| Abstract |
Commissioning geothermal power plants is considered a crucial step in the geothermal energy development cycle. It is the last stage prior to commercial operation and it aims at ensuring that all guaranteed system conditions are met. In the year 2015, Kenya Electricity Generating Company (KenGen) PLC, injected 280MW of power into the national grid from geothermal sources after commissioning two power plants namely Olkaria 1 Additional Units (AU) and Olkaria IV. This was considered to be the single largest geothermal power project in the world and in the same year, there was a 65% drop in the cost of electricity fuel component which is the single largest portion in the electricity bills in Kenya. Apart from power stations, the project also entailed other systems in steam gathering, substations and transmission. Due to the complex nature and uniqueness of geothermal projects, various challenges were experienced thus affecting project commissioning timelines. These challenges are failure of glass reinforced plastic pipes, pressure let down station valves and scrubber internals. Additionally, there was excessive pressure drop through the main steam strainers and turbine first stage nozzles which meant that the turbine efficiencies or steam rates did not meet contract requirements. This led to modification of the first stage nozzles and steam strainers. This paper purposes to discuss in detail, commissioning of main plant systems, challenges faced and lessons learned during project commissioning. |