History and Performance of the 125 MW Upper Mahiao Geothermal Power Plant

Abstract

The 125 MW Upper Mahiao power plant, the first geothermal power project to be financed under a Build-Own-Operate-and-Transfe(rB OOT) arrangement in the Philippines, will consequently be the first of sx such BOOT projecfs fo be transferred to PNOC-EDCi n June 2006. Ih,'s plant uses ORMAT's environmentally benign binary cycle based steam/binary combined cycle technology and is both the largest such Geothermal Combined Cycle Unit (GCCU) plant in the world, as well as the largest geothermal power plant utilizing air-cooled condensers. The ORMAT-designed and constructed plant, owned and operated by CE Cebu, was developed under a fast-track program, with some two years from the April 1994 contract signing through design, engineering, construction and start-up, and has operated at an average plant availability of over 97% and surpassed ds performance commitmenfs. The plant's almost 10 years of operation has proven the high reliability of the GCCU system and ,fs contribution to the long-term sustainability of the reservoir by dis enabling 100% reinjection for mass balance and pressure support.