Lesson learned – The operation of the pilot scale geothermal power plant 3MW – Kamojang, Indonesia

Abstract

BPPT has developed and operated a 3 MW Geothermal Power Plant (GPP) of a condensing type technology in Kamojang, West Java - Indonesia, which is the first prototype GPP manufactured by Indonesian companies. The BPPT’s pilot plant was designed based on the geothermal steam field of the KMJ-68 well. The pilot plant becomes an early stage for developing wellhead type GPP in Indonesia. The wellhead GPP can meet with the capability of local manufacturers in the turbine and generator. The local content of BPPT’s pilot plant has reached 63.14 %. This paper discusses the design of Process Flow Diagrams (PFD), performance, and reliability of this plant during continuous synchronous testing to the 20 kV local power grid on November 21–25, 2019. This test is intended to fulfill the requirements to get a Certificate of Operation (SLO). The proposed SLO is for operation at a nominal power of 2 MW considering the limited capacity of the KMJ 68 well. As a technical requirement to obtain the SLO referred to, the plant must be operated continuously for 3 x 24 h in a power range of 1.8–2.2 MW. The utilization efficiency of the GPP was 29 %, which quite good considering dry steam geo-fluids condition. The specific steam consumption (SSC) achieved 14 kg/kWh. The plant still has an opportunity for improving efficiency by reducing the pressure loss in the steam strainer, increasing the condenser vacuum, and improving the turbine design and fabrication. The important aim in this testing was that the plant has operated by following the electricity demand fluctuation in the 20 kV PLN grid. This testing progress becomes a promising stage for the development of GPP’s equipment with local manufactures.