Double Well Installation (Geothermal)

There are several installation designs used for geothermal energy, among them, the geothermal double well installation (sometimes referred to as a "doublet"). The first well extracts hot water from a geothermal reservoir. A heat exchanger then transfers the geothermal heat to a ground loop that circulates water through a building's heating pipes. The cooled geothermal water is injected back into the reservoir via the second well. This system prevents geothermal water from being discharged above ground; it contains sodium chloride, sulfides and other salts that can cause corrosion and be harmful to the environment.