3

Motor-Columbus Consulting EngineersParkstrasse 27CH-5401 Baden, Switzerland(617-875-6171)

Shawinigan Engineering CorporationSuite 31033 City Centre DriveMississanga, Ontario, CanadaL5B 2N5(416) 272-1300

Sogreath Consulting Engineers47, Avenue Marie-Reynoard38100 Grenoble, France(76) 09.80.22

SUPPLIERS/MANUFACTURERS

PRIME MOVERS

Independent Power Developers, Inc. Pelton and propeller units,Route 3, Box 285 company systemsSandpoint, ID 83864 USA

The James Leffel Company Francis/propeller/Hoppes unitsSpringfield, OH 45501

Associated Electric Company

54 Second AvenueChicopee, MA 01020 USA(Manufacturer Representative)

Gilberg, Gilkes & Gordon, Ltd. Wide range of turbines fromWestmorland, England LA9 7BZ 10 KW to multi-megawatt, Turgoand Kendal

Small Hydroelectric Systems Pelton, with power range 5P.O. Box 124 to 25 KW for heads from 50Custer, WA 98240 USA to 350 feet

Cssberger Turbinenfabrik Crossflow (Michell or BankiD-8832 Weissenberg type) turbines of 1 to 1000 KWPostfach 425Bayern, West Germany

Westward Mouldings, Ltd. Fiberglass water wheelsGreenhill Works, Delaware RoadGunnislake, Cornwall, England

Campbell Water Wheel Company Water wheels420 South 42nd StreetPhiladelphia, PA 19104 USA

Manitou Machine Works, Inc.14 Morris AvenueCold Spring, NY 10516 USA

GSA Associates Francis units223 Katonah AvenueKatonah, NY 10536 USA

Niagara Water Wheels, Ltd. Four models of propeller706 E. Main Street turbines with power in rangeWelland, Ontario L3B 3Y4, Canada of 20 to 250 KW

Barber Hydraulic Turbines, Ltd. Propeller and FrancisBarber Point, P.O. Box 340 turbinesWelland, Ontario L3B 3Y4, Canada

Canyon Industries Francis, miniature turbine5346 Mosquito Lake Road set offering 50 to 750 wattsDeming, WA 98244 USA

New Found, Inc. Small crossflow turbinesRoute 138Hope Valley, RI 02832 USA

Northern Water Power Company Axial flow propeller turbinesP.O. Box 49 with output range from 20 toHarrisville, NH 03450 USA 250 KW

Alaska Wind and Water Power Pelton turbinesP.O. Box GChigiak, AK 99567 USA

Pumps, Pipe and Power Pelton turbinesKingston VillageAustin, NE 89310 USA

Obermeyer Hydraulic Turbines Crossflow and Pelton10 Front Street turbinesCollinsville, CT 06020 USA

Leroy-Somer Siphon turbines16 Passaic AvenueFairfield, NJ 07006 USA

Belle Hydroelectric Crossflow turbines3 Leatherstocking StreetCooperstown, NY 13326 USA

Maine Hydroelectric Belfast turbinesDevelopment GroupsGoose Rocks, ME 04046 USA

Allis Chalmers Large turbinesHydro Turbine DivisionP.O. Box 712York, PA 17405 USA

MISCELLANEOUS EQUIPMENT SUPPLIERS

Windworks Gemini inverterBox 329, Route 3Mukwonago, WI 53149 USA

Lima Electric Company, Inc. AC alternator200 East Chapman RoadBox 918Lima, OH 45802

Woodward Governor Company Mechanical governor5001 N. 2nd StreetRockford, IL 61101 USA

Natural Power, Inc. GovernorNew Boston, NH 03070 USA

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