Groundwater Thermal Storage for home energy savings
Cooling and heating costs in homes can be reduced by tapping underground water reservoirs. This approach is supported by findings from a national laboratory focused on energy science. About 12 percent of global energy demand goes toward heating and cooling buildings. As governments in developed nations aim to lower electricity use, researchers are exploring how natural systems and existing resources can support the same goals once served by machines alone. In this context, Eitidi Perera and colleagues proposed using the thermal mass of groundwater to smooth daily temperature swings and lessen energy use for both heating and cooling in residential spaces.
One researcher explained that such a system has the potential to store a large amount of energy for extended periods. The result could mean that energy requirements for heating and cooling during extreme heat or cold would be met without placing additional load on the electrical grid, enhancing the resilience and flexibility of a city’s energy infrastructure.
The concept involves pumping water from underground reservoirs to the surface for heating in the warm season or cooling in the cold season, and then returning it underground. Soil acts as a strong insulator, helping to maintain water temperature across seasons. The method is particularly suited to regions with substantial seasonal temperature variation. For safety, it is advised to use deep underground reservoirs where groundwater remains isolated from drinking water sources and to avoid introducing chemicals. This point is emphasized by the researchers as essential for environmental protection.
In a computer simulation of a hypothetical Chicago neighborhood comprising 58 two-story homes, the system was shown to reduce external energy use from power plants by about 40 percent while maintaining the same level of indoor heating and cooling performance.