Beles Hydroelectric Power Plant
Encyclopedia
The Beles Hydroelectric Power Plant, sometimes referred to as Beles II or Tana Beles, is a run-of-the-river hydroelectric power plant in Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...

 near Lake Tana
Lake Tana
Lake Tana is the source of the Blue Nile and is the largest lake in Ethiopia...

. The power plant receives water from the lake and after utilizing it to produce electricity, the water is then discharged into the Beles River
Beles River
Beles River is a river of western Ethiopia. A tributary of the Abay river , the Beles rises in Dangur woreda to flow in a south-west direction to its confluence. Its catchment area amounts to about 14,200 square kilometers....

. The plant will have an installed capacity of 460 MW and when fully operational and will be the largest power plant in the country. It is also expected to help provide water for the irrigation of 140000 ha (345,947.2 acre). It was inaugurated in May 2010 and its construction was negatively perceived by downstream Egypt.

Background and construction

In 1992, the first feasibility study was complete for the project, a 200 MW power station. A later study and final design was completed in 2005 for the current 460 MW plant. The Government of Ethiopia signed a contract with SELI to build the plant on July 8, 2005 and construction began soon after. Because of the project's remote location, transportation and manning of personnel and equipment was difficult, often taking 4-5 months for supplies to arrive. On June 2, 2007, a tunnel boring machine
Tunnel boring machine
A tunnel boring machine also known as a "mole", is a machine used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They can bore through anything from hard rock to sand. Tunnel diameters can range from a metre to almost 16 metres to date...

 (TBM), operated by SELI, began boring the 7.2 km (4.5 mi) tailrace tunnel and completed it on May 31, 2008. Tunneling was carried out seven days a week in three eight-hour shifts a day. The TBM averaged 20 m (65.6 ft) per day while in January 2008, a maximum daily amount of 36 m (118.1 ft) was achieved. The TBM for the 12 km (7.5 mi) headrace tunnel broke through, completing it on August 11, 2009. Salini Costruttori awarded a sub contract to construct the actual power station to VA Tech Hydro. On May 11, 2010, the first 115 MW generator at the power plant began operation and on May 14, 2010, the plant was inaugurated. The project's cost was around $500 million USD. The rest of the generators were expected to be online within six weeks.

Design

The Beles Hydroelectric Power Plant receives water from Lake Tana where it is transferred to a power station and then discharged through another tunnel and into the Beles River. This is first accomplished by an inlet on Lake Tana, where the power station can utilize 9120000000 cubic metre of the lake's volume for power production. The inlet channel is 43 m (141.1 ft) wide, 11.5 m (37.7 ft) high and its flow into the headrace tunnel is controlled by five floodgate
Floodgate
Floodgates are adjustable gates used to control water flow in flood barriers, reservoir, river, stream, or levee systems. They may be designed to set spillway crest heights in dams, to adjust flow rates in sluices and canals, or they may be designed to stop water flow entirely as part of a levee or...

s. The headrace tunnel transfers the water to the southwest along its 12 km (7.5 mi) length within its diameter of 8.1 m (26.6 ft). At the end of the headrace tunnel, it converts into a 6.5 m (21.3 ft) diameter and 270 m (885.8 ft) long penstock
Penstock
A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydraulic turbines and sewerage systems. It is a term that has been inherited from the technology of wooden watermills....

 before reaching the power station. At the power station, water is delivered to four Francis turbine
Francis turbine
The Francis turbine is a type of water turbine that was developed by James B. Francis in Lowell, Massachusetts. It is an inward-flow reaction turbine that combines radial and axial flow concepts....

s powering four 115 MW generators. The power station is an underground cavern type and is 82 m (269 ft) long, 17.6 m (57.7 ft) high and 38.5 m (126.3 ft) wide. It has a 91.2 m (299.2 ft) deep and 8 m (26.2 ft) diameter surge shaft as well. Once the water is used in hydroelectric production it is then discharged from the power station to the Beles River via a 7.2 km (4.5 mi) tailrace tunnel with the same diameter as the headrace. Normal water level at the inlet is 1800 m (5,905.5 ft) above sea level and the power station resides at 1450 m (4,757.2 ft), allowing for 350 m (1,148.3 ft) of hydraulic head
Hydraulic head
Hydraulic head or piezometric head is a specific measurement of water pressure above a geodetic datum. It is usually measured as a water surface elevation, expressed in units of length, at the entrance of a piezometer...

. The project is also expected to help irrigate 140000 ha (345,947.2 acre) in the future as well.

Egyptian opposition

The Beles Hydroelectric Power Plant is part of a larger issue amongst the Nile River Basin countries as the Beles River is a tributary of the Blue Nile
Blue Nile
The Blue Nile is a river originating at Lake Tana in Ethiopia. With the White Nile, the river is one of the two major tributaries of the Nile...

 and Lake Tana supplies the basin as well. After the inauguration of the power plant, statements were released from a meeting of Egyptian officials, one of which was "Tana Beles dam aims to provoke Egypt’s anger and lead it to take swift diplomatic action which would turn the global opinion in favor of the upstream Nile countries." The officials, many involved in the Nile River Sector, stated they had no information about the project. The power plant was inaugurated at the same time as a Cooperative Framework Agreement over the Nile Basin was signed by upstream countries such as Uganda
Uganda
Uganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...

, Rwanda
Rwanda
Rwanda or , officially the Republic of Rwanda , is a country in central and eastern Africa with a population of approximately 11.4 million . Rwanda is located a few degrees south of the Equator, and is bordered by Uganda, Tanzania, Burundi and the Democratic Republic of the Congo...

, Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...

, and Ethiopia, but downstream countries Sudan and Egypt refused to sign. Under colonial-era accords, Sudan and Egypt receive 90% of the Nile's flow and can reject any upstream projects that would impede it.
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