The KEPCO Research Institute has developed the Molten Carbonate Fuel Cell (MCFC) since 1993. Recently, a 125-kW MCFC system has been operated at the Boryeong thermal power plant in Korea from December 2009 to March 2010. This system is made up of a 125-kW stack, mechanical balance-of-plant (MBOP), and an electrical balance-of-plant (EBOP). The stack has 200 unit cells of which the effective area is about 10,000 cm(2). Especially, MBOP is mainly composed of an ejector and a catalytic combustor which help this system to be supplied with cathode inlet gas using anode tail gas and fresh air. After the pretreatment of this system was performed for about 20 days, an initial load operation was carried out in January 2010. At first, the stack showed an open circuit voltage of 214 V. It produced a maximum power of 120 kW DC. Moreover, this system operated for 3270 h. (C) 2011 Elsevier Ltd. All rights reserved.