The Akosombo Dam (Volta Dam) is a hydroelectric dam on the Volta River in southeastern Ghana in the Akosombo gorge and part of the Volta River Authority. The construction of the dam flooded part of the Volta River Basin, and led to the subsequent creation of Lake Volta. The flooding that created the Lake Volta reservoir displaced many people and had a significant impact on the local environment. Lake Volta is the largest man-made lake in the world by surface area. It covers 8,502 square kilometres (3,283 sq mi), which is 3.6% of Ghana's land area. With a volume of 148 cubic kilometers, Lake Volta is the world's third largest man-made lake by volume, the largest being Lake Kariba which is located between Zimbabwe and Zambia in Southern Africa and contains 185 cubic kilometers of water.
The primary purpose of the Akosombo Dam was to provide electricity for the aluminium industry. The Akosombo Dam was called "the largest single investment in the economic development plans of Ghana." The dam is also significant for providing the majority of both Togo and Benin's electricity, although the construction of the Adjarala Dam hopes to reduce these countries' reliance on imported electricity.
The dam's original electrical output was 912 megawatts (1,223,000 hp), which was upgraded to 1,020 megawatts (1,370,000 hp) in a retrofit project that was completed in 2006.
The dam is 660 m (2,170 ft) long and 114 m (374 ft) high, comprising a high rock-fill embankment dam. It has a base width of 366 m (1,201 ft) and a structural volume of 7,900,000 m3 (10,300,000 cu yd). The reservoir created by the dam, Lake Volta, has a capacity of 148 km3 (120,000,000 acre⋅ft) and a surface area of 8,502 km2 (3,283 sq mi). The lake is 400 km (250 mi) long. Maximum lake level is 84.73 m (278.0 ft) and minimum is 73.15 m (240.0 ft). On the east side of the dam are two adjacent spillways that can discharge about 34,000 m3/s (1,200,000 cu ft/s) of water. Each spillway contains six 11.5-metre (38 ft)-wide and 13.7-metre (45 ft)-tall steel floodgates.
The dam's power plant contains six 170-megawatt (230,000 hp) Francis turbines. Each turbine is supplied with water via a 112–116-metre (367–381 ft) long and 7.2-metre (24 ft) diameter penstock with a maximum of 68.8 m (226 ft) of hydraulic head afforded.
The dam provides electricity to Ghana and its neighboring West African countries, including Togo and Benin. Initially 20% of Akosombo Dam's electric output (serving 70% of national demand) was provided to Ghanaians in the form of electricity, the remaining 80% was generated for the American-owned Volta Aluminum Company (VALCO). The Ghana Government was compelled, by contract, to pay for over 50% of the cost of Akosombo's construction, but the country was allowed only 20% of the power generated. Some commentators are concerned that this is an example of neocolonialism. In recent years the production from the VALCO plant has declined with the vast majority of additional capacity in Akosombo used to service growing domestic demand. More details
The dam's original electrical output was 912 megawatts (1,223,000 hp), which was upgraded to 1,020 megawatts (1,370,000 hp) in a retrofit project that was completed in 2006.
The dam is 660 m (2,170 ft) long and 114 m (374 ft) high, comprising a high rock-fill embankment dam. It has a base width of 366 m (1,201 ft) and a structural volume of 7,900,000 m3 (10,300,000 cu yd). The reservoir created by the dam, Lake Volta, has a capacity of 148 km3 (120,000,000 acre⋅ft) and a surface area of 8,502 km2 (3,283 sq mi). The lake is 400 km (250 mi) long. Maximum lake level is 84.73 m (278.0 ft) and minimum is 73.15 m (240.0 ft). On the east side of the dam are two adjacent spillways that can discharge about 34,000 m3/s (1,200,000 cu ft/s) of water. Each spillway contains six 11.5-metre (38 ft)-wide and 13.7-metre (45 ft)-tall steel floodgates.
The dam's power plant contains six 170-megawatt (230,000 hp) Francis turbines. Each turbine is supplied with water via a 112–116-metre (367–381 ft) long and 7.2-metre (24 ft) diameter penstock with a maximum of 68.8 m (226 ft) of hydraulic head afforded.
The dam provides electricity to Ghana and its neighboring West African countries, including Togo and Benin. Initially 20% of Akosombo Dam's electric output (serving 70% of national demand) was provided to Ghanaians in the form of electricity, the remaining 80% was generated for the American-owned Volta Aluminum Company (VALCO). The Ghana Government was compelled, by contract, to pay for over 50% of the cost of Akosombo's construction, but the country was allowed only 20% of the power generated. Some commentators are concerned that this is an example of neocolonialism. In recent years the production from the VALCO plant has declined with the vast majority of additional capacity in Akosombo used to service growing domestic demand. More details
