KenGen has called for expression of interest for feasibility study on binary power generation from brine. The company intends to start producing additional power by utilizing Geothermal Binary Power Cycle technology.

The company’s geothermal plants, Olkaria I & II run on single flash condensing turbines which produce brine. The brine produced by the interconnected wells is currently re-injected while still at high temperatures (above 160°C) which wastes significant amount of usable energy.A total of 55 production wells are currently connected to Olkaria I &II power plants.

The wells produce 2-phase geothermal fluid which is then separated at the separation stations located within the geothermal fields. The separated steam is piped to the power plants whereas most of the separated brine is piped to the hot re-injection wells within the production area. At Olkaria I, most of the separated brine is currently disposed into open drains.

In total, the wells produce an average of 1,000 tonnes per hour of brine at separation pressures of between 6 and 9 bar and corresponding temperatures of between 155 and 180°C. Currently, the hot brine is re-injected or disposed into open drains thus underutilizing the available energy. The enormous heat contained in the brine can be extracted for additional power generation.

With an installed capacity of 1,232.5 mega watts of electricity, KenGen is the country’s largest power producer marking 72 per cent of national capacity. The company is currently installing two additional geothermal power plants with a total installed capacity of 280MW.

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