Supply Characterization of Hydro-geothermal Resources in the Western U.s

Efforts to characterize geothermal supply have long been focused on the aspect of power generation [Petty, et al., 1992], [Petty, et al., 2007], and [Augustine, et al., 2010]. This paper focuses on an approach to characterize the supply curve of hydrogeothermal energy that can be used for direct use in the United States. It aims to compensate for the absence of research on thermal uses and provides a levelized cost estimation of geothermal direct utilization, especially district heating. A cost model for geothermal district heating projects, which is a function of geothermal gradient and population density, is developed. The model calculates the levelized cost, the capital cost, as well as the operation and maintenance cost. As expected, the resulting supply curve indicates that economicallyviable sites for geothermal district heating are concentrated in western U.S. It also demonstrates that high geothermal gradient and high population density could significantly lower the levelized costs of directuse geothermal. The paper provides a procedure for future supply characterization research of EGS resources.