Olkaria geothermal plant

Africa's largest Geothermal Power Station, Olkaria generates over 150 Megawatts (MW) into the national grid, with Kenya aiming for 1200 MW by 2018.

The state-of-the-art plant, located on the Great Rift Valley, operates on a single flash plant cycle with steam consumption of 7.5 t/h/MW.

Geothermal power generation requires exploration and drilling for steam generated by the 'hot rocks' of relatively young geological areas to turn the electricity-generating turbines. But high up-front costs and the substantial risks involved in geothermal development have meant only a fraction of the Great Rift Valley's geothermal potential has been exploited.

In 2002 the United Nations Environment Programme (UNEP) began working with the National Power Generation Utility of Kenya (KenGen) on the Joint Geophysical Imaging (JGI) for the Geothermal Reservoir Assessment project, with the aim of lowering geothermal development costs by improving the interpretation of geophysical data, and so reducing the number of expensive, unproductive wells.

Working at KenGen's Olkaria facility, improvements in imaging and interpretation have increased the chances of hitting steam, and made it easier to identify wells of high generation potential.

The UN Secretary-General said: "It is a remarkable story, not just in terms of renewable energy and climate change, but in partnership and development. It is among a growing number of examples of how the United Nations, the World Bank, donor governments and the private sector are supporting forward-looking public policies -policies that can help to reduce poverty and lay the foundations for a truly sustainable future."

Through its sustainable, value-added approach, the Olkaria project has contributed to technology transfer and capacity building through training of KenGen scientists and technicians, and has increased power generation and supply reliability while simultaneously reducing costs and benefiting the environment.

The JGI project improved geophysical data interpretation techniques and provided state-of-the-art equipment for exploration, using Micro Seismic (MEQ) and Magneto Telluric (MT) surveys and analysis to identify promising new drilling sites.

UNEP, with funding from the Global Environment Facility (GEF), contributed US$1 million towards total costs of US$2.7 million. Duke University in North Carolina, United States, collaborated on the project, which has resulted in substantial savings on the proposed development of geothermal resources in Kenya, and there are plans to replicate this in the wider region. In addition, the project has provided sustainable capacity in these advanced techniques at KenGen's Olkaria facility.

The project has already shown its regional potential, with KenGen using its expertise to help Rwanda, Eritrea and Zambia assess and develop their geothermal resources.

A regional project involving numerous partners, including UNEP, has been initiated in six East African countries: Djibouti, Eritrea, Ethiopia, Kenya, Tanzania and Uganda, to tap into the Rift Valley's vast, unexplored geothermal potential.

The African Rift Geothermal (ARGeo) project, supported by UNEP through a GEF contribution of US$17 million, will provide a platform for accelerated geothermal development and investment. Initial estimates are that these investments could lead to close to 900,000 tonnes of CO2 emission savings per year, and well over 17 million tonnes over 20 years. It is expected that these pilot projects will generate additional interest in geothermal technologies and that this sustainable resource will be exploited in many of countries bordering the Rift.