Small Scale Geothermal Power Plants with Less Than 5.0 Mw Capacity

Abstract

With the current interest in small-scale geothermal power plants for rural local generation and offgrid power, this paper examines five case histones of such small power plants in terms of technology, economic and inhtructure issues. From a technology standpoint ORMAT' has supplied over 200 power modules ranging in size from 0.3 MW to 6.5 MW, either singly as small power plants or in combination as larger power plants. These binary technology based power plant modules operate with geothermal fluids at temperatures of 100?C to 315'C. Power plant modules of this type were installed in the cases considered herein as follows: (a) Tad's Enterprises, Nevada USA, with 2 modules rated at 1.75 MW total; @) 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) Sao Miguel Geothermal No.1, Azores, Pomgal, with 2 modules rated at 5.5 MW total. This presentation details economic, maintenance and resome issues. Conclusions reached are that: (a) small geothermal power projects are technically and economically feasible, with plant and well utilization technologies proven and power costs acceptable, and @) most d the problems in developing and operating these plants relate to availability of financing and maintenance infrastructure.