Earth Energy Systems: Environmental effects of direct use of geothermal energy resources

Abstract

The use of Earth Energy Systems (EES) is meeting increasing interest as form of direct use for providing energy and heating for smaller distribution circuits. In this paper we review the potential impacts of direct geothermal energy use on the environment and environmental matters relevant to human health. Three main categories of environmental and human health concerns related to EES are identified: thermogeological; geological and hydrogeological; and water quality and quantity concerns. Particular focus is given to groundwater ecology and water quality. The sustainability of direct use of EES is also considered, and specific attention is given to ecological sustainability and thermal ecological impacts. Consideration for the development of regulations for the implementation of direct use of EES is also discussed.