How can geothermal hot water be used to heat greenhouses and soil?

Geothermal hot water is utilized for heating greenhouses and soil through a process known as direct-use application. Unlike geothermal heat pumps, which rely on the stable, moderate temperatures of shallow ground, direct-use applications harness low-temperature geothermal resources—typically ranging from 50 to 150 °C (122 to 302 °F)—found deep underground.12

In these systems, the hot water is often circulated directly through the heating infrastructure of the greenhouse. In cases where the geothermal fluid contains problematic minerals or gases, such as hydrogen sulfide, a heat exchanger is employed to transfer the thermal energy to a secondary fluid or air system without allowing the geothermal water to come into direct contact with the greenhouse environment. This method provides a reliable, sustainable heat source that maintains optimal growing temperatures for plants and soil, regardless of external weather conditions.1