Geothermal Binary Power Plant for Lahendong, Indonesia: A German-Indonesian Collaboration Project

Abstract

In addition to the use of high-enthalpy geothermal resources in Indonesia, the development of the existing low-enthalpy resources plays an important role for geothermal exploitation. An efficient exploitation of this lower temperature range can significantly extend the exploitable geothermal potential since the plant capacity at many high-enthalpy fields could be increased and low temperature resources can be used for decentralized energy supply. Even though geothermal low temperature power plants offer a huge potential and have been installed at more than 100 sites world-wide, there are still challenges that prevent their application at Indonesian geothermal sites. In order to successfully demonstrate a geothermal binary power plant in Indonesia, a German-Indonesian collaboration project involving GFZ Potsdam (Germany), the Agency for the Assessment and Application of Technology in Indonesia (BPPT) and Pertamina Geothermal Energy (PGE, Indonesia) has been set-up. The demonstration power plant will be located in Lahendong, North Sulawesi, where it uses hot brine from the separator of existing wet-steam production wells. The power plant cycle will be a subcritical, single-stage Organic Rankine Cycle (ORC) with internal heat recovery and an installed capacity of 550 kWe. The on-site integration is aiming at reliability and flexibility so that this technical concept can be easily implemented also at other sites. The scientific work objectives are directed to the systematic analysis and evaluation of all steps in the technical implementation of a binary power plant at an Indonesian site. The knowledge from planning and operating the Lahendong demonstration power plant will serve to define further optimization and development needs and to transfer the gained experience to other possible locations. Extended process understanding and optimum site integration tailored to Indonesian locations is a prerequisite for the expansion and development of binary power plant technology in the future. The presentation will give an overview on the project course and the project goals.