baduludena village hydro project report
TRANSCRIPT
Feasibility report /
Project Report
“Baduludena” village hydro project
Prepared By
Practical Action (Intermediate Technology Development Group – South Asia)
Contact Person
Gihan Sajeew M.A.
Project Manager –Energy
T.P: 0112829412/0772296240
Fax: 0112856188
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Table of Contents
1. INTRODUCTION ................................................................................................................... 3
1.1. Location of the site. .......................................................................................................... 3
1.2. Contact person .................................................................................................................. 3
1.3. Developer ......................................................................................................................... 4
2. SITE DETAILS ....................................................................................................................... 4
2.1. Proposed power output ..................................................................................................... 5
2.2. Type of ownership ............................................................................................................ 5
2.3. Leadership prospects ........................................................................................................ 5
3. MARKET FOR POWER......................................................................................................... 6
3.1. Types of load .................................................................................................................... 6
3.2. Prospectus for rival power sources................................................................................... 7
4. WATER RIGHTS.................................................................................................................... 7
4.1. Land Rights ...................................................................................................................... 7
4.2. Prospects for future difficulties ........................................................................................ 7
5. GEOTECHNICAL CHARACTERISTICS OF THE SITE ..................................................... 8
6. HYDROLOGICAL CHARACTERISTICS OF THE SITE .................................................... 9
6.1. Estimate of the Run-off .................................................................................................. 10
6.2. Flow Duration Curves of the catchment ........................................................................ 12
6.3. TURBINE DESIGN FLOW .......................................................................................... 14
7. HEAD MEASUREMENTS .................................................................................................. 14
8. CONSTRUCTION AND EQUIPMENT PROPOSALS AND COSTS ................................ 15
8.1. PAYMENT SCHEDULE ............................................................................................... 16
9. WORK PLAN........................................................................................................................ 16
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1. INTRODUCTION
Baduludena is a small village with a population of 120 people living in 25 houses situated
in Haldummulla Divisional Secretariat in Badulla district in the Uva province. The
village is accessible from Marangahawela on the A4 main road at 168km post and then
along Marangahawela –UvaKosgama by road. At present the village has no vehicular
access and is accessible only by a 2.5 km long footpath from UvaKosgama Village. The
Uva-Kosgama is about 8km off from Marangahawela. The nearest town is Haldummulla
situated 15kms from the village.
The main occupation of the villagers is agriculture. The national electricity grid is about
4km away from the village and it is very unlikely that the grid would be extended for the
next 20 years. The main energy sources in the village are firewood for cooking, Kerosene
for lighting and car batteries to watch Black and White TV. Each household has to spend
at least Rs. 750 per month to meet the energy needs. The village has no post office,
medical facilities or any other government institution except the primary school.
The main need in the hour is a road for the village but providing electricity too can
contribute to improve the social and living condition to a greater extent.
DewagalleAra, a tributary of Walawe River, runs about 2kms away from the village and
this stream can be exploited for the production of electricity to the village.
1.1. Location of the site.
The site is located about 2kms south west of Baduludena Village, on the bank of
Dewagalle Ara, which is a small tributary of Walawe Ganga. The power house site shall
be located close to the confluence of Walawe Ganga with DewagalleAra.
Fig 1 shows the access route to the village and the location of the proposed site.
The provincial boundary of Uva and Sabaragamuwa falls along the DewagalleAra in this
area. Accordingly Imbulpe Division in Ratnapura district and the Haldummulla Division
in Badulla district will be on right and left side of the stream.
1.2. Contact person The villagers have formed an electricity consumer society and Mrs.Dinusha Kumari of
Baduludena has been elected as the secretary of the society. She will be the contact
person for the proposed power project.
Name: Dinusha Kumari
Address: Baduluden, Uva Kosgama, Haldummulla
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1.3. Developer
The developer of this Project is Practical Action (formerly ITDG); through several years
of hard work in micro hydro sector with the rural communities in Sri Lanka, has
identified and proved a novel and sustainable strategy in empowering the disadvantaged
communities. The strategy is the 'Electricity Consumers Society' (ECS) of which the
objective is to enable communities to have their own renewable energy source of which
they have control in all aspects. The most significant factor of the strategy is that it (ECS)
has, while finding an effective and alternative energy-source viz. village hydro, made the
energy supply a community-responsibility, thereby making the community independent
The experience earned with this strategy was shared with the governmental officers, the
NGOs, banks, multilateral agencies and the individuals interested, through seminars and
observation visits to village hydro sites. The result was the national and international
recognition of Practical Action-South Asia's work and the strategy in village hydro sector
by many, after further research on the work. For example, the Government of Sri Lanka
has recognized the services of ECS. The World Bank, on the other hand and for the first
time, accepted the approach by including village hydro in its RERED (Renewable energy
for rural economic development) project
This is in addition to the ITDG-South Asia's own achievements such as, developing and
sustaining the village hydro technology and inclusion of village hydro into the National
Energy Policy.
Contact Person
Name: Eng.M.A.GihanSajeew
Address: Practical Action, No 5, Lionel Edirisinghe Mw, Colombo 5
Telephone: 0772296240, 0112829412
2. SITE DETAILS
DewagalleAra is a small tributary of Walawe Ganga, with a catchment area of 4.6 sq.
kms. The annual average rainfall is about 1900 mm in the project site. The catchment is
in the transition zone from wet zone to semi dry zone. The Samanalawewa Reservoir is
located about 3kms to the west of the stream at a higher elevation. It has been observed
that several springs also appeared in the upper reaches of stream with the impounding of
Samanalawewa reservoir in 1992 contributing to the base flow throughout the year. It is
estimated that about 60 l/s could be diverted for the operation of the proposed micro
hydro power plant
A diversion weir shall be located in the lower reach of the stream (Pusveltenna) to divert
the stream flow to the power canal on left bank. The design water level would be 385m
msl. A side spill shall be introduced to regulate the canal flow. The length of the canal
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will be 70m and the forebay tank with a settlement basin shall be included as shown in
the layout map (Fig 2).
From the forebay water shall be conveyed to the power house using PVC penstock (225m
in diameter). The length of the penstock shall be 350m. The penstock shall be taken to the
left bank of the river. The power house shall be located on the left bank of the stream and
the power house elevation shall be 323m MSL to ensure the net head of 55m.
The present water level of the Walawe Ganga is around 319m at the confluence with
Dewagalleara. This will ensure the powerhouse will be well above flood levels of
Walawe Ganga.
2.1. Proposed power output
The design water level at the intake 385m MSL
The design water level at the forebay 383m MSL
The turbine level 323m MSL
Gross Head 60m
Head loss in the penstock 4.2m
The net head 55.8m
Design flow 60 liters per second
Efficiency of the turbine & generators 60%
Power Output 21.19kW
2.2. Type of ownership The power plant shall be developed by Practical Action and owned by the Baduludena
United Electricity Consumer’s Society of Baduludena, UvaKosgama, Haldummulla. The
Operation and maintenance is done by the ECS of Baduludena. The Project has been
registered with Sri Lanka Sustainable Energy Authority.
2.3. Leadership prospects
Most of the young generation of the village can read and write well. Some of them have
completed vocational training courses in training centers. Some of them are skilled
laborers like carpenters or masons. With a short training on the job, they can take on the
appropriate responsibilities to handle the maintenance and operation of the power plant
on a sustainable manner.
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3. MARKET FOR POWER
Under the Gamidiriya Programme, a new road to the village is under construction. When
the vehicular access would be available to the village, the living conditions of villagers
drastically improve and villagers will tend to buy various household electric appliances
such as refrigerators, color TVs, water pumps etc. Average consumption of 500W per
house could be expected.
A rice mill and a grocery are also required for day to day requirements of the village.
The primary school in the village will have computer facilities in near future and use of
other electric appliances such as bulbs, fans, heaters could be expected.
There is a proposal to build a grid connected mini hydro power plant using the river flow
in Walawe Ganga and the power shall be connected to the national grid from
Mulgama/Watawala. However the access road for the power plant shall be constructed
through Baduludena village and the construction camp also will be erected in
Baduludena. When this project is commenced, accommodation for a large no of workers
will have to be provided in Baduludena village during its construction period.
Subsequently, operation & maintenance staff of the power plant would permanently stay
in the village; the village society can meet their electricity requirements by giving them
surplus power for these parties in the future and increase the no of members.
3.1. Types of load In the Day time: It is expected to provide electricity for the school to use computer
facilities in future. Other than that domestic load would be the main load types during the
day.
In addition, excess power could be utilized for pumping water from nearby stream
(BaduludenaAra) for agricultural usage.
Usage Load Type Power (W)
School 2 computers 300
2 electric fans 150
5 bulbs 125
Domestic 150 electric bulbs 4000
5 electric irons 5000
15 color TV 2000
5 B&W TV 250
15 radios 750
40 mobile phone chargers 80
10 food processors 700
10 Ceiling Fans 750
Agriculture 5 Pumps 20kW
1 rice mill 15kW
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3.2. Prospectus for rival power sources
The national grid is about 4kms away from the village and there is no any other village
in between as the lands belongs to forest. Therefore it is very unlikely to extend the
national grid to this village. Besides, the national grid electricity tariff is much higher
than the village scheme. Therefore, the national grid would not be a threat to the
proposed project.
The solar power has been using in few houses for more than 3-5 yrs. It is very expensive
and cannot be used for high power consuming appliances. Besides charging batteries is
very cumbersome as closest battery charges to the village could be found at Haldummulla
, 15kms from the village
Accordingly, prospects for rival power sources are non existent.
4. WATER RIGHTS
Water rights shall be obtained from Divisional Secretary- Haldummulla.
4.1. Land Rights Land rights shall be obtained from Divisional Forest Office, Badulla for the construction
of weir, canal and penstock & Power House in Baduludena proposed forest reserve.
4.2. Prospects for future difficulties Vehicular access will not be available up to the power house even in the future.
Therefore major repairs such as replacement machines etc. cannot be done immediately.
Power interruptions longer lasting few days to weeks could be expected. Accessibility
can be obtained if the proposed grid connected hydro power project is being constructed.
Seasonal forest fires are very common in the area during dry weather .Therefore special
precautions have to be taken to protect PVC penstock line and the transmission line in
certain sections. So the penstock will be buried one or two feet and the transmission line
will construct with concrete poles.
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5. GEOTECHNICAL CHARACTERISTICS OF THE SITE
The project area falls within the major lithological complex known as highland series,
which is made up of high grade metamorphic rocks. Out of the rock types forming the
highland series, mainly following rock types are present in the project area.
1. Quartz rich biotite gneiss
2. Biotite gneiss
3. Charnokitebiotite gneiss
4. Charnokite
5. Garnetiferousgranulites
White crystalline limestone which occurs as narrow bands within the highland series
was noted in exposures along the stream.
Dewagulu Ara flows through a fairly steep valley. In upper reaches, old scar of an earth
slip could be identified and 5-7m deep overburden could be observed in this section. In
lower reaches of the stream, slopes do not show any landslide activity.
Upstream section of the proposed weir site along the stream shows mild to moderate
gradient. Exposed bed rock could be seen in several places below the boulders along the
stream. The slopes are covered with grayish brown residual soils of estimated thickness
of 2-3m. From weir site to the downstream, stream drops fast forming small waterfalls
and rapids over the exposed bed rock.
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6. HYDROLOGICAL CHARACTERISTICS OF THE SITE
The site is located in the transition zone from wet zone to semi dry zone. The annual
rainfall of the area is about 2000ml. Rainfall data is available for more than 6 yrs at a
weather station in Samanalawewa project. The location is Kumbalgama, just 2 kms away
from the catchment of the stream. The daily rainfall values from 1999 to 2007 (except the
year 2005) are available. The annual rainfall in the area was between 1700 ml and 2500
mm. Dewagalle Ara has a catchment area of 4.6 sq. kms.
Estimate of runoff
Two main sources contribute to the stream flow at the location of the intake weir. They
are:
1. Ground water discharge from springs along the Killekanduraara fed by
Samanalawewa reservoir
2. Surface runoff of the catchment.
Ground water
The Samanalawewa Reservoir is located about 3kms to the west of the stream at an
higher elevation. It has been observed that several springs appeared in the upper reaches
of the stream with the impounding of Samanalawewa reservoir in 1992. A large spring
can be found in KilleKandureAra which is a branch of the DegalleAra. In general the
discharge from these springs increases with the increase of reservoir level. A weir has
been installed inKilleKandureAra stream for continuous monitoring of discharge by
Ceylon Electricity Board (CEB). A few readings of the flow measurement in
KilleKandureAra given in Appendix 3. It can be seen that minimum flow there exceeds
25 liters/sec.
Surface runoff
The catchment of the DewaguluAra is shown in Fig 3. The extent of the catchment is 4.6
sqkms. Surface runoff in the catchment drains into the DewaguluAra through dry and wet
streams on fairly steep valleys in both banks.
Kumbalgama rain gauging station is located within the catchment and but the observation
period is limited to 8 years. The possibility of use of rainfall data of Balangoda rain
gauging station which is the second nearest and having long historical data was also
considered. However those records were found to be not representative data for the
catchment and it will over estimate the actual flow.
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Fig 4: Average monthly Rainfall Distribution at Kumbalgama
The average annual rainfall is about 1912mms and the monthly rainfall distribution is
shown in Fig 2. From the above diagram it can be seen that both monsoon equally
contribute to the stream flow and the lowest rainfall experienced during the months of
June to August. Accordingly separate analysis of Yala and Maha seasons and water years
were not considered for this study.
6.1. Estimate of the Run-off
The total catchment of the proposed project is about 4.6 sqkms. Catchment area
measurements were carried out using 1:10,000 contour maps with a high accuracy. In
order to estimate the runoff coefficient of the catchment very conservatively, following
assumptions were made in conformation with the guidelines given in Design of Irrigation
Headworks for small catchments (A.J.P. Ponrajah)
The pan evaporation data is available for Ratnapura and it was found more appropriate
for the study. (Table 6). In the absence of direct stream flow measurements, a long term
stream flow series at the proposed site has to be generated from a mathematical model.
For this purpose rainfall runoff model shall be used with assumed model parameters and
selection of these parameters shall be carried out from the experience in similar
catchments in the country. The NAM conceptual model developed by the Danish
Hydraulic Institute in Denmark (DHI) shall be used in this study with observed rainfall
and evaporation Data as inputs.
Following parameters were assumed for the NAM Model.
Upper Zone Moisture Umax =5
Average Monthly Rainfall Distribution at Kumbalgama
Rain
fall
(mm
)
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Lower Zone Moisture Lmax= 100
Overland Runoff Coefficient CQ of = 0.50
Time Constants for overland flow routing CK1 =10.0
-do- CK2 =20.0
Base flow parameters for routing (upper zone) CKbfu = 400
Base flow parameters for routing (lower zone) CKbfl = 8000
Correction for the catchment Carea = 0.95
Pan Coefficient Ceva =0.80
The runoff rainfall ratio found from the generated flow rates from the model was 56%.
The Generated Runoff Volume at weir site of the DewaguluAra is given in Table 7.
Base flow of the catchment was taken as 25 litres/S.
Mean annual Runoff = 5.704 MCM
Standard Deviation = 0.347 MCM
P(X) 75% = 5.345 MCM
From the generated flow data of average climatic conditions (50% Probability), the
variation of runoff during the year were computed on monthly basis. 75% probable
climatic conditions were identified and the generated monthly runoff volumes for (P(x)
=75%) are given in Table 8.
Table 9 shows the 75% probable average flow rates of DewaguluAra (1999- 2007).
The 50% probable average daily flow rates and the 75% probable daily flow rates of the
catchment were established with average daily rainfall figures of Kumbalgama Station.
The results are shown in Table 10 & Table 11 respectively. Fig 4 shows the average flow
regime for 75% probability.
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6.2. Flow Duration Curves of the catchment
The flow duration curves (FDC) represent the variation of runoff in a year with respect to
their magnitude and not according to their calendar sequence. FDC provides vital
information in selecting hydro mechanical components of the power plant. For the
catchment FDCS were derived for P(X) = 50% and P(X) = 75% using Table 6 and Table
5 respectively. These curves are shown graphically in Fig 6 & Fig 7 below.
Riv
er
Flo
w (
cum
ecs
)
Fig 5 Average Flow Regimefor P(X)=75% (cumecs) Dewagulu Ara-Weir
site A=4.6 sq.km
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Riv
er
Flo
w (
cum
ecs
)
Percentage Exedence (%)
Fig. 6 Flow Duration Curve for P(X)=50%-Dewagulu
Ara,Weir site A=4.6 sq. km
Riv
er
Flo
w (
cum
ecs
)
Percentage Exedence (%)
Fig 7 Flow Duration curve for P(X)=75% (cumecs) Dewagulu Ara-
Weir site A=4.6 sq.km
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From these curves, upper and lower deciles, quadrilles’ and the median could be
obtained. Following are the ordinates of the two flow duration curves.
TABLE 1 FLOW-DURATION DATA
(for the catchment)
% Exceedance
Discharge (m3/sec)
P(x)=50% P(x)=75%
10 1.700 1.600
20 1.100 1.050
25 0.900 0.800
30 0.750 0.680
40 0.530 0.460
50 0.350 0.330
60 0.230 0.220
70 0.150 0.120
75 0.120 0.090
80 0.060 0.056
90 0.010 0.010
6.3. TURBINE DESIGN FLOW
Although the stream flow exceeds 100 lts/sec more than half of the year, the design flow
was chosen as 60 l/s as the load required is about 20 kW. It can be seen from the figure 7,
the design flow is available 78% of the time with P(x) =75%
7. HEAD MEASUREMENTS Head measurement was done by using an engineering level and the level sheet is given in
appendix 1
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8. CONSTRUCTION AND EQUIPMENT PROPOSALS AND COSTS
No Cost element Specifications Rate Total (LKR)
1 Weir width is 5m and 0.6m
height concreted weir 35,000.00
2 Head race canal 60m long concrete lined 65,000.00
3 Fore-bay tank concreted 35,000.00
4 Settling tank concreted 35,000.00
5 Thrash rack steel 15,000.00
6 Spill way Masonry walled 22,000.00
7 UPVC penstock 225mm T600,360m
length 1,000,000.00
8 Penstock anchoring Steep locations anchoring
needed 20,000.00
9 Turbine manifold
,valves Galvanized steel 275,000.00
10
Turbine, turbine and
generator mountings,
turbine housings,
shaft and bearings.
3 jet turbine ,Cast iron
runner, bearings, Casing
,gates
685,000.00
11 Power House 75,000.00
12 Control Unit
3 phase electronic load
controller, ballast heaters,
protection ,all power
cables, power house
wiring
625,000.00
13
Brush less
Synchronous
Generator
3 phase ,30kW 235,000.00
14 Transmission line 1.8km 1,000,000.00
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Administration cost,
Physical
contingencies & Price
escalation
250,000.00
Grand Total 4,372,000.00
Closure 1:
The budget (LKR 4,372,000.00) doesn’t include any taxation and statutory deductions to the
authorities, if so it is also should add to the final budget.
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8.1. PAYMENT SCHEDULE
Payment Percentage (%) from the
total budget
1. Advance payment to start works 30
2. Second Payment – after complete the turbine ,controller
and site delivery
40
3. Final Payment – Within one month after commissioning
the project
30
9. WORK PLAN
No Work item 1st
month
2nd
month
3rd
month
4th
month
5th
month
6th
month
1 Formation of electrical
consumer society and strengthen
ECS
2 Purchase of penstock pipes and
accessories
3 Construction of Weir and fore
bay tank
4 Construction of Power House
5 Laying of penstock Pipes
6 Supplying of electrical posts
7 Construction of electricity
distribution networks
8 Fabrication of mechanical
equipment
9 Fabrication of electrical and
electronic equipment
10 Installation of electro mechanical
equipment
11 Test running and fine tuning
12 Connecting to the load centers
13 Handing over the project to
Electrical consumer society