Post by pakedu on Aug 11, 2011 11:50:22 GMT 5
GHAZI BAROTHA HYDROPOWER PROJECT
The Ghazi-Barotha Canal
Official name غازى بروتھا
Locale Indus, Pakistan
Coordinates 33°46′48″N 72°15′35″ECoordinates: 33°46′48″N 72°15′35″E
Opening date 2002
Construction cost US$ 2.3 billion
Dam and spillways
Type of dam Run-of-the-river
Impounds Indus River
Power station
Type No
Turbines 5 × 290 MW
Installed capacity 1,450 MW
Introduction
The shortage of electrical power at affordable cost has long been identified as one of the main hurdles to the industrial and economic growth of Pakistan. The demand for electricity is growing rapidly and requires a considerable increase in the rate at which new generating capacity is introduced. Presently demand is met through a mix of thermal and hydroelectric plants. The percentage of thermal power generation has continued to increase in recent years, with a noticeable impact on unit cost of generation. WAPDA has continually sought to maximize the country’s capacity for Hydropower generation and reduce the dependence upon thermal power generation.
Ghazi Barotha Hydropower Project with a generation capacity of 1450 MW and an average energy output of 6600 GWh is a large, renewable and emission free source of energy towards WAPDA’s Vision 2025 goals.
The Project
Ghazi Barotha Hydropower Project is located on the Indus river downstream of Tarbela Dam. The Project utilizes the hydraulic head available between the tailrace at Tarbela Dam and the confluence of the Indus and Haro Rivers for power generation. In this reach Indus River drops by 76 m in a distance of 63 km. This Project possesses the minimum of environmental and social impacts.
Ghazi Barotha Hydropower Project consists of three main components. The Barrage, the Power Channel and the Power Complex. The Project utilizes the normal Tarbela Dam releases to provide year round maximum power generation during the daily hours of peak demand, including the months of May and June when reservoirs of Mangla and Tarbela Dams are historically at their lowest. This enhances the capacity of the whole power system by providing much needed relief in the form of cheap hydel energy.
The Barrage
The Barrage located 7 km downstream of Tarbela Dam, provides a pond which re-regulates the daily discharge from Tarbela by diverting the flow into the Power Channel. The principal features include 20 No. standard bays, 8 No. undersluices and 8 No. head regulator bays in addition to rim embankments, fuse plug and dividing island.
The Barrage can pass the design flood of 18,700 cumecs, equivalent to the flood of record, through the standard bays and undersluices at the normal pond level of El. 340 m. The fuse plug has been provided to pass the extreme flood upto the capacity of Tarbela’s spillway and tunnels equaling 46,200 cumecs.
The Power Channel
Ghazi Barotha Hydropower Project holds the record for the biggest concrete lined channel in the world. The channel is 51.90 km long with a concrete lining and design flow of upto 1600 cumecs at a water depth of 9 m. It has a bottom width of 58.4 m.
The Power Channel has a nearly contour alignment with hills on the left side and the land naturally draining towards the Indus River on the right side. The Power Channel intercepts fifty three nullahs (natural drains) of which twenty-seven major nullahs have been passed over the Power Channel by providing superpassages. The remaining twenty four minor nullahs are being discharged into the Power Channel through individual inlets whilst one nullah is passing underneath the channel through a culvert.
In addition to the thirty four road bridges, including bridges for both Islamabad-Peshawar Motorway and the G.T road, there are 12 pedestrian crossings over the Power Channel.
The main railway line joining Rawalpindi to Peshawar also crosses the power channel and required the construction of the second longest single span railway bridge in Pakistan. This may be the last riveted bridge of its type, constructed in Pakistan.
The Power Complex
The Power Complex having two headponds with a combined live storage capacity of approximately 25.5 million cubic meter is sufficient for the daily requirement of 4 hours peak generation. This means that in May and June when there is reduced generation from Tarbela and Mangla power houses, due to low reservoir levels, Ghazi Barotha Hydropower Project provides peak production of 1450 MW.
The five generating units in the Powerhouse are each fed by a 10.6 m diameter steel lined penstock. Each of the five 290 MW Turbo Generators can take a peak flow of 460 cumecs.
Power Complex has been provided with a self priming siphon spillway of 1600 cumecs capacity, having energy dissipation in a stilling basin and a baffle chute.
The power transmission is through 500 KV double circuit lines to WAPDA’s national grid system.
Mechanical and Electrical Equipment
The installed power generating capacity is 1450 MW consisting of five units each of 290 MW. The units have a design flow of 400 cumecs at optimum gate opening and 460 cumecs at full gate opening for a design head of 69 m.
The principal items of power equipment are as follows:
Five Francis turbines each with a 290 MW generator which together have a combined power generating efficiency of 94%.
Five three-phase banks of transformers, each single-phase unit being 107.5 MVA.
500 KV conventional outdoor switchgear configured in one-and-a-half breaker arrangement.
12 cranes with lifting capacities from 6 to 450 tons.
With a project which is spread over such large area, it was considered necessary both for safety and efficiency that it should be monitored and controlled centrally. This has been achieved by providing two independent distributed control systems (DCS) one each at the Barrage and Power Complex which share information through an optic fiber cable link.
Environmental, Resettlement and Social Aspects
The guiding principle for Ghazi Barotha Hydropower Project has been to maintain close contact between the engineering and environmental planners, social scientists, the local community groups and NGOs, right from the feasibility stage to Project construction.
This process allowed the planning teams to identify and avoid or mitigate, all potentially serious, adverse environmental, social and archaeological effects. The locations for Barrage and Power Complex as well as the alignment of the Power Channel have been selected in such a way that it avoids where possible, the disruption of villages, cultural properties and other infrastructures. However, only 110 dwellings were affected, and for them three resettlement villages have been established in the vicinity of the Project area where all the basic amenities like water supply, sewerage, schools, mosques etc. have been provided by WAPDA to the affected households resulting no out of area resettlements.
A Project NGO, namely Ghazi Barotha Taraqiati Idara (GBTI), was established and funded by WAPDA to assist in mitigating the genuine public concerns on the matters relating to land valuation and compensation, displacement of affectees and resettlement, loss of livelihood, employment and other social and environmental concerns. In addition to this, GBTI has implemented an integrated regional development plan and carried out development activities in the project affected areas.
The power channel alignment is mostly in cut, having a total of 76 million cubic meter of excess spoil material extracted out of the channel excavation. To avoid hauling the material over long distances, the spoil material has been used for construction of spoil banks along the power channel, terracing of waste land, reclamation of land along the left bank of Indus river and filling of deep gullies, whilst providing an environmentally satisfactory permanent solution. The spoil banks and gullies have been leveled, covered with topsoil and to be provided with tubewell irrigation. It has been planned to sell back these developed banks to the interested affectees for the cultivation purposes. Presently about 856 Kanals and 16 Marlas of land out of total land in Khyber Pakhtunkhwa (KPK) province has been sold back to 50 No. PAPs original land owners after proper leveling. In Punjab province the action on resale of land could not be started yet as necesary NOC from provincial govenment is still awaited. In KPK Province, on the demand of land owners 18 tubewells are planned to be installed on spoil banks and Hydrogeology department of WAPDA has been contracted for deposit work. In financial year 2011-12, 6 No. tubewells will be installed on spoil banks sold to land owners in KPK Province.
Against this disruption to the local community the construction works employed more than 10,000 project affected persons and many local companies. Over the course of the construction, this influx of capital into the local economy has had a significant effect on improving the business opportunities and economic growth particularly in the Project area.
To avoid the environmental concerns of the people residing along the banks of Indus River downstream of Ghazi Barrage, compensation water is being released through barrage into the original course of the river. For the villages on the both sides of power channel, 46 No. of crossings have been provided over the power channel.
Project Implementation
In the Feasibility Report, the time for Project implementation of Civil and M&E contracts was estimated as 63 months starting from 01 April 1993. With the approval of PC-1 of Preparatory Works including land acquisition, relocation, resettlement, construction of colonies and other infrastructure for the Project were commenced in 1995. The implementation of the Project ultimately came to fruition with the inauguration ceremony of the Commissioning of Unit No. 1 and Unit No. 2 on 19 August 2003 by the President of Pakistan. The work on the commissioning of other units continued and Unit No. 5 was commissioned in April 2004. The construction of the North Headpond was completed in December 2004, thus completing the implementation of the Project works.
Project Financing
The PC-I of the Project was approved by Government of Pakistan in July 1994 at a total cost of Rs. 89840 million. The total cost which has been incurred on the Project is Rs. 96957 million.
The Project has been funded by WAPDA supported by the following international lending agencies:
World Bank
Asian Development Bank
Japanese Bank for International Cooperation
Kreditanstalt fuer Wiederaufbau (KfW)
European Investment Bank
Islamic Development Bank
This Project is an important component of Pakistan’s power system. The least cost status of the Project remains valid for the full range of sensitivity analysis performed. The Project has highly favourable economic parameters, it has an EIRR of 22.19% and FIRR of 13.76%. The economic and financial returns have shown that the Project forms a part of the least cost generation expansion plan for Pakistan.
PRINCIPAL DATA
BARRAGE POWER COMPLEX
Normal Pond level 340.0 m
Design Flood 18,700 cumecs
Survival flood 46,200 cumecs
Embankments Headponds and Forebay
Fuseplug, Rim and Dividing Island Normal pond level 334m
Standard Bays Live volume 25.5 Mm3
No. of openings 20 Siphon spillway
Crest level 332.2m Discharge capacity 1600 cumecs
Head Regulator Crest level 334.5m
No. of opening 8 Intake
Crest level 333.0m No. of opening 10
Undersluices Crest level 305.5
No. of opening 8 South Sill
Crest level 326.0m No. of openings 3
Sill level 323 m
POWER CHANNEL
North Sill
No. of openings 10
Design flow 1,600 cumecs Sill level 321 m
Longitudinal slope 1:9600
Length 51,906 m HYDRO MECHANICAL EQUIPMENT
Full supply depth 9 m
Bed width 58.4 m Penstocks
Side slope IV: 2H No. 5
Lining thickness 135 mm Diameter 10.6 m
Structures Length 222 m
Turbine
Road bridges 34 Type Francis
Railway bridge 1 Number 5
Pedestrian Crossings 12 Full Gate output 295 MW
Superpassages 27 Generator/Transformers
Drainage Inlets 24 Number 5
Escapes 5 Continuous Rated output 3x107.5 MVA
Culverts 1 Rated Voltage HV:LV 515 \/ 3:18 KV
Switchyard
No. of 500 KV Bays 6
Scheme of Layout Breaker & Half Scheme
MISCELLANEOUS INFORMATION
EXECUTING AGENCY Contract ME-02, Generators and auxiliaries
Water and Power Development Authority
WAPDA House, Lahore, Pakistan Mitsui/Toshiba, Japan
ENGINEER Contract ME-03 Transformers and Miscellaneous Equipment
Pakistan Hydro Consultants Dangfang Electric Corporation, China
A Joint Venture of
National Engineering Services Pakistan (Pvt)
Ltd, Pakistan Contract ME-04 Cranes
Consulting Engineers (Pvt)
Ltd, Pakistan
TECHNICAL DATA OF BAROTHA POWER COMPLEX FOR THE YEAR 2010-11
1. Gross Generation During the year 7434.793 MKWH
2. Net Electrical Output During the year 7354.112 MKWH
3. Maximum Generation (Month-wise) during the year
740.09 MKWH
4. Maximum Daily Generation during the year
26.575 MKWH
Dated 25.10.2010
5. Maximum Load D
1450 MW
Dated 30.06.2011
6. Unit wise Generation During the Month of June U#1
1463.663 U#2
131.954 U#3
123.586 U#4
146.980 U#5
152.030 MKWH
Total 701.213 MKWH
