FEASIBILITY ASSESSMENT FOR ORC GENERATION SYSTEM DEVELOPMENT USING LOW TEMPERATURE GEOTHERMAL WATER

摘要

Since around 70 °C of geothermal water exists in Seokmo-do of Republic of Korea, this study is to assess the feasibility of electricity generation by utilizing ORC system, and the pertinent economic impact. It is generally believed that economic feasibility can be secured only when the source of geothermal water is above 100 °C in order to generate electricity by operating ORC system. However, there was an exceptional case that ORC system was commercialized by Pratt-Whitney for around 70 °C of geothermal water in the hot springs of Chena, Alaska. The annual average temperature in the hot springs of Chena, Alaska is approximately 1 °C whereas that of Seokmo-do is around 11 °C, which makes 10 °C of annual average temperature difference in operational environment between the two. Thus, the 2 phases of absorption refrigerating machine is considered for the ORC generation system. With establishing ORC system in consideration of operational environment, the feasibility of the development of ORC system in Seokmo-do is assessed by performance analysis and economic feasibility. As a result of the assessment, it is identified that the economic feasibility can be secured if the price of electricity is over $0.42/kWh same as that of photovoltaic generation as an incentive of the RPS program granted by the Korean government.