By Keith Breene
If you think of geothermal power having a national home, it is probably the frozen expanse of Iceland or perhaps the volcanic springs of New Zealand. Both countries, on opposite sides of the world, owe their famously prolific geological activity to their position on shifting tectonic plates.
In fact, the region emerging as the world's leading geothermal power is thousands of miles away from both of these countries, in the verdant hills of East Africa.
By Keith Breene
Kenya's Maasai people have long been aware of the awesome power of the earth in the area around Hell's Gate National Park. And now the region is experiencing interest from much further afield - in fact it is considered to be one of the most exciting geothermal areas on the planet.
According to Kenya's electricity generating utility KenGen, geothermal power has now overtaken hydropower as the country's top energy source.
The benefits of geothermal power are extensive. It is sustainable, producing none of the greenhouses gasses emitted by fossil fuels. It is also much more consistent in its generation capacity than other renewables.
Geothermal energy comes from a mixture of water and steam under pressure drawn from nearly 2km beneath the earth. The pressure and heat separates water vapour from water when it rises to the surface which turns the turbines and produces electricity.
Hydroelectric power has been the mainstay of Kenya's power generation industry for a long time. But rivers are vulnerable to drought. Hydroelectric energy generators can run at as little as 58% of their installed capacity.
Geothermal, however, consistently delivers almost full capacity. Geothermal sources currently account for one-third of Kenya's installed capacity but provide more than half of the energy generated due to their high energy yield and stability against weather variations.
The Kenyan government has made increasing power production one of its highest priorities.
KenGen has drilled 137 geothermal wells since 2007 and eight rigs are in operation at the Olkaria steam fields. The utility has ordered two sets of 80 MW steam turbines from Mitsubishi Hitachi Power Systems (MHPS), a joint venture of Mitsubishi Heavy Industries and Hitachi, which are due to go online in 2019.
MHPS has already supplied six sets of turbines for the Olkaria I and II geothermal power plants with a total output of 150 MW.
The Kenyan government has set the ambitious target of producing a total of 5,000 MW of energy by 2030, enough for millions of homes. The World Bank estimates that geothermal energy from the Rift Valley could eventually power 150 million homes.
Geothermal energy is not only securing Kenya's energy future, it is also an important source of employment. Kenya has benefitted from UN funding for training geothermal engineers, and KenGen employees receive external training, for example in Iceland, as well as being taught locally. There is also a geothermal postgraduate course at Kimathi University in Kenya.
The United Nations sees Kenya as an international centre of excellence in geothermal power and recently ran a training course for engineers from 16 African countries there.
Other growing countries for geothermal power in the Rift Valley area include Ethiopia, Tanzania, Rwanda and Uganda, all of which are looking to expand their capacity.
According to the Geothermal Energy Association, currently there are new geothermal power projects under development in 23 countries, which will generate over 2,000 MW of power when complete.
Kenya's industry is already world-leading but the future holds the promise of much greater capacity combined with a highly developed regional centre of expertise. The rest of Africa, and the rest of the world, will learn from Kenya's experience.