Life Cycle Environmental Impacts of Geothermal Systems

Abstract

Geothermal energy is increasingly recognized for its potential to reduce greenhouse gas emissions. Studies have shown that air emissions, water consumption, and land use under geothermal electricity generation will have less of an environmental impact than traditional fossil fuel-based electricity generators. However, the environmental impacts of geothermal energy across its life cycle, including the construction of well fields and production facilities, are less well understood. With a potential threefold increase in geothermal electricity generation by 2035, the lifecycle impacts of geothermal technologies must be explored. This paper presents potential impacts and factors associated with construction, drilling, and production activities of enhanced geothermal systems (EGS), hydrothermal binary, hydrothermal flash, and geopressured geothermal systems. Five power plant scenarios were evaluated: a 20-MW EGS plant, a 50 MW EGS plant, a 10-MW binary plant, a 50-MW flash plant, and a 3.6-MW geopressured plant that coproduces natural gas. The impacts associated with these power plant scenarios are compared with those from other electricity generating technologies.