THE Birecik hydro power plant in southern Turkey is the largest build, operate and transfer (BOT) hydro power plant in the world, according to its developers, and is Turkey’s biggest privately-funded hydro power project. The 672MW plant was constructed in just four years and eight months by Birecik AS. This private company also provided funding for the project and will operate the plant for the next 15 years before it is handed over to the Turkish government under the BOT agreement.
Development
Birecik is part of a government plan to promote and develop the region of southeast Anatolia. The plan involves the construction of a number of dams on the Tigris and Euphrates rivers for irrigation and power generation. Several projects have already been completed.
Approximately 43% of Birecik AS is held by Philipp Holzmann of Germany (the lead investor in the project), strabag of Austria and Gama of Turkey. TEAS (Turkish electric utility company) holds 30% of the company, while the remaining shares are distributed among the hydroelectric and mechanical suppliers, planners and operators.
The civil works were executed by a joint venture between GAMA, Strabag and Philipp Holzmann. Philipp Holzmann led the consortium and represented the European countries which participated in the project.
The dam project cost US$1.09B (2.3B DM) to construct and this capital was mainly provided by international investors. The investment will be repaid through the sale of electricity during the 15-year operation period.
The plant is expected to generate 2.5B kWh per annum and three of the 6 x 112MW Francis turbines have already started operating, 11 weeks ahead of schedule. The remaining turbines will be connected consecutively to the grid over the next few months and are expected to be in commercial operation by 30 June 2001, more than 12 weeks ahead of schedule. Birecik will start commercial operation within the 66-month schedule.
Birecik dam is located downstream of the Ataturk dam and contributes to the overall exploitation of the Euphrates for energy purposes. The dam is 2.5km long and 62.5m high, with embankments on the left and right sides and a 489m wide concrete gravity dam in the centre which incorporates the power house, intake works and spillway. The retaining volume of the dam is over 620M m3 and the watershed of the reservoir covers an area of over 100,000km2.
About 80% of the dam’s length consists of an earthfill embankment dam with an impervious core made of clay-like loamy sands. The fill comes from alluvial deposits on the left bank about 3.5km from the structure. Suitable material for the impervious fill comes from the right bank about 1.7km away.
The power house contains 6 x 112MW Francis turbines. Water is directed through penstocks, each with a diameter of 8.4m and a gross head of 44.65m. A flow of 320m3/sec is possible for each turbine.
The spillway can divert a floodwater quantity of more than 17,000m3/sec and discharge is controlled by radial gates. Four bottom outlets are integrated into the spillway structure.
Additional work at the plant included:
• A grout curtain under the dam structure to improve the impermeability of the adjacent limestone.
• A transformer station as an outdoor switchyard.
• Dredging operations in the river bed between the dam and the city of Birecik in order to ensure the desired discharge and as flood protection for the city.
• A temporary heavy duty traffic bridge across the Euphrates during construction.
• 106 residential units for construction and operations staff.
• Access from the facility to public roads.
Role model
Statistics from the World Bank and other institutions reveal that delays in construction and cost overruns can be frequent occurrences for hydro power plants. Philipp Holzmann believes that the Birecik project, which was completed on schedule and under budget, could serve as a role model for the efficiency of private companies in the planning, financing, construction and operation of such plants in the future.