The U.S. Dept. of Energy selected Utah-based Greenfire Energy for "field evaluations of a low temperature carbon dioxide-based geothermal electric power generation plant. In Phase I, it will set up and initiate seismic monitoring at an existing CO2 production field, and collect and evaluate existing data. In Phase II, it will test several energy recovery techniques in existing shallow wells and the performance of CO2 as a working fluid." The company will receive $2 million from DOE and use CO2 from the St. Johns-Springerville field, under development by Ridgeway Arizona Oil Corp [right].
The project is one of seven announced yesterday. DOE explained the basis of this round of funding:
Low temperature resources are widely available across the country and offer an opportunity to significantly expand the national geothermal portfolio. However, most low temperature geothermal resources are not hot enough to be harnessed through traditional geothermal processes, including dry steam or flash steam power plants, which typically use water at temperatures greater than 360°F (182°C). The projects announced today aim to take advantage of geothermal fluids that won't "flash" on their own for electricity generation, but could be used in binary-cycle power plants. In binary cycle technologies, the water from the geothermal reservoir is used to heat another "working fluid," which is vaporized and used to turn the turbine or generator units.