Closed-loop geothermal
Closed-loop geothermal systems (also known as “advanced geothermal systems” or “AGS”) are a type of engineered geothermal energy system containing subsurface working fluid that is heated in a hot rock reservoir without direct contact with rock pores and fractures. Instead, the subsurface working fluid stays inside a closed loop of deeply buried pipes that conduct Earth’s heat. Closed-loop geothermal systems are one of the prominent categories of next-generation geothermal systems in development today.
Like all geothermal systems, closed-loop geothermal systems provide renewable energy, and primarily operate as baseload resources that produce energy at a constant rate. Unlike conventional geothermal energy plants, closed-loop geothermal plants can be placed anywhere in the world, depending only on the depth of the hot rock resource. This type of technology isn't dependent on the permeability or water accessibility of conventional geothermeal.
Closed-loop geothermal projects are under development in the United States, Canada, Japan, and Germany.