Clemson Engineers Work Towards Using “Waste” in a Geothermal Heat Pump System

Clemson engineers Ron Falta and Fred Molz have received a $991,000 grant from the U.S. Department of Defense to research the potential for a Subsurface Thermal Energy Storage (STES) system that could be even more economical and energy efficient than current geothermal heat pumps.

The STES system utilizes much of the same technology used in a conventional geothermal heat pump, relying on the earth’s ability to store heat. The STES system would use energy from below the earth’s surface to heat and cool buildings in an economical and energy efficient manner.

The primary difference between the STES system project and the current energy efficient heat pumps is the use of “waste” energy as opposed to the energy already stored in the ground. The pilot project is set to take place at one of five potential military bases and the system will be retrofitted into an existing building in order to prove is functionality.

What is “Waste Energy”?

The waste energy the project plans to use will take advantage of heat already produced by power plants or solar collectors. The system will take heat produced by power plants or solar panel collectors and store it in the ground. The stored heat will create an artificial hot zone which can be used to heat a structure in the winter. During the colder months the STES system will take the cold outside air and store it below the earth’s surface to create an artificial cold zone. This stored air can then be used to cool a home in the summer.

Currently, while they are one of the most efficient sources of energy, geothermal heat pumps require electricity to heat up the underground air and move the coolant through the underground piping. The STES system hopes to even further reduce this energy needed by storing hot and cold air.

“This technology has the potential to greatly reduce energy costs and greatly reduce carbon emissions,” said Falta, a professor in Clemson’s environmental engineering and Earth sciences department. “At the same time, it allows for the integration of renewable energy into the infrastructure of the base, and it provides a clear path for reducing base carbon emissions and carbon footprint.”

This four-year project could greatly benefit the Department of Defense who currently spends approximately $3.5 billion a year on energy, a majority of which is used to heat and cool base buildings.

Geothermal Heat Pumps Still a Top Alternative Energy Solution

While the STES project could potentially have great implications for future heating and cooling needs, the current technology used in geothermal heat pumps is a solution that can be implemented now. Geothermal heat pumps or over 400% efficient, can save you up to 70% on your cooling costs, and are a top source of renewable energy. (Check out our other articles about the efficiency and cost benefits of geothermal heat pumps). Until these new technologies are tested and proven, consider a geothermal heat pump to begin reducing your carbon footprint now.