Geothermal’s potential is practically unlimited, according to advocates and a powerful MIT study, but getting the most out it will require going beyond the conventional practice of using high-temperature water near the surface. To that end, the U.S. Department of Energy announced it is doling out $20 million in grants to companies working on three embryonic geothermal technologies: low temperature fluids; geothermal fluids recovered from oil and gas wells; and highly pressurized geothermal fluids.
The grants are divided among seven companies, and range from $982,000 for ElectraTherm, a Nevada company “seeking to demonstrate the financial and technical viability of producing electricity from heat coproduced in geothermal brine,” to $5 million for Louisiana Geothermal, which is exploiting the possibilities from geopressured fuels—geothermal reservoirs that contain natural gas uneconomical to produce alone, but possibly viable in combination with geothermal energy production.
Four companies will receive between $1.2 million and $2 million to work on low-temperature geothermal fluids. Conventional geothermal uses water at 360 degrees Fahrenheit (182 Celsius) or higher for dry steam or flash steam power plants. The hope is that binary-cycle technologies—in which the extracted lower-temperature water is used to heat a pressurized secondary fluid, which is vaporized to drive a turbine—will make not-so-hot geothermal spots workable. All the companies getting grants in this category are in the West: two in Northern California, one in Nevada and one in Arizona.
These grants are the latest in a long string of such grants under the Energy Department’s Geothermal Technologies Program.