Saturday, 07 June 2008
Kaleyesus Bekele
After the introduction of power shading, the sales of generators, lamps and candles have boomed. Lamps are sold on the streets of Addis Baba and the sound of generators is heard in every nook and corner. Unable to meet the growing electric power demand, coupled with the failed belg rains, the Ethiopian Electric Power Corporation (EEPCo) introduced a power rationing program almost two month ago. According to EEPCo, the country’s power demand had increased by 15 percent.
To mitigate the problem officials of EEPCo and the Ministry of Mines and Energy (MME) are working together day and night. Currently, EEPCo’s maximum electric generating capacity is 814 MW, 80 percent of it hydro and 20 percent geothermal and thermal. However, due to various reasons, including water shortage, the corporation generates only 600 to 700 MW. EEPCo is undertaking massive hydro-power projects. Tekeze( 300 MW), Gibe II (420 MW), Beles(460 MW), Gibe III (1870 MW) and Fincha Amenti Neshe (100MW).
The construction of Tekeze is expected to be finalized in August. The first unit will start generation in September, if everything goes according to schedule. It is also to construct a wind turbine farm which can generate 120 MW near Mekelle, Adama(Nazareth) and Gondar towns. The corporation plans to construct more than ten hydropower plants. The feasibility study of Gibe IV has been finalized. Gibe IV will have the capacity to generate 2000 MW.
Some 250 km south of Addis Ababa 2, 820 people from 30 countries of different profession are working twenty four-hours on a 420 MW hydropower project, Gibe II. Two thousand and one hundred of them are Ethiopians and 720 are expatriates. Engineers, geologists, construction experts, technicians and other professionals are laboring to finalize the project.
After inaugurating the 184 MW Gibe I hydro-power plant in 2004 the Ethiopian Electric Power Corporation launched the construction of Gibe II. The power project lies on an ever green mountain and gorge in the Sokoru locality between Oromia and the Southern Nations, Nationalities and Peoples Regional states. Because of the project, 80 km of asphalt and all-weather road that connects the two regional state has been constructed.
The very idea of the project is to take the water that comes out of Gibe I power house and to divert the natural course of the river and take it to Gibe II power house through a 25.8 km tunnel. The Gibe II would use the water that come from from Gibe I so there is no need to build another dam. Semegnew Bekele, project coordinator of Gilgel Gibe II, said that the water head difference would be 490.m. “What makes Gibe II different is that it does not have its own dam. It uses the water that comes from Gibe II,” Semegnew said. The water that comes out of the tunnel would run down a hill in two big pipes what they call penstocks, into a power house where there are four turbines each of which will have a capacity to generate 105 MW.
An agreement has been signed between EEPCo and the contractor, Salini Costruttori S.P.A, the Italian construction company that built Gibe one dam, in April 2004 for all the civil work of Gibe II. Work on the project commenced in June 2004. Under Salini, there are three specialist companies, namely SELI, an Italian company, Voith Siemens, German company, and ATB, an Italian company. SELI has been drilling and building the tunnel and Voith Siemens undertaking the hydro mechanical work.
The total cost of the project is 5.2 billion birr. The Italian government provided a soft loan of 220 million euros for the hydro-power project and the European Investment Bank conferred 50 million euros. The balance is covered by the Ethiopian government.
According to Semegnew, ninety percent the work has been finalized. The inlet, the penstock, and power house have been built. The turbines and the power controlling machines are installed. Of the 25.8 km tunnel, 17.1 km has been drilled and built.
SELI uses two tunnel-boring machines (TBM), drilling on both side of the mountain. The TBM is 240 long and the drilling head’s diameter is seven meters. The drilling gear is made of diamond. The plan was to drill both side of the mountain with TBM 1 and TBM 2 from west and east direction. Work on the east side is progressing. TBM 2 drilled at least 13 km. However, TBM 1, which was drilling the tunnel near the inlet, has encountered a serious problem.
The TBM 1 has been drilling the rocky mountain but after it drilled four km it came across an unconsolidated layer (lose land). The drillers discovered a huge hole filled with mud that started to flow to the tunnel. First they tried to excavate the mud and to cover the area with concrete. But all was in vain. The machine was unable to proceed with the drilling because of the lose earth and the mud inflow. Highly trained and experienced soil experts were hired to solve the problem but to no avail. It has been a year since TBM 1 ceased operation. SELI dismantled the machine for maintenance. It took SELI three months to dismantle the machine. And this week they will start to assemble the machine. According to officials of SELI, it would take them a month to assemble the machine.
Reliable sources told The Reporter that a decision has been made to divert the direction of the tunnel to avoid the lose earth. So now the contractor, SELI, is preparing to resume the drilling in a new direction. “ The idea to use two TBMs was a clever decision by the management of EEPCo,” says Semegnew. “ Though one of the TBM ceased operation the other one is still running. If there was only one it would have been worse,” he added.
The original plan was to finalize the construction this month. However, because of the problems this could not be realized. Officials of EEPCo hope to complete the work by March next year. But some experts fear that it could take a year to finalize the work on the project.
The water levels in the dams were lowest in the past several years. Getnet Bekele, head of Gilgel Gibe I, told The Reporter that the country’s energy demand has shown a sharp increase. In 2004-2005 Gibe I generated 798 million kWh, in 2005-2006 816 million kWh in 935 million kWh and in eight months this year it generated 753 million kWh. Gibe I has three turbines with the capacity to generate 184 MW. But due to shortage of water most of the time it only runs one of the generators. However, since last week water run-offs started flowing to Gibe I dam. In the past few days the water height has shown a five cm increase in every 24 hour. And last week the engineers working at Gibe I and Gibe II were delighted with the coming of the run-offs.
“We appreciate the management of EEPCo, the board and Minster of MME for their leadership and follow up,” said Semegnew.
With a population of eighty million, the majority of Ethiopians do not have access to electricity. At the moment, access to electricity is about 22 percent. Only 1,800 towns are electrified from a total of 7,000 rural towns and villages. The Ethiopian Electric Power Corporation (EEPCo) has 1,396,000 customers, 40 percent of them in Addis Ababa. Ninety-five percent of the customers are households and the rest are members of the industrial and service sector. However, the industrial and service sector which accounts for only five percent of the number of customers consumes 69 percent of the electric power.
Per-capita energy consumption is about 25 kWh per year, 500 kWh is considered the average minimum level of consumption per capita for reasonable quality of life. As the majority of the population does not have access to electricity bio-mass is widely used. The use of traditional fuel such as firewood is aggravating soil erosion and habitat destruction.
The government has launched a universal electricity access program (UEAP) to be implemented by EEPCo with the view to enhance the access to fifty percent within five years. At the moment, EEPCo’s maximum electric generating capacity is 814 MW, 80 percent hydro and 20 percent geothermal and thermal. However, because of various reasons, including water shortage, the corporation generates only 600 to 700 MW. At the moment the power deficit is 80 MW.
