Review of Environmental and Social Aspects and Best-Practice Mitigation Measures from an IEA-Geothermal Perspective

The technical collaboration program of IEA Geothermal, has, since 1997, through its Working Group 1, undertaken cooperative research studies on environmental and social issues relevant to advancing development of new renewable geothermal resources and sustaining production from existing geothermal systems, by using state-of-the-art technology and best-practice procedures. The goals of the group are: 1) to encourage the sustainable development of geothermal energy resources in an economic and environmentally responsible manner; 2) to quantify and balance any adverse and beneficial impacts that geothermal energy development may have on the environment, and 3) to identify ways of avoiding, remedying or mitigating adverse effects. Tasks include: a) addressing impacts on natural features by monitoring surface thermal feature and ecosystem changes and devising techniques to avoid or mitigate adverse impacts, while encouraging beneficial effects; b) rectifying discharge and reinjection problems, including gas emissions (CO2 & H2S), chemical contamination of water, subsidence, scaling and corrosion, treatment options, and reinjection strategies; c) developing methods of impact mitigation and environmental procedures through an analysis of issues, procedures, efficient policies, protocols, effective compliance, and successful strategies to address social and environmental effects; d) sustaining utilisation by undertaking long-term reservoir simulations, optimizing future operational strategies, improving recharge factors and recovery times, improving reservoir performance, and applying holistic sustainability protocol indicators. This paper summarizes the recent outcomes of that collaboration amongst eight participating countries: Australia, Iceland, Italy, Japan, New Zealand, Norway, Switzerland and the United States. One highlight has been the raising of international awareness of successful mitigation schemes and beneficial environmental or social outcomes.