Sinclair Knight Merz was awarded an overall consultancy contract in 1998 as owner’s engineer and project manager for the Olkaria II Geothermal Power Project in Kenya. This involved engineering design and supervision support on five major contracts - power plant, steam field engineering, site civil works, switchyards and transmission lines.
The Olkaria geothermal field is located in Kenya’s Rift Valley about 120 kilometres from Nairobi. The first power plant, Olkaria I, was commissioned between 1981 and 1985, with3 x 15MW machines. Planning for Olkaria II’s 2 x 35MW generators commenced about the same time, with most of the concept design carried out by the early 1990's, and all the wells drilled by 1993.
In the initial phase of the Project, design reviews recommended several important technical changes, with the cost being justified by use of through-life value analysis techniques. These included changing the turbine hall structure from concrete to steel, and the incorporation of more modern building materials. Plant changes included the use of modern canned pumps in lieu of barometric sealing pits, and a change to the type of cooling tower, with this particular item resulting in a significant cost saving to the Client in terms of both the capital cost of the cooling tower and the civil works associated with a smaller footprint.
During the Review of the Steamfield, SKM identified a number of other design changes that added value to the Project. These included:
- Revisions to the steamfield pressure control system and the addition of brine loop seals to avoid brine flashing and carry-over of solids to the turbine
- Revision of the well-pad layout to provide adequate access for separation plant operation, along with space for maintenance and well work-overs.
For further information, contact: Sinclair Knight Merz