Case Histories of Small Scale Geothermal Power Plants

Abstract

A large number of rural and remote areas have local geothermal resource areas capable of supporting electrical power generation. Indeed the recent report by the GEA (Gawell et all, 1999) indicates that as many as 39 countries have geothermal resources capable of supplying 100% of these countries needs. Though these geothermal areas may not be connected to the national power grids, with local smallscale geothermal power generation neighboring communities can enjoy the benefits of cost effective and sustainable electricity supply. The current interest in small-scale geothermal power plants for rural local generation and off grid power warrants examining case histories of such small power plants in terms of technology, economic and infrastructure issues. The cases considered herein are: (a) Tadís Enterprises, Nevada USA, with 2 modules rated at 1.75 MW total; (b) Empire Geothermal, Nevada USA, with 4 modules rated at 4.8 MW total; (c) EGAT Fang Geothermal, Thailand, with one module rated at 300 kW; (d) NAGQU geothermal, Tibet PRC, with one module rated at 1.3 MW and (e) S„o Miguel Geothermal No.1, Azores, Portugal, with 2 modules rated at 5.5 MW total, and subsequent expansion to 14 MW. In this presentation we have considered the economic, operational and geothermal resource issues. The conclusions are that: (a) small geothermal power projects are technically and economically feasible, with power plant and well utilization technologies that are proven, (b) power costs are acceptable, and (c) most of the problems in developing and operating more such plants relate to availability of financing and maintenance infrastructure.