The International Energy Agency (IEA) has identified a water dependency inside Kenya's steadiest power source. In its National Climate Resilience Assessment for Kenya, published September 25, the agency reports that four Olkaria-based geothermal plants, together holding nearly half of the country's geothermal capacity, draw cooling water from Lake Naivasha in Nakuru County. Geothermal supplied 43% of Kenya's electricity in 2024.
Energy managers weighing East African supply usually judge a geothermal project by its reservoir, which can deliver steam for decades. The cooling water is a separate matter. At Olkaria it comes from a lake shared with flower farms, towns and wildlife. In parts of East Africa, weak grid capacity already limits where factories can expand, so any strain on dependable generation carries weight beyond the plant fence.
Wet Cooling Towers Keep Kenyan Geothermal Output Steady but Tie It to Water
Most Kenyan geothermal plants cool with wet towers, according to the IEA. The design holds output steady when air temperatures swing, and it makes generation dependent on water supply. Air cooling removes most of that draw but brings its own penalty. The IEA notes that air-cooled plants such as Olkaria III can lose up to 50% of output when temperatures climb above 86°F (30°C).
That estimate traces to a 2002 conference paper from the National Renewable Energy Laboratory (NREL), which modeled an air-cooled plant in the western United States and tested four ways to add limited evaporative cooling. Spraying water directly onto condenser tubes paid back fastest. The authors also warned that the method invites scaling and corrosion. The study modeled one American plant and says nothing specific about Kenya. Still, the tradeoff it describes is common to thermal generation, where the choice of technology largely decides how much water a power system consumes.
Lake Naivasha Water Use Has Been a Planning Issue Since at Least 2000
Competition for the lake is long documented. An August 2000 environmental impact assessment for Olkaria III, published by the World Bank Group's Multilateral Investment Guarantee Agency (MIGA), named horticulture, tourism, fishing, livestock and power generation among its users. It estimated that the ten largest abstractors drew about 60 million cubic meters a year and called for the project to meter its lake water. Those findings are 26 years old and say nothing about current lake levels.
Environmental assessments cited by the IEA recommend that operators prepare contingency plans for alternative water sources and work with the lake management committee on abstraction. Neither requires new technology. Industrial operators elsewhere are reaching similar conclusions, and water supply now ranks alongside power and labor in site selection for many of them.
Geothermal Output Rose 46% in Early 2023 as Kenyan Hydropower Fell
During the last drought, the fleet proved its value. Geothermal generation climbed 46% in the first months of 2023 to offset lost hydroelectricity, the IEA reports. First-quarter figures published by trade outlet ThinkGeoEnergy put geothermal generation at about 1,506 gigawatt-hours (GWh), up from roughly 1,025 GWh a year earlier, while hydropower fell about 47%.
Kenya keeps adding capacity. Another 35 megawatts (MW) came online in March 2026, and the IEA lists the 300 MW Baringo-Silali-Paka project as expected by 2028. The IEA does not say how the new plants will be cooled. Operators have also not published their measured withdrawals from Lake Naivasha, and that data would show how much of the fleet's drought performance depends on the lake.
