KenGen owns four geothermal power stations, Olkaria I, Olkaria II, Olkaria IV and Olkaria I unit 4 & 5. In addition to the Power stations, KenGen own fifteen wellheads generation plants one at Eburru and fourteen at Olkaria.
The Geothermal Power Plants have a combined generation capacity of 533.5MW.
Olkaria I Power Station
Olkaria I Power Station was the first geothermal power plant in Africa. The 45 MW plant was commissioned in three phases and has three units each generating 15MW of electricity. The first unit was commissioned in June 1981, the second and third units in November 1982 and March 1985, respectively.
A total of 33 wells were drilled for the station. Thirty-one of these are currently connected to the power station while two of these are retired. One of which is currently being used for hot re-injection. The turbines are direct condensing 4-stage running with an inlet steam pressure of 5 bars at temperatures of 152oC and steam consumption of 9.2 t/h/MW. The plant has had an average availability factor of over 95 per cent from commissioning. The power generated is connected to the national grid via a 132KV-transmission line.
Olkaria II Power Station
Located in the North Eastern sector of the greater Olkaria Geothermal field and commissioned in 2003, Olkaria II Power Station generates 105 MW. Initially, the power plant generated 70 MW from two units of 35 MW each. Later a third 35 MW unit was added. Construction of the third unit commenced in 2009 and was completed in May 2010, bringing the total generation capacity to 105 MW.
Wells were drilled between 1986 and 1993 but construction of the power plant was delayed until the year 2000 when funds became available. The project was co-financed by the World Bank, the European Investment Bank, KfW of Germany and KenGen. Designed and constructed with an advantage of newer technology, this state- of- the- art plant is highly efficient in steam utilization. It works on single flash plant cycle with a steam consumption of 7.5 t/h/MW. The turbines are single flow six stage condensing with direct contact spray jet condenser. The power generated is transmitted to the national grid via 220 KV double circuit line.
Olkaria I Unit 4 & 5 and Olkaria IV Power Station
Olkaria IV and Olkaria I unit 4 & 5 each generating 140 MW were commissioned in December 2014 and February 2015 respectively. This is the country’s largest Geothermal Power Project. Olkaria I unit 4 & 5 is located at Olkaria East of the Olkaria geothermal field whereas Olkaria IV is at the Olkaria domes field.
The projects were funded by KenGen and bilateral partners such as World Bank, Japan International Cooperation Agency (JICA), European Investment Agency (EIB), Africa Development Bank and KfW.