Promoting Beneficial Environmental Effects and Improving Long-Term Utilization Strategies Through IEA-GIA Collaboration

The IEA-GIA provides an opportunity for international collaboration on various aspects of resource development, including environmental issues (Annex 1). Outcomes over the past five years have included a series of workshops, discussion documents, and papers on several topical issues including: protecting and enhancing natural thermal features, minimizing adverse effects from disposal of geothermal fluids and gases, providing policy advice, dealing with induced seismicity, and improving sustainability of geothermal production. With respect to felt induced seismicity, which has been an environmental and social issue associated with EGS projects, particularly in heavily populated areas, a protocol has been prepared on how to deal with the issue pro-actively. By discussion amongst collaborating Annex 1 members it was agreed that strategies to sustain heat and power generation output by successfully managing geothermal fields in the long term are crucial to the future of geothermal. Over a relatively long term (100 years and beyond), these strategies may involve cycles of utilization to allow recovery of depleted reserves from deeper recharge zones. To achieve continuous geothermal generation, this will require exploration and identification of geothermal systems for backup generation during recovery periods. Also, adaptive management of production and injection, by adjusting rates and locations, will be needed to optimize sustainability and utilization of each system. This requires flexibility and surplus capacity to be built in at an early stage and then maintained throughout the stages of development. Comparison of international experience showed that successful reservoir management strategies emphasize environmental balance through avoiding, remedying or mitigating adverse effects and promoting beneficial effects, to receive greater community support. In this regard, international experience in developing environmentallysensitive strategies to promote geothermal production, provides strong role models for future developers.