Improving Geothermal Power Plant Performance with Topping and Bottoming Cycles, Case Histories in Iceland, New Xealand and the Philippines

Abstract

In many cases, additional generating capacity may be obtained in a cost effective manner by re-powering existing geothermal power plants utilizing otherwise-untapped geothermal energy, without drilling additional wells. Often this repowering also provides concommittant environmental benefits. This presentation examines several repowering applications, including the 9.1MW exhaust steam recovery binary power plant at Svartsengi in Iceland, the 6.4 MW brine recovery binary power plant at Kawerau in New Zealand and the Leyte geothermal power plant optimization project. The four (4) Leyte optimization plants added a total of 64 MW of geothermal power and improved environmental and power plant operating conditions, without any additional well field costs. With geothermal power plant owners and operators concerned with costs and competition, increasing plant output by re-powering is a highly desirable and cost effective option.