Methodology of pre-feasibility study for a binary geothermal power plant utilizing moderate-temperature heat resources
The exploitation of medium-low temperature geothermal reservoirs is a potential resource that does not yet have mature commercial technology solutions. This study describes a methodology of pre-feasibility study for a binary geothermal power plant utilizing moderate temperature heat sources . This pre-feasibility study can be a useful tool for decision making processes in the preliminary study. The methodology is applied to an existing geothermal well located in the Taupo Geothermal Zone (TGZ) in New Zealand. Three common working fluids, n-pentane, R245fa and R134a are analyzed. The cycle designs considered are standard (Std) and recuperative (Rec) cycles. The results of the analyses indicate that the Std designs using n-pentane and R245fa are feasible for the geothermal well. The Std design using R245fa is more economical than the design using n-pentane, however the design using R245fa has lower Energy Return on Investment (EROI) than the design using n-pentane. The present methodology can be utilized to estimate pre-feasibility of geothermal wells in the initial stage , reducing risk and indicating potential for further engineering investigations..