Projects Hydroelectric Beles Multipurpose Project

Beles Multipurpose Project

The Beles Multipurpose Project is located in the south-western bank of Lake Tana, some 350 km north-west of Addis Ababa and 70 km west of Bahar Dar, and is aimed to increase energy and power supply to the national grid.

The Project foresees the construction of a single stage power scheme with a total installed capacity of 468 MW, given by four Francis turbines to be installed in an underground powerhouse under a total gross head of about 335 m.  The average annual generation capability is 2050 GWh/y.  The hydropower plant can be excluded for irrigation purposes by the means of an underground by-pass.

Apart from a 820 m long approach channel, the project develops completely underground for a total length of about 20 km. A pressure headrace tunnel approx. 12 km long conveys water, up to 160 m3/s, from Lake Tana into the underground powerhouse, accomodating the four Francis turbine – generator units. The restitution into the Jehana River, a small tributary of the Beles River, is assured by a tailrace tunnel 7.3 km long, running free-flow.

The underground works consist of 1) a powerhouse cavern 105 m long x 19 m wide x 40 m high, 2) a transformers cavern 60 m long x 16 m wide x 13 m high, 3) two TBM excavated tunnels (headrace and tailrace respectively) characterized by an inner circular section of 7.2 m diameter, 4) an underground penstock approx. 340m long, 6m to 2.8m internal diameter, including steel lined pressure shaft 274m high, high pressure tunnel and manifold, 5) a surge shaft with a diameter of 18 m and a depth of 91 m, 6) a ventilation and cable shaft, 7) an access tunnel to the powerhouse, 1.2 km long and 8) an irrigation by-pass diverting up to 77 m3/s flow. The outdoor works are characterized by 400kV switchyard, concrete intake and outlet structures, river diversion works and regulating weirs along the Jehana River and more than 40 km access roads.

 

Coming soon - Presto on line