Beneath our feet lies a source of geothermal heat that can be tapped to provide heating and cooling to both residential and commercial buildings, manufacturing processes, greenhouses and aquaculture ponds. Deep direct-use (DDU) systems are an emerging technology area in the geothermal sector that draw on lower temperature geothermal resources.
Deeper than geothermal heat pumps and other conventional direct-use systems, DDU is deployable at a similar temperature range—between 100 degrees Fahrenheit and 300 degrees Fahrenheit —but at a much larger scale. DDU maximizes system efficiencies and return on investment. This new technology could result in large-scale, low-temperature geothermal applications that create greater opportunities for geothermal resource development throughout the U.S.
The U.S. Department of Energy is providing up to $4 million, subject to congressional appropriations, for research and development projects led by the private sector, universities and national labs to pursue feasibility studies of large-scale DDU systems.
As highly efficient systems, geothermal DDU operations extract the most energy possible from the local geothermal resource. Rather than using geothermal heat to produce electricity, DDU uses hot fluids from underground to directly heat and cool facilities. Directly using geothermal energy in homes and commercial operations can be much less expensive over the long run than traditional energy sources because it reduces electricity demand and replaces the need for electric-driven heating and cooling appliances.
In energy intensive sectors, including military installations and medium-to-large scale commercial buildings and manufacturing facilities, DDU offers great opportunities to significantly expand the impact and reach of geothermal energy.
Although direct-use is the oldest, most versatile and most prevalent form of geothermal energy, deep direct-use systems have not been developed in the U.S. because technical, cost and institutional barriers remain. The Energy Department’s new funding opportunity could help unlock these lower temperature geothermal applications for near-term deployment and support the goals of improving energy efficiency in manufacturing and reducing the energy bills of businesses and institutions nationwide.
This article was originally published by the U.S. Department of Energy in the public domain.