Economic Optimization of a CO2-Based EGS Power Plant

CO2-based enhanced geothermal systems (EGSs) have been examined from a reservoir-oriented perspective, and as a result thermodynamic performance is well explored. Economics of the system are still not well understood, however. In this study, the economics of the CO2-based EGS technology is explored for an optimized power plant design and best-available cost estimation data. We demonstrate that near-optimum turbine exhaust pressure can be estimated from surface temperature. We identify that achievable cooling temperature is an important economic site consideration alongside resource temperature. The impact of time required to sufficiently dry the reservoir prior to power generation is also addressed. The role of sequestration as part of CO2-based EGS is also examined, and we conclude that if fluid losses occur, the economic viability of the concept depends strongly on the price associated with CO2.