Unit 1

Energy efficiency and conservation

Our energy demand increases each year as our population and economy grow - we are

using about 2% more energy each year. Making the most of our energy efficiency

opportunities means we can reduce this growth in energy demand.

Progress to date

The latest data shows that New Zealand's energy efficiency has been improving at 0.7%

per annum over the medium term from 1995 to 2007 (this includes the transport sector

and is similar to other OECD economies).

The energy efficiency improvement has helped offset energy demand growth. About 34%

of the increased demand for energy services was met through improvements in energy

efficiency.

Nearly two thirds of the efficiency gains came from the industrial and agricultural

sectors; the balance is spread across the commercial, residential and passenger transport

sectors.

EECA's energy efficiency and conservation programs contribute to this reduction in

energy use.

Energy efficiency gains come from:

Improvements in technology

Better systems and processes

Better information

Changing behavior

Benefits from efficiency and conservation.

Energy efficiency delivers many benefits:

Overall energy costs are more affordable for businesses and families

Businesses are more productive with better international competitiveness

We have a more secure electricity system

We reduce our carbon emissions

People are healthier from living in houses that are warmer and drier

More jobs are created.

Law of conservation of energy

The nineteenth century law of conservation of energy is a law of physics. It states that

the total amount of energy in an isolated system remains constant over time. The total

energy is said to be conserved over time. For an isolated system, this law means that

energy can change its location within the system, and that it can change form within the

system, for instance chemical energy can become kinetic energy, but that energy can be

neither created nor destroyed. In the nineteenth century, mass and energy were

considered as being of quite different natures.

Since Albert Einstein's theory of special relativity showed that energy has an equivalent

mass (see mass in special relativity), and mass has an equivalent energy, one speaks of a

law of conservation of mass-energy as an updated version of the nineteenth century law.

All particles, both massive such as protons and massless such as photons, respectively

have energy and mass equivalents.

The total mass and the total energy of a system may both be respectively defined in

special relativity, but for each, its conservation law holds. Particles, both ponderable and

imponderable, are subject to inter conversions of form, in both creation and annihilation.

Nevertheless, in an isolated system, conservation of total energy and conservation of total

mass each holds as a separate law.

A consequence of the law of conservation of energy is that no intended "perpetual motion

machine" can perpetually deliver energy to its surroundings.

Energy Conservation, Alternative Fuels, Alternative Energy Strategies,

Green Buildings

Opportunities for energy conservation are increasingly available in almost every

application in any setting. Home, school, office, and industrial environments have all

benefited from cost-saving and energy-saving innovations. The advantages of energy

conservation have been quantified on the local level as tons of air-pollutants avoided and

dollars saved. Reduction in global greenhouse gas emissions are also quantified with the

benefit of reduced warming affect. Sites below provide a wealth of information useful in

the home and community, and sources for additional policy information, data on

technologies and how to order energy saving products.

On the community level opportunities for large scale energy saving applications may be

hindered by the up-front investment costs. These costs have been in many cases

subsidized through local energy utilities which have succeeded in the integration of

energy conservation into their rate base. For example, the Washington D.C. metro area,

the local utility PEPCO underwrote the cost of compact fluorescent bulbs for several

years. In other locations utilities have worked to provide interest subsidies for the

purchase of highly efficient household appliances, like refrigerators. These appliances

carry a higher purchase price, which may discourage buyers, but over the life of the

equipment will actually save money though reduce energy consumption. Subsidizing

interest payments bring the purchase price in line with conventional appliances.

Energy conservation legislation

Key Announcement

• The Government is introducing minimum energy management standards for large

energy users1 in the industry sector from FY2013. This includes i) the appointment of

energy managers, ii) reporting of energy use and iii) submission of energy efficiency

improvement plans for large energy users.

• Energy Efficiency-related legislation across various sectors will be consolidated in an

Energy Conservation Act that will be introduced in FY2013.

Objectives of Energy Conservation Act

• To help Singapore achieve the target of a 35% improvement in energy intensity by

2030, from 2005 levels.

• To improve the energy performance of companies and thus making them more

competitive in the global economy.

• To complement existing schemes and capability building programmes which provide

support for companies investing in energy efficiency.

• To ensure a co-ordinated approach to standards setting for energy efficiency across all

sectors.

Need to mandate energy management practices

• The most cost-effective way to improve energy efficiency in companies is to manage

energy use in the same rigour as how other resources such as labour and materials are

managed. Experiences of companies show that having processes and personnel in place

to ensure energy is used prudently, spot and rectify faults that result in energy wastage,

and monitor the effectiveness of EE improvement measures, can help achieve significant

cost savings. Effective energy management will also allow companies to better respond

to possible shifts in prices of energy and carbon in the future.

• In early 2009, MEWR and NEA consulted 16 large energy users from the wafer

fabrication, chemicals, electronics and pharmaceutical sectors, to better understand their

current energy management practices. The consultations surfaced a wide range of

practices.

• Mandating energy management practices will focus the companies’ attention on energy

issues, and complement existing schemes and capability building programmes which

provide support for companies investing in energy efficiency. Countries such as Japan,

Korea and Denmark already require such practices. The submission of plans will also

allow government to identify the gaps that need to be addressed, such as by reviewing

existing regulations, and enhancing existing or introducing new capability development

and financial assistance measures.

Impact of New Requirement on Industries

• The proposed mandatory energy management practices will affect companies that

consume more than 15 GWh of energy annually, or 1.29 ktoe of energy.

Need to Introduce an Energy Conservation Act

• Efforts to improve energy efficiency cuts across different sectors which are under the

authority of different government agencies. The current approach f implementing energy

efficiency requirements through a number of different Acts can be unwieldy. A new

Energy Conservation Act that consolidates all energy efficiency-related legislation in all

sectors will allow for a more co-ordinated approach to mandating energy efficiency

requirements.

• Establishing energy efficient standards across sectors under an Energy Conservation

Act will also send a strong signal to external parties that Singapore is serious in

undertaking mitigation actions to meet its international responsibilities.

Energy audit

Saving money on energy bills is attractive to businesses, industries, and individuals alike.

Customers, whose energy bills use up a large part of their income, and especially those

customers whose energy bills represent a substantial fraction of their company’s

operating costs, have a strong motivation to initiate and continue an on-going energy

cost-control program. No-cost or very low-cost operational changes can often save a

customer or an industry 10-20% on utility bills; capital cost programs with payback times

of two years or less can often save an additional 20-30%. In many cases these energy cost

control programs will also result in both reduced energy consumption and reduced

emissions of environmental pollutants.

The energy audit is one of the first tasks to be performed in the accomplishment of an

effective energy cost control program. An energy audit consists of a detailed examination

of how a facility uses energy, what the facility pays for that energy, and finally, a

recommended program for changes in operating practices or energy-consuming

equipment that will cost-effectively save dollars on energy bills. The energy audit is

sometimes called an energy survey or an energy analysis, so that it is not hampered with

the negative connotation of an audit in the sense of an IRS audit. The energy audit is a

positive experience with significant benefits to the business or individual, and the term

―audit‖ should be avoided if it clearly produces a negative image in the mind of a

particular business or individual.

An energy audit is an inspection, survey and analysis of energy flows for energy

conservation in a building, process or system to reduce the amount of energy input into

the system without negatively affecting the output.

ENERGY AUDITING SERVICES

Energy audits are performed by several different groups. Electric and gas utilities

throughout the country offer free residential energy audits. A utility’s residential energy

auditors analyze the monthly bills, inspect the construction of the dwelling unit, and

inspect all of the energy-consuming appliances in a house or an apartment. Ceiling and

wall insulation is measured, ducts are inspected, and appliances such as heaters, air

conditioners, water heaters, refrigerators, and freezers are examined, and the lighting

system is checked.

Some utilities also perform audits for their industrial and commercial customers. They

have professional engineers on their staff to perform the detailed audits needed by

companies with complex process equipment and operations. When utilities offer free or

low-cost energy audits for commercial customers, they usually only provide walk-

through audits rather than detailed audits. Even so, they generally consider lighting,

HVAC systems, water heating, insulation and some motors.

Objectives of Energy Audit

The Energy Audit provides the vital information base for overall energy conservation

program covering essentially energy utilization analysis and evaluation of energy

conservation measures. It aims at:

Identifying the quality and cost of various energy inputs.

Assessing present pattern of energy consumption in different cost centers of

operations.

Relating energy inputs and production output.

Identifying potential areas of thermal and electrical energy economy.

Highlighting wastage’s in major areas.

Fixing of energy saving potential targets for individual cost centers.

Implementation of measures for energy conservation & realization of savings.

Energy management team

All the components of a comprehensive energy management program are depicted in

Figure 2-1. These components are the organizational structure, a policy, and plans for

audits, education, reporting, and strategy. It is hoped that by understanding the

fundamentals of managing energy, the energy manager can then adapt a good working

program to the existing organizational structure. Each component is discussed in detail

below.

Organizational structure

The organizational chart for energy management shown in Figure 2-1 is generic. It must

be adapted to fit into an existing structure for each organization. For example, the

presidential block may be the general manager, and VP blocks may be division managers,

but the fundamental principles are the same. The main feature of the chart is the location

of the energy manager. This position should be high enough in the organizational

structure to have access to key players in management, and to have knowledge of current

events within the company. For example, the timing for presenting energy projects can be

critical. Funding availability and other management priorities should be known and

understood. The organizational level of the energy manager is also indicative of the

support management is willing to give to the position.

Energy Manager

One very important part of an energy management program is to have top management

support. More important, however, is the selection of the energy manager, who can

among other things secure this support. The person selected for this position should be

one with a vision of what managing energy can do for the company. Every successful

program has had this one thing in common—one person who is a shaker and mover that

makes things happen. The program is then built around this person.

There is a great tendency for the energy manager to become an energy engineer, or a

prima donna, and attempt to conduct the whole effort alone. Much has been

accomplished in the past with such individuals working alone, but for the long haul,

managing the program by involving everyone at the facility is much more productive and

permanent. Developing a working organizational structure may be the most important

thing an energy manager can do.

The role and qualifications of the energy manager have changed substantially in the past

few years, caused mostly by EPAC92 requiring certification of federal energy managers,

deregulation of the electric utility industry bringing both opportunity and uncertainty, and

by performance contracting requiring more business skills than engineering.

Requirements for an energy management are:

• Set up an Energy Management Plan

• Establish energy records

• Identify outside assistance

• Assess future energy needs

• Identify financing sources

• Make energy recommendations

• Implement recommendations

• Provide liaison for the energy commit

• Plan communication strategies

• Evaluate program effectiveness

Energy Team

The coordinators shown in Figure 2-1 represent the energy management team within one

given organizational structure, such as one company within a corporation. This group is

the core of the program. The main criteria for membership should be an indication of

interest. There should be a representative from the administrative group such as

accounting or purchasing, someone from facilities and/or maintenance, and a

representative from each major department.

This energy team of coordinators should be appointed for a specific time period, such as

one year. Rotation can then bring new people with new ideas, can provide a mechanism

for tactfully removing non-performers, and involve greater numbers of people in the

program in a meaningful way.

Coordinators should be selected to supplement skills lacking in the energy manager since,

as pointed out above, it is unrealistic to think one energy manager can have all the

qualifications outlined. So, total skills needed for the team, including the energy manager

may be defined as follows:

• Have enough technical knowledge within the group to either understand the technology

used by the organization, or be trainable in that technology.

• Have knowledge of potential new technology that may be applicable to the program.

• Have planning skills that will help establish the organizational structure, plan energy

surveys, determine educational needs, and develop a strategic energy management plan.

• Understand the economic evaluation system used by the organization, particularly

payback and life cycle cost analysis.

• Have good communication and motivational skills since energy management involves

everyone within the organization.

Energy audit instrument

The requirement for an energy audit such as identification and quantification of energy

necessitates measurements; these measurements require the use of instruments. These

instruments must be portable, durable, easy to operate and relatively inexpensive. The

parameters generally monitored during energy audit may include the following:

Basic Electrical Parameters in AC &DC systems – Voltage (V), Current (I), Power factor,

Active power (kW), apparent power (demand) (kVA), Reactive power (kVAr), Energy

consumption (kWh), Frequency (Hz), Harmonics, etc.

Parameters of importance other than electrical such as temperature & heat flow, radiation,

air and gas flow, liquid flow, revolutions per minute (RPM), air velocity, noise and

vibration, dust concentration, Total Dissolved Solids (TDS), pH, moisture content,

relative humidity, flue gas analysis – CO2, O2, CO, SOx, NOx, combustion efficiency

etc.

Key instruments for energy audit are listed below

Tape Measures

The most basic measuring device needed is the tape measure. A 25-foot tape measure l"

wide and a 100 foot tape measure are used to check the dimensions of walls, ceilings,

windows and distances between pieces of equipment for purposes such as determining

the length of a pipe for transferring waste heat from one piece of equipment to the other.

Lightmeter

One simple and useful instrument is the lightmeter which is used to measure illumination

levels in facilities. A lightmeter that reads in foot candles allows direct analysis of

lighting systems and comparison with recommended light levels specified by the

Illuminating Engineering Society. A small lightmeter that is portable and can fit into a

pocket is the most useful. Many areas in buildings and plants are still significantly over

lighted, and measuring this excess illumination then allows the auditor to recommend a

reduction in lighting levels through lamp removal programs or by replacing inefficient

lamps with high efficiency lamps that may not supply the same amount of illumination as

the old inefficient lamps.

Thermometers

Several thermometers are generally needed to measure temperatures in offices and other

worker areas, and to measure the temperature of operating equipment Knowing process

temperatures allows the auditor to determine process equipment efficiencies, and also to

identify waste heat sources for potential heat recovery programs. Inexpensive electronic

thermometers with interchangeable probes are now available to measure temperatures in

both these areas. Some common types include an immersion probe, a surface temperature

probe, and a radiation shielded probe for measuring true air temperature. Other types of

infra-red thermometers and thermographic equipment are also available. An infrared

―gun‖ is valuable for measuring temperatures of steam lines that are not readily reached

without a ladder.

Voltmeter

An inexpensive voltmeter is useful for determining operating voltages on electrical

equipment and especially useful when the nameplate has worn off of a piece of

equipment or is otherwise unreadable or missing. The most versatile instrument is a

combined volt-ohm-ammeter with a clamp-on feature for measuring currents in

conductors that are easily accessible. This type of multimeter is convenient and relatively

inexpensive. Any newly purchased voltmeter, or multimeter, should be a true RMS meter

for greatest accuracy where harmonics might be involved.

Wattmeter/Power Factor Meter

A portable hand-held wattmeter and power factor meter is very handy for determining the

power consumption and power factor of individual motors and other inductive devices.

This meter typically has a clamp-on feature which allows an easy connection to the

current-carrying conductor, and has probes for voltage connections. Any newly

purchased wattmeter or power factor meter should be a true RMS meter for greatest

accuracy where harmonics might be involved.

Combustion Analyzer

Combustion analyzers are portable devices capable of estimating the combustion

efficiency of furnaces, boilers, or other fossil fuel burning machines. Two types are

available: digital analyzers and manual combustion analysis kits. Digital combustion

analysis equipment performs the measurements and reads out in percent combustion

efficiency. These instruments are fairly complex and expensive.

The manual combustion analysis kits typically require multiple measurements including

exhaust stack: temperature, oxygen content, and carbon dioxide content. The efficiency

of the combustion process can be calculated after determining these parameters. The

manual process is lengthy and is frequently subject to human error.

Airflow Measurement Devices

Measuring air flow from heating, air conditioning or ventilating ducts, or from other

sources of air flow is one of the energy auditor’s tasks. Airflow measurement devices can

be used to identify problems with air flows, such as whether the combustion air flow into

a gas heater is correct. Typical airflow measuring devices include a velometer, an

anemometer, or an airflow hood.

Fuel Efficiency Monitor

This measures oxygen and temperature of the flue gas. Calorific values of common fuels

are fed into the microprocessor which calculates the combustion efficiency.

Pitot tube and manometer:

Air velocity in ducts can be measured using a pitot tube and inclined manometer for

further calculation of flows.

Lux meters:

Illumination levels are measured with a lux meter. It consists of a photo cell which senses

the light output, converts to electrical impulses which are calibrated as lux.

HVAC

Introduction

The mechanical heating or cooling load in a building is dependent upon the various heat

gains and losses experienced by the building including solar and internal heat gains and

heat gains or losses due to transmission through the building envelope and infiltration (or

ventilation) of outside air. The primary purpose of the heating, ventilating, and air-

conditioning (HVAC) system in a building is to regulate the dry-bulb air temperature,

humidity and air quality by adding or removing heat energy. Due to the nature of the

energy forces which play upon the building and the various types of mechanical systems

which can be used in non-residential buildings, there is very little relationship between

the heating or cooling load and the energy consumed by the HVAC system.

Human Thermal Comfort

The ultimate objective of any heating, cooling and ventilating system is typically to

maximize human thermal comfort. Due to the prevalence of simple thermostat control

systems for residential and small-scale commercial HVAC systems, it is often believed

that human thermal comfort is a function solely, or at least primarily, of air temperature.

But this is not the case.

Human thermal comfort is actually maximized by establishing a heat balance between the

occupant and his or her environment. Since the body can exchange heat energy with its

environment by conduction, convection and radiation, it is necessary to look at the factors

which affect these heat transfer processes along with the body’s ability to cool itself by

the evaporation of perspiration.

All living creatures generate heat by burning food, a process known as metabolism. Only

20 percent of food energy is converted into useful work; the remainder must be dissipated

as heat. This helps explain why we remain comfortable in an environment substantially

cooler than our internal temperature of nearly 100°F (37°C).

HVAC system type

The energy efficiency of systems used to heat and cool buildings varies widely but is

generally a function of the details of the system organization. On the most simplistic level

the amount of energy consumed is a function of the source of heating or cooling energy,

the amount of energy consumed in distribution, and whether the working fluid is

simultaneously heated and cooled. System efficiency is also highly dependent upon the

directness of control, which can sometimes overcome system inefficiency.

HVAC system types can be typically classified according to their energy efficiency as

highly efficient, moderately efficient or generally inefficient. This terminology indicates

only the comparative energy consumption of typical systems when compared to each

other. Using these terms, those system types classified as generally inefficient will result

in high energy bills for the building in which they are installed, while an equivalent

building with a system classified as highly efficient will usually have lower energy bills.

However, it is important to recognize that there is a wide range of efficiencies within

each category, and that a specific energy-efficient example of a typically inefficient

system might have lower energy bills than the least efficient example of a moderately, or

even highly efficient type of system.

Figure 10.2 shows the relative efficiency of the more commonly used types of HVAC

systems discussed below. The range of actual energy consumption for each system type is

a function of other design variables including how the system is configured and installed

in a particular building as well as how it is controlled and operated.

Energy conservation apportunity

The ultimate objective of any energy management program is the identification of energy

conservation opportunities (ECO’s) which can be implemented to produce a cost saving.

However, it is important to recognize that the fundamental purpose of an HVAC system

is to provide human thermal comfort, or the equivalent environmental conditions for

some specific process. It is therefore necessary to examine each ECO in the context of its

effect on indoor air quality, humidity and thermal comfort standards, air velocity and

ventilation requirements, and requirements for air pressurization.

Thermal Comfort, Air Quality and Airflow

It is not wise to undertake modifications of an HVAC system to improve energy

efficiency without considering the effects on thermal comfort, air quality, and airflow

requirements.

Thermal Comfort

One of the most serious errors which can be made in modifying HVAC systems is to

equate a change in dry bulb air temperature with energy conservation. It is worthwhile to

recall that dry bulb air temperature is not the most significant determinant of thermal

comfort during either the heating season or cooling season.

Since thermal comfort in the cooling season is most directly influenced by air motion

cooling energy requirements can be reduced by increasing airflow and/or air motion in

occupied spaces without decreasing dry bulb air temperature. During the heating season

thermal comfort is most strongly influenced by radiant heating. Consequently, changes

from forced-air heating to radiant heating can improve thermal comfort while decreasing

heat energy requirements.

The total energy, or enthalpy, associated with a change in environmental conditions

includes both sensible heat and latent heat. Sensible heat is the heat energy required to

increase dry bulb temperature. The heat energy associated with a change in moisture

content of air is known as latent heat. (See Figure 10.12)

Changes in HVAC system design or operation which reduce sensible heating or cooling

requirements may increase latent heating or cooling energy which off- sets any energy

conservation advantage. This is particularly true of economizer cycles (ß10.5.5). The use

of cool, but humid outside air in an economizer can actually increase energy consumption

if dehumidification requirements are increased. For this reason, the only reliable type of

economizer control is enthalpy control which prevents the economizer from operating

when latent cooling requirements exceed the savings in sensible cooling.

Air velocity and air flow

The evaluation of energy conservation opportunities often neglects previously established

requirements for air velocity and airflow. As discussed above, the volume of air supplied

and its velocity have a profound influence on human thermal comfort. ECO’s which

reduce airflow can inadvertently decrease thermal comfort. Even more important, airflow

cannot be reduced below the volume of outdoor air required by codes for ventilation.

The design of an all-air or air-water HVAC system is much more complex that just

providing a supply air duct and thermostat for each space. The completed system must be

balanced to assure adequate airflow to each space, not only to offset the thermal loads,

but also to provide the appropriate pressurization of the space.

It is a common practice for supply air to exceed return air in selected spaces to create

positive pressurization, which minimizes infiltration and prevents the intrusion of odors

and other contaminants from adjacent spaces. Similarly, negative pressurization can be

achieved by designing exhaust or return airflow to exceed supply air requirements in

order to maintain a sterile field or to force contaminants to be exhausted. Any alterations

in air supply or return requirements upset the relationship between supplies and return

airflows requiring that the system be rebalanced.

Indoor Air Quality

Another factor which is often neglected in the application of ECO’s is the effect of

system changes on indoor air quality. Indoor air quality requirements are most commonly

met with ventilation and filtration provided by an all-air or air-water HVAC system.

When outdoor air quantities are altered significantly, the effect on indoor air quality is

unknown and must be determined.

In a polluted environment, increasing outdoor air volume, for example with an

economizer cycle, either increases filtration requirements or results in a deterioration of

indoor air quality. On the other hand, reducing airflow to conditioned spaces due, for

example, to a conversion to a variable air volume system, reduces the filtration of

recycled indoor air which can likewise produce a reduction in air quality.

Cooling equipment

The most common process for producing cooling is vapor-compression refrigeration,

which essentially moves heat from a controlled environment to a warmer, uncontrolled

environment through the evaporation of a refrigerant which is driven through the

refrigeration cycle by a compressor.

Vapor compression refrigeration machines are typically classified according to the

method of operation of the compressor. Small air-to-air units most commonly employ a

reciprocating compressor which is combined with an air-cooled condenser to form a

condensing unit. This is used in conjunction with a direct-expansion (DX) evaporator coil

placed within the air-handling unit.

Cooling systems for large non-residential buildings typically employ chilled water as the

medium which transfers heat from occupied spaces to the outdoors through the use of

chillers and cooling towers.

Building envelope

Building ―Envelope‖ generally refers to those building components that enclose

conditioned spaces and through which thermal energy is transferred to or from the

outdoor environment. The thermal energy transfer rate is generally referred to as ―heat

loss‖ when we are trying to maintain an indoor temperature that is greater than the

outdoor temperature. The thermal energy transfer rate is referred to as ―heat gain‖ when

we are trying to maintain an indoor temperature that is lower than the outdoor

temperature.

Ultimately the success of any facility-wide energy management program requires an

accurate assessment of the performance of the building envelope. This is true even when

no envelope-related improvements are anticipated. Without a good understanding of how

the envelope performs, a complete understanding of the interactive relationships of

lighting and mechanical systems cannot be obtained.

In addition to a good understanding of basic principles, seasoned engineers and analysts

have become aware of additional issues that have a significant impact upon their ability

to accurately assess the performance of the building envelope.

1. The actual conditions under which products and components are installed, compared to

how they are depicted on architectural drawings.

2. The impact on performance of highly conductive elements within the building

envelope; and

3. The extent to which the energy consumption of a building is influenced by the outdoor

weather conditions, a characteristic referred to as thermal mass.

Unit 2

Demand side management

As with other developing countries the Pacific Island Countries (PICs) have experienced

significant increase in electricity demand and as a result greater emphasis is now being

placed on DSM and energy conservation activities. Most PICs are reliant on imported

fossil fuel for electricity generation and are more vulnerable to the impacts of high oil

prices. DSM offers significant benefits to PIC utilities, their customers and the PIC

economies. From a utility perspective, in addition to reducing supply costs, DSM benefits

also includes deferral of capital expenditure on generation, transmission and distribution

facilities, improved system load factor, better customer relations and better data for load

forecasting and system planning.

Utilities have several options of improving system efficiency and these are summarized

in below

Defination and rationale

Changing electricity markets in the developing and the developed countries face several

challenges, largely due to the uncertainties in the load growth, higher investments

required in capacity addition, declining fuel sources and its associated environmental

costs. Tariff changes due to the changing regulatory stands also affect the ability of

utilities to service its customer base. The concept of Demand-Side Management (DSM)

was developed in response to the potential problems of global warming and the need for

sustainable development, and the recognition that improved energy efficiency represents

the most cost-effective option to reduce the impacts of these problems.

DSM refers to cooperative activities between the utility and its customers (sometimes

with the assistance of third parties such as energy services companies and various trade

allies) to implement options for increasing the efficiency of energy utilization, with

resulting benefits to the customer, utility, and society as a whole. Benefits of the DSM

initiatives are diverse, as outlined in Table 2.1 below.

DSM Planning and Implementation

DSM programs are utility and customer specific. Figure 2.1 describes various steps

involved in implementing a DSM programme.

Step 1: Load Research

This stage in the DSM implementation will typically assess the customer base, tariff, load

profile on an hourly basis and will identify the sectors contributing to the load shape. This

step will also identify the tariff classes in the utility, current recovery from different

sectors and current subsidy offered to different sectors.

Step 2: Define Load-shape Objectives

Based on the results of the load research in the utility, DSM engineers will define the

load shape objectives for the current situation. Various load-shape objectives - Peak

Clipping (reduction in the peak demand), Valley Filling (increased demand at off-peak),

Load Shifting (demand shifting to non-peak period), and Load Building (increased

demand) are possible. These are represented in Figure 2.2.

Step 3: Assess Programme Implementation Strategies

This step will identify the end-use applications that can be potentially targeted to reduce

peak demand, specifically in sectors with higher subsidies. This step will also carry out a

detailed benefit-cost analysis for the end-users and the utilities, including analysis on

societal as well as environmental benefits.

Step 4: Implementation -Implementation stage will design the programme for specific

end-use applications, will promote the programme to the target audience through

marketing approaches such as advertising, bills and inserts, and focused group meetings

as in case of the industrial sector.

Step 5: Monitoring and Evaluation -This step will track the programme design and

implementation and will compare the same with proposed DSM goal set by the utility. A

detailed benefit-cost analysis in this case will include identifying the avoided supply cost

for the utility vis-à-vis the total programme cost for the utilities and benefits to the

participants including the reduced bills or incentives to the end-users.

Applicable DSM Programs

The UNDP Power Sector Project (1993-1996) identified nine DSM programs that would

be applicable for the Pacific Islands. The proposed programs were:

• Compact Fluorescent Lamp (CFL) Programme

• High Efficiency Fluorescent Lighting Programme

• Refrigerator Labelling and Standards Programme

• Air Conditioner Labelling and Standards Programme

• Commercial Refrigeration Equipment Maintenance Programme

• Air Conditioner Equipment Maintenance Programme

• Interruptible Rates for Large Customers

• Energy Audit Programme for Large Customers

• Air Conditioner Timer Control Programme

Based on international experience other applicable programs include:

• Municipal Water Pumping Programme

• Street-lighting Programme

• Solar Hot Water Programme

• Time-of-Use Tariffs for Industrial and Commercial customers

Why promote DSM

Various reasons are put forward for promoting or undertaking DSM. For example,DSM

may be aimed at addressing the following issues (University of Warwick,REEEP, 2005):

Cost reduction—many DSM and energy efficiency efforts have been introduced

in the context of integrated resource planning and aimed at reducing total costs of

meeting energy demand;

Environmental and social improvement—energy efficiency and DSM may be

pursued to achieve environmental and/or social goals by reducing energy use,

leading to reduced greenhouse gas emissions;

Reliability and network issues—ameliorating and/or averting problems in the

electricity network through reducing demand in ways which maintain system

reliability in the immediate term and over the longer term defer the need for

network augmentation;

Improved markets—short-term responses to electricity market conditions

(―demand response‖), particularly by reducing load during periods of high market

prices caused by reduced generation or network capacity.

An energy customer may have many reasons for selecting a certain DSM activity.

Generally these would be economic, environmental, marketing or regulatory. The above

points are expressed in a slightly different way (Satish Saini, 2004), where it is argued

that the benefits of DSM to consumers, enterprises, utilities and society can be realized

through:

� Reductions in customer energy bills;

� Reductions in the need for new power plant, transmission and distribution

networks;

� Stimulation of economic development;

� Creation of long-term jobs due to new innovations and technologies;

� Increases in the competitiveness of local enterprises;

� Reduction in air pollution;

� Reduced dependency on foreign energy sources;

� Reductions in peak power prices for electricity.

Unit 3

ABSTRACT

Shunt capacitor banks are used to improve the quality of the electrical supply and the

efficient operation of the power system. Studies show that a flat voltage profile on the

system can significantly reduce line losses. Shunt capacitor banks are relatively

inexpensive and can be easily installed anywhere on the network. The protection of shunt

capacitor bank includes: a) protection against internal bank faults and faults that occur

inside the capacitor unit; and, b) protection of the bank against system disturbances.

INTRODUCTION Shunt capacitor banks (SCB) are mainly installed to provide

capacitive reactive compensation power factor correction. The use of SCBs has increased

because they are relatively inexpensive, easy and quick to install and can be deployed

virtually anywhere in the network. Its installation has other beneficial effects on the

system such as: improvement of the voltage at the load, better voltage regulation (if they

were adequately designed), reduction of losses and reduction or postponement of

investments in transmission.

The main disadvantage of SCB is that its reactive power output is proportional to the

square of the voltage and consequently when the voltage is low and the system need them

most, they are the least efficient.

THE CAPACITOR UNIT AND BANK CONFIGURATIONS

2.1 The Capacitor Unit The capacitor unit, Fig. 1, is the building block of a shunt

capacitor bank. The capacitor unit is made up of individual capacitor elements, arranged

in parallel/ series connected groups, within a steel enclosure. The internal discharge

device is a resistor that reduces the unit residual voltage o 50V or less in 5 min. Capacitor

units are available in a variety of voltage ratings (240 V to 24940V) and sizes (2.5 kvar to

about 1000 kvar).

Capacitor unit capabilities

Relay protection of shunt capacitor banks requires some knowledge of the capabilities

and limitations of the capacitor unit and associated electrical equipment including:

individual capacitor unit, bank switching devices, fuses, voltage and current sensing

devices.

Capacitors are intended to be operated at or below their rated voltage and frequency as

they are very sensitive to these values; the reactive power generated by a capacitor is

proportional to both of them (kVar ≈ 2π f V 2). The IEEE Std 18-1992 and Std 1036-

1992 specify the standard ratings of the capacitors designed for shunt connection to ac

systems and also provide application guidelines.

These standards stipulate that:

a) Capacitor units should be capable of continuous operation up to 110% of rated

terminal rms voltage and a crest voltage not exceeding 1.2 x √2 of rated rms voltage,

including harmonics but excluding transients. The capacitor should also be able to carry

135% of nominal current.

b) Capacitors units should not give less than 100% nor more than 115% of rated reactive

power at rated sinusoidal voltage and frequency.

c) Capacitor units should be suitable for continuous operation at up to 135%of rated

reactive power caused by the combined effects of:

• Voltage in excess of the nameplate rating at fundamental frequency, but not over

110% of rated rms voltage.

• Harmonic voltages superimposed on the fundamental frequency.

• Reactive power manufacturing tolerance of up to 115% of rated reactive power.

2.2 Bank Configurations

The use of fuses for protecting the capacitor units and it location (inside the capacitor unit

on each element or outside the unit) is an important subject in the design of SCBs. They

also affect the failure mode of the capacitor unit and influence the design of the bank

protection. Depending on the application any of the following configurations are suitable

for shunt capacitor banks:

a) Externally Fused

An individual fuse, externally mounted between the capacitor unit and the capacitor bank

fuse bus, typically protects each capacitor unit. The capacitor unit can be designed for a

relatively high voltage because the external fuse is capable of interrupting a high-voltage

fault. Use of capacitors with the highest possible voltage rating will result in a capacitive

bank with the fewest number of series groups.

A failure of a capacitor element welds the foils together and short circuits the other

capacitor elements connected in parallel in the same group. The remaining capacitor

elements in the unit remain in service with a higher voltage across them than before the

failure and an increased in capacitor unit current. If a second element fails the process

repeats itself resulting in an even higher voltage for the remaining elements. Successive

failures within the same unit will make the fuse to operate, disconnecting the capacitor

unit and indicating the failed one.

Externally fused SCBs are configured using one or more series groups of parallel-

connected capacitor units per phase (Fig. 2). The available unbalance signal level

decreases as the number of series groups of capacitors is increased or as the number of

capacitor units in parallel per series group is increased. However, the kiloVar rating of

the individual capacitor unit may need to be smaller because a minimum number of

parallel units are required to allow the bank to remain in service with one fuse or unit out.

b) Internally Fused

Each capacitor element is fused inside the capacitor unit. The fuse is a simple piece of

wire enough to limit the current and encapsulated in a wrapper able to withstand the heat

produced by the arc. Upon a capacitor element failure, the fuse removes the affected

element only. The other elements, connected in parallel in the same group, remain in

service but with a slightly higher voltage across them.

Fig. 3 illustrates a typical capacitor bank utilizing internally fused capacitor units. In

general, banks employing internally fused capacitor units are configured with fewer

capacitor units in parallel and more series groups of units than are used in banks

employing externally fused capacitor units. The capacitor units are normally large

because a complete unit is not expected to fail.

c) Fuseless Shunt Capacitor Banks

The capacitor units for fuseless capacitor banks are identical to those for externally fused

described above. To form a bank, capacitor units are connected in series strings between

phase and neutral, shown in Fig. 4.

The protection is based on the capacitor elements (within the unit) failing in a shorted

mode, short- circuiting the group. When the capacitor element fails it welds and the

capacitor unit remains in service. The voltage across the failed capacitor element is then

shared among all the remaining capacitor element groups in the series. For example, is

there are 6 capacitor units in series and each unit has 8 element groups in series there is a

total of 48 element groups in series. If one capacitor element fails, the element is

shortened and the voltage on the remaining elements is 48/47 or about a 2% increase in

the voltage. The capacitor bank continues in service; however, successive failures of

elements will lead to the removal of the bank.

The fuseless design is not usually applied for system voltages less than about 34.5 kV.

The reason is that there shall be more than 10 elements in series so that the bank does not

have to be removed from service for the failure of one element because the voltage across

the remaining elements would increase by a factor of about E (E – 1), where E is the

number of elements in the string.

The discharge energy is small because no capacitor units are connected directly in

parallel. Another advantage of fuseless banks is that the unbalance protection does not

have to be delayed to coordinate with the fuses.

d) Unfused Shunt Capacitor Banks

Contrary to the fuseless configuration, where the units are connected in series, the

unfused shunt capacitor bank uses a series/parallel connection of the capacitor units. The

unfused approach would normally be used on banks below 34.5 kV, where series strings

of capacitor units are not practical, or on higher voltage banks with modest parallel

energy. This design does not require as many capacitor units in parallel as an externally

fused bank.

CAPACITOR BANK DESIGN

The protection of shunt capacitor banks requires understanding the basics of capacitor

bank design and capacitor unit connections. Shunt capacitors banks are arrangements of

series/ paralleled connected units. Capacitor units connected in paralleled make up a

group and series connected groups form a single-phase capacitor bank.

As a general rule, the minimum number of units connected in parallel is such that

isolation of one capacitor unit in a group should not cause a voltage unbalance sufficient

to place more than 110% of rated voltage on the remaining capacitors of the group.

Equally, the minimum number of series connected groups is that in which the complete

bypass of the group does not subject the others remaining in service to a permanent

overvoltage of more than 110%.

The maximum number of capacitor units that may be placed in parallel per group is

governed by a different consideration. When a capacitor bank unit fails, other capacitors

in the same parallel group contain some amount of charge. This charge will drain off as a

high frequency transient current that flows through the failed capacitor unit and its fuse.

The fuse holder and the failed capacitor unit should withstand this discharge transient.

The discharge transient from a large number of paralleled capacitors can be severe

enough to rupture the failed capacitor unit or the expulsion fuse holder, which may result

in damage to adjacent units or cause a major bus fault within the bank. To minimize the

probability of failure of the expulsion fuse holder, or rupture of the capacitor case, or

both, the standards impose a limit to the total maximum energy stored in a paralleled

connected group to 4659 kVar. In order not to violate this limit, more capacitor groups of

a lower voltage rating connected in series with fewer units in parallel per group may be a

suitable solution. However, this may reduce the sensitivity of the unbalance detection

scheme. Splitting the bank into 2 sections as a double Y may be the preferred solution

and may allow for better unbalance detection scheme. Another possibility is the use of

current limiting fuses.

The optimum connection for a SCB depends on the best utilization of the available

voltage ratings of capacitor units, fusing, and protective relaying. Virtually all substation

banks are connected wye. Distribution capacitor banks, however, may be connected wye

or delta. Some banks use an H configuration on each of the phases with a current

transformer in the connecting branch to detect the unbalance.

CAPACITOR BANK PROTECTION

The protection of SCB’s involves: a) protection of the bank against faults occurring

within the bank including those inside the capacitor unit; and, b) protection of the bank

against system disturbances and faults.

The protection selected for a capacitor bank depends on bank configuration, whether or

not the capacitor bank is grounded and the system grounding.

Capacitor Unbalance Protection

The protection of shunt capacitor banks against internal faults involves several protective

devices/ elements in a coordinated scheme. Typically, the protective elements found in a

SCB for internal faults are: individual fuses (not discuss in this paper), unbalance

protection to provide alarm/ trip and overcurrent elements for bank fault protection.

Removal of a failed capacitor element or unit by its fuse results in an increase in voltage

across the remaining elements/ units causing an unbalance within the bank. A continuous

overvoltage (above 1.1pu) on any unit shall be prevented by means of protective

relaysthat trip the bank. Unbalance protection normally senses changes associated with

the failure of a capacitor elemenor unit and removes the bank from service when the

resulting overvoltage becomes excessive on the remaining healthy capacitor units.

Unbalance protection normally provides the primary protection for arcing faults within a

capacitorbank and other abnormalities that may damage capacitor elements/ units. Arcing

faults may cause substantial damage in a small fraction of a second. The unbalance

protection should haveminimum intentional delay in order to minimize the amount of

damage to the bank in the event ofexternal arcing.

In most capacitor banks an external arc within the capacitor bank does not result in

enough change in the phase current to operate the primary fault protection (usually an

overcurrent relay)The sensitivity requirements for adequate capacitor bank protection for

this condition may be verdemanding, particularly for SBC with many series groups. The

need for sensitive resulted in the development of unbalance protection where certain

voltages or currents parameters of the capacitor bank are monitored and compared to the

bank balance conditions.

Capacitor unbalance protection is provided in many different ways, depending on the

capacitor bank arrangement and grounding. A variety of unbalance protection schemes

are used for internally fused, externally fused, fuseless, or unfused shunt capacitor.

Unit-4

MOTOR EFFICIENCY

MOTOR:- An electric motor is an electromechanical device that converts electrical

energy into mechanical energy.

EFFICIENCY:- Efficiency in general describes the extent to which time or effort is

well used for the intended task or purpose. It is often used with the specific purpose of

relaying the capability of a specific application of effort to produce a specific outcome

effectively with a minimum amount or quantity of waste, expense, or unnecessary effort.

MOTOR EFFICIENCY:-In a perfect world, AC induction motors would operate at

100% efficiency – in other words, every kilowatt of power delivered to the motor

terminals would be converted to useful work at the motor shaft. However, in the real

world this is not the case. Only a percentage of the delivered power is converted to useful

work, and that percentage will vary. The efficiency is the ratio of power delivered by the

motor at the shaft to the power delivered to the motor at the terminals.

In general, AC motors operate most efficiently at around 75% of full rated load, with the

efficiency falling off only slightly until somewhere between 25% and 50% of full load,

where the efficiency begins to drop significantly. As a rule of thumb, the larger the

motor, the flatter this curve is, and the lower the load percentage has to drop before the

efficiency starts to drop. The efficiency curve for typical AC motors is shown below:

Most electric motors are designed to run at 50% to 100% of rated load. Maximum

efficiency is usually near 75% of rated load. Thus, a 10-horsepower (hp) motor has an

acceptable load range of 5 to 10 hp; peak efficiency is at 7.5 hp. A motor’s efficiency

tends to decrease dramatically below about 50% load. However, the range of good

efficiency varies with individual motors and tends to extend over a broader range for

larger motors. A motor is considered under loaded when it is in the range where

efficiency drops significantly with decreasing load. Power factor tends to drop off

sooner, but less steeply than efficiency, as load decreases.

Overloaded motors can overheat and lose efficiency. Many motors are designed with a

service factor that allows occasional overloading. Service factor is a multiplier that

indicates how much a motor can be overloaded under ideal ambient conditions. For

example, a 10-hp motor with a 1.15 service factor can handle an 11.5-hp load for short

periods of time without incurring significant damage. Although many motors have

service factors of 1.15, running the motor continuously above rated load reduces

efficiency and motor life. Never operate overloaded when voltage is below nominal or

when cooling is impaired by altitude, high ambient temperature, or dirty motor surfaces.

If your operation uses equipment with motors that operate for extended periods under

50% load, consider making modifications. Sometimes motors are oversized because they

must accommodate peak conditions, such as when a pumping system must satisfy

occasionally high demands. Options available to meet variable loads include two-speed

motors, adjustable speed drives, and load management strategies that maintain loads

within an acceptable range.

Determining if motors are properly loaded enables to make informed decisions about

when to replace motors and which replacements to choose. Measuring motor loads is

relatively quick and easy when we use the techniques discussed. We should perform a

motor load and efficiency analysis on all of your major working motors as part of our

preventative maintenance and energy conservation program.

Recommend that survey and test all motors operating over 1000 hours per year.

Using the analysis results, divide your motors into the following categories:

• Motors that are significantly oversized and under loaded—replace with more efficient,

properly sized models at the next opportunity, such as scheduled plant downtime.

• Motors that are moderately oversized and under loaded—replace with more efficient,

properly sized models when they fail.

• Motors that are properly sized but standard efficiency—replace most of these with

energy-efficient models when they fail. The cost effectiveness of an energy-efficient

motor purchase depends on the number of hours the motor is used, the price of electricity,

and the price premium of buying an energy-efficient motor.

Determining Motor Loads

Input Power Measurements

When ―direct-read‖ power measurements are available, use them to estimate motor part-

load. With measuredparameters taken from hand-held instruments, you can use Equation

1 to calculate the three-phase input powerto the loaded motor. You can then quantify the

motor’s part-load by comparing the measured input power underload to the power

required when the motor operates at rated capacity.The relationship is shown in

Equation3.

Line Current Measurements

The current load estimation method is recommended when only amperage measurements

are available. Theamperage draw of a motor varies approximately linearly with respect

to load, down to about 50% of full load. Below the 50% load point, due to reactive

magnetizing current requirements, power factor degradesand the amperage curve

becomes increasingly non-linear. In the low load region, current measurements are not a

useful indicator of load.

The Slip Method

The slip method for estimating motor load is recommended when only operating speed

measurements are available.The synchronous speed of an induction motor depends on the

frequency of the power supply and on thenumber of poles for which the motor is wound.

The higher the frequency, the faster a motor runs. The more polesthe motor has, the

slower it runs. Table 1 indicates typical synchronous speeds

Determining Motor Efficiency

The NEMA definition of energy efficiency is the ratio of its useful power output to its

total power input and is usually expressed in percentage:-

By definition, a motor of a given rated horsepower is expected to deliver that quantity of

power in a mechanical form at the motor shaft. Figure is a graphical depiction of the

process of converting electrical energy to mechanical energy. Motor losses are the

difference between the input and output power. Once the motor efficiency has been

determined and the input power is known, you can calculate output power.

NEMA design A and B motors up to 500 hp in size are required to have a full-load

efficiency value (selected from a table of nominal efficiencies) stamped on the

nameplate. Most analyses of motor energy conservation savings assume that the existing

motor is operating at its nameplate efficiency. This assumption is reasonable above the

50% load point as motor efficiencies generally peak at around 3/4 load with performance

at 50% load almost identical to that at full load. Larger horsepower motors exhibit a

relatively flat efficiency curve down to 25% of full load.

It is more difficult to determine the efficiency of a motor that has been in service a long

time. It is not uncommon for the nameplate on the motor to be lost or painted over. In that

case, it is almost impossible to locate efficiency information. Also, if the motor has been

rewound, there is a probability that the motor efficiency has been reduced.

When nameplate efficiency is missing or unreadable, you must determine the efficiency

value at the operating load point for the motor. If available, record significant nameplate

data and contact the motor manufacturer. With the style, type, and serial number, the

manufacturer can identify approximately when the motor was manufactured. Often the

manufacturer will have historical records and can supply nominal efficiency values as a

function of load for a family of motors.

When the manufacturer cannot provide motor efficiency values, you may use estimates

from contains nominal efficiency values at full, 75%, 50%, and 25% load for typical

standard efficiency motors of various sizes and with synchronous speeds of 900, 1200,

1800, and 3600 rpm.

Three steps are used to estimate efficiency and load. First, use power, amperage, or slip

measurements to identify the load imposed on the operating motor. Second, obtain a

motor part-load efficiency value consistent with the approximated load either from the

manufacturer or by interpolating from the data supplied. Finally, if direct-read power

measurements are available, derive a revised load estimate using both the power

measurement at the motor terminals and the part-load efficiency value as shown:-

Power Factor: Instantaneous power is proportional to instantaneous voltage times

instantaneous current. AC voltage causes the current to flow in a sine wave replicating

the voltage wave.However, inductance in the motor windings somewhat delays current

flow, resulting in a phase shift. This transmits less net power than perfectly time-matched

voltage and current of the same RMS values. Power factor is the fraction of power

actually delivered in relation to the power that would be delivered by the same voltage

and current without the phase shift. Low power factor does not imply lost or wasted

power, just excess current. The energy associated with the excess current is alternately

stored in the windings’ magnetic field and regenerated back to the line with each AC

cycle. This exchange is called reactive power. Though reactive power is theoretically not

lost, the distribution system must be sized to accommodate it, which is a cost factor. To

reduce these costs, capacitors are used to ―correct‖ low power factor. Capacitors can be

thought of as electrical reservoirs to capture and reflect reactive power back to the motor.

RMS Voltage : AC voltage rises positive and falls negative 60 times per second, so how

do you state its value? Industry practice is to quote the RMS voltage. RMS is a value

70.7% of the peak positive voltage. An RMS voltage will produce exactly the same

heating rate in a resistive load as a DC voltage of the same value. RMS is the acronym

for the mathematical steps used in its derivation. Square the voltage at all moments in an

AC cycle, take the mean of these, and then take the square root of the mean. For reasons

lost in obscurity, the steps are stated in reverse sequence, Root Mean Square.

ENERGY EFFICIENT LIGHTING AND BARRIERS IN ITS

IMPLEMENTATION

Introduction: Energy management and cost reductions are key tools in strategic

planning. Energy costs now constitute a major component of operating funds. Thus,

energy conservation and efficiency improvement are key necessities for enhanced

productivity. Lighting in a typical telecom building constitutes about25% of the energy

bills. There is a considerable scope of reducing energy consumption through energy

efficient lighting schemes. However, the experience shows that there are barriers in

providing energy efficient lighting schemes due to high capital cost, lack of knowledge

and good quality products.

Measures for energy efficient and economic use of lighting: Measures

which can contribute for energy efficient and economic use of lighting are asunder:

(i) Segregation of general and task lighting.

(ii) Automatic switching On and Off of lighting by using sensors.

(iii) Maximum use of sunlight.

(iv) Light surrounding décor.

(v) Use of energy efficient lamps (HPMV, HPSV, CFL,Slimline tubes TL5 tubes

etc. etc).

(vi) Use of dimmers to reduce the intensity of artificial light as the sunlight is

used.

(vii) High efficiency luminors.

(viii) High frequency chokes.

ENERGY EFFICIENT LUMINOR:

The norms issued by the directorate specifically provides for use of 1X40watt mirror

optic fluroscent tubes fittings . It is seen that this luminor gives maximum lumens per

watt. Subsequent to the issue of norms, it is seen that M/S Asian Electronic Ltd. Have

come out with Asian E+ energy efficient tubelights, claiming reduction of about 45% in

lighting load. This tubelight can be retrofitted and also available with a optional demur

switch. These fixtures uses M/S Osram E5 lamps which has rates life of 18000 burning

hours as against 5000 burning hours for conventional fluroscent tubes.

ELECTRONIC CHOKES:

Even though it is established that high frequency electronic glass provides significant

savings in power, yet there has been a great amount of reluctance to use the same , due to

following reasons.

(i) High cost of good quality electronic

(ii) Generation of harmonics and humming sound by some of these electronic

chokes

(iii) Blowing of fuse provided in some of these chokes for protection of electronic

circuit. On experimental basis, these chokes have been used in some of the

exchanges and departmental complexes, with mixed results.

AUTOMATIC SWITCHING ON & OFF OF LIGHTING BY USING SENSORS:

In Telecom. Buildings, so far we have not used sensors for automatic switching ON &

OFF the lightings. The use of these sensors can provide substantial savings , as it is seen

that occupants of the building normally do not switch off the lighting, even when they are

away from their place of work. Similarly in some of the switch rooms, the lightings may

be ON even when nobody is working in the switch room. The movement sensors, in such

cases, can be effectively used to switch off the lighting for energy conservation. Dimmers

can also be used effectively to reduce the intesntiy of the light as the sunlight increases

during the day time.

DAYLIGHT: By suitable design of buildings / switch rooms, indirect sunlight can be

used. to provide illumination during day time, without increasing the heat load. This

has to be coordinated with the Architect. So that tailormade shafts or ducts can be

provided in abuilding to bring daylight as a source of lighting inside the building ,

thereby, minimizing need for aritificial lighting.

LIGHT SURROUNDING DÉCOR:The décor plays an important part in illumination

design. Light décor will require less lighting and thus, can contribute for energy saving.

This can be coordinated with the Architect.

USE OF ENERGY EFFICIENT LAMPS: The compact flursocent lamps instead of

incandescent lamps , in general area, will result in substantial energy conservations. The

lighting in general area inside a building is normally switched ON for maximum period

in the day and thus ,use of efficient lamps will definitely contribute in energy savings.

Similarly, slimline tubes (36watt) , and Asian E+ tube fittings with T5 lamp, can result

into substantial savings.

BARRIERS TO PROVIDE ENERGY EFFICIENT LIGHTING: The energy

efficient lighting is often a symbol for energy efficiency in general . However, it is seen

that practically there are number of barriers in providing energy efficient lighting.

(i) High capital cost- The energy efficient fixtures such as Asian E+ with T5

lamps , Electronic chokes, sensors and dimmers have high capital cost .

(ii) Lack of awareness – Some of the products which can contribute significantly

in improving lighting efficiency are not available in local markets resulting

into lack of awareness.

(iii) Availability of Quality products- There are not sufficient guarantees that

energy efficient accessories / fixtures will perform satisfactorily in the field

for their declared life. It is often seen that life of some of these products is

much less as compared to the declared life and it is a common knowledge that

electronic chokes do produce humming sound in many cases and requires

special setting for individual sets.

Light fixture

A light fixture, light fitting, or luminaire is an electrical device used to create artificial

light by use of an electric lamp. All light fixtures have a fixture body and a light socket to

hold the lamp and allow for its replacement. Fixtures may also have a switch to control

the light. Fixtures require an electrical connection to a power source; permanent lighting

may be directly wired, and moveable lamps have a plug. Light fixtures may also have

other features, such as reflectors for directing the light, an aperture (with or without a

lens), an outer shell or housing for lamp alignment and protection, and an electrical

ballast or power supply. A wide variety of special light fixtures are created for use in the

automotive lighting industry, aerospace, marine and medicine.

The use of the word "lamp" to describe light fixtures is common slang for an all-in-one

luminary unit, usually portable "fixtures" such as a table lamp or desk lamp (in contrast

to a true fixture, which is fixed in place with screws or some other semi-permanent

attachment). In technical terminology, a lamp is the light source, what is typically called

the light bulb.