Inside the earth is a potentially large heat source that can be used for geothermal energy. One source of this heat and energy is steam or lava that comes out of volcanoes, which can help produce usable electric power in locations where this heat source is close to the earth’s surface.
Another form of geothermal energy can be generated from low-temperature geothermal energy due to the average ambient temperature at that location. This energy is available to everyone with a heat pump system that utilizes the ground temperature just below the surface, which remains around 50 to 60 degrees fahrenheit throughout the year. This system is also known as a ground source heat pump.
A geothermal heat pump utilizes the constant temperature of the ground to bring heat into the home during the winter and return heat to the ground in the summer. The system has pipes that are buried under the ground in a vertical or horizontal manner to create a loop for water to flow. The water is circulated with a pump and a vapor compression refrigeration cycle inside the house to transfer heat between the inside air and water in the loop.
Because the ground temperature is nearly constant all year, the heat pump can efficiently provide both heating in the winter and cooling in the summer from the same system. The Center uses a geothermal heat pump to provide heating and cooling to the NCSU Solar House.