The first power generation test for Beles Multipurpose Project, the hydroelectric power project under the integrated team of Ethiopian Electric Power Corporation (EEPCo) and Salini Construction SPA will take place by late January 2010.
The 7.1 billion Br project, financed by the EEPCo and loans from development partners, was started on June 8, 2006. It will have a capacity of 460mw. Currently, the tunnel breakthrough and installation of electromechanical parts has been completed.
Presently the project workers have started clearing out the tunnel rail lines, water pipes, electric wires and air-conditioning lines used during construction, according to Kifle Horo, project manager of the integrated team of EEPCo and Salini.
The completion of the tunnel, which runs 12km from the water inlet on Lake Tana to where it gushes out driving the turbines, was inaugurated on November 9, 2009. Tefera Walwa, minister of Capacity Building; Alemayehu Tegenu, minister of Mines and Energy; Ayalew Gobeze, president of the Amhara National Regional State and Miheret Debebe, CEO of EEPCo were all present. The project is located 130kms from Bahir Dar, the government seat of the Amhara National Regional State.
The tunnel boring machine digs 24 metres a day with a diametre of 8.1 metres, according to Kifle. Powered by electricity, the machine needed water and air-conditioning to run smoothly underground.
There is a surge shaft incorporated into the design which channels some of the high-pressure water coming from the lake as it reaches the end of the tunnel. Some of this water is directed up through the shaft 20 metres in diametre and 94 metres high. This protects the tunnel walls and turbines from the direct pressure.
The water from the end of the tunnel falls down 275m to four turbines in a powerhouse, each with a capacity of 115mw. These turbines were bought from Italy and Austria at a cost of 80 million Br. The powerhouse has a control room, electromechanical room (where the turbines are), four transformers, as well as service rooms.
Each transformer sends 400kV of power on three lines to the project’s switchyard station, which is aboveground on top of the powerhouse. Only the switchyard and the water inlet can be seen from above.
This power will be transferred to the Bahir Dar substation on 136 electric towers. These towers will all be erected by January 2010, Dawit Belete, supervisor at the powerhouse told Fortune.
The power will proceed from the substation onwards to Sululta, on the outskirts of Addis Abeba, and then to the national grid at Kaliti. Misikir Negash, communication officer at EEPCo, says that the Beles project will add 1,716 rural households to the existing 3,386 in EEPCo’s rural electrification project, in addition to the industrial clients and urban households it will supply.
The water that will leave the turbines will join the three lakes of Johanna, Kasaham and Lamb, all found within a range of 7.3km. The water goes five kilometres further to be used for irrigation, which is why the project has been dubbed a multipurpose one.
The project construction has been running non-stop, 24-hours-a-day, employing 500 workers in three shifts, Abio Ciciotti, site manager at Salini Construction SPA, told Fortune.
“It normally would have taken seven to eight years,” he said.
If the testing goes successfully, the plant will begin formal operation in March 2010. From that time on, the project will serve the country for the next 25 years without any major interruption, Dawit told Fortune.
Gilgel Gibe II and Tekeze, with capacities of 420mW and 300mW respectively are also expected to go fully operational in 2009/10. Together with Beles, which, according to Misikir is the largest project so far, the total national power supply will grow to 2,054mW. When Gilgel Gibe III is completed it will grow further to 3,270mW.