The Energy Department is supporting geothermal exploration at lower temperatures, thanks to a technology breakthrough that allows geothermal energy to be produced at temperatures below the boiling point (212 degrees Fahrenheit).This innovation increases the development potential of geothermal sites worldwide. The exciting news comes from Energy Department-funded research and development at Chena Hot Springs, a promising hot spot in Alaska for onsite geothermal energy production among many in the state’s Native American lands.

Geothermal innovations such as these has shown great promise and opportunity for years. Yet despite the rich resource potential there, geothermal heat at lower temperatures could not be tapped until technology was made available to generate electricity from geothermal brine.

While traditional geothermal technology requires 360+ degrees Fahrenheit sources that can be difficult to find and costly to develop, low temperature geothermal technology makes it possible to accesses resources as low as 165°F. The new process could be a game-changer, unfolding a bigger piece of the U.S. map for geothermal industry.

Here’s how it works. A binary process mixes geothermal brine with a working fluid that has a lower boiling point than water. This fluid is compressed into steam to turn a turbine and generate electricity.

In 2006, the Chena Hot Springs plant in Alaska set the record for the lowest-temperature production at 165 degrees Fahrenheit – and still holds it today. Chena’s 400 kW plant was the first low temperature geothermal plant in the world, enabling Chena Hot Springs to reduce the cost of power from $0.30 per kWh to $0.05 per kWh and displacing costly diesel fuel as the primary energy source. 

Geothermal innovations such as this offer a myriad of benefits to Alaska, where off-grid energy demands require residents to use diesel, coals, wood, and other carbon-based forms of energy to power their homes. To learn more about this story and how low-temperature resources are changing geothermal energy, see this short informational video about the Pilgrim Hot Springs project by a group called Frontier Scientists – Diesel Off, Geothermal On. 

The Geothermal Technologies Office (GTO) researches, develops, and validates innovative and cost-competitive technologies and tools to locate, access, and develop geothermal resources in the United States.

The Office of Energy Efficiency and Renewable Energy (EERE) success stories highlight the positive impact of its work with businesses, industry partners, universities, research labs, and other entities.