Life cycle assessment of atmospheric emission profiles of the Italian geothermal power plants

Abstract After nearly a decade of only small development in capacity in deep geothermal sector in Europe, in recent years a resurgence of interest in geothermal power and the use of innovative technologies to increase and better exploit geo-thermoelectric generation has stolen the limelight from the scientific community. Differently from other types of energy sources, the environmental impacts determined by geothermal exploitation are extremely dependent on the geographical location. Life Cycle Assessment offers a powerful methodological approach for the investigation of the environmental footprint of power generation systems. Focusing on an unprecedented system-modelling approach for the investigation of an environmental impacts analysis of geo-thermoelectric activity in the Tuscany Region, Italy, in this work we perform a comprehensive environmental impact assessment for the calculation of atmospheric emissions profiles connected with the operational phase of the power plants. A clustering of all the geothermal installations in operation nowadays is performed by considering geographical representativeness This allows the identification of regional geothermal subareas. Moreover, an extensive data processing analysis is implemented with the aim of reconciling the great variability found among data collected. Results demonstrate that the efforts undertaken by the operator of the geothermal power plants to limit the impact of emissions, through abatement systems like AMIS, are quite effective. Indeed, in areas where mercury and ammonia concentration in fluids constitute a problem to deal with, nowadays the emissive patterns result comparable to the other ones. Notwithstanding, mercury and ammonia emissions, mainly emitted through the cooling towers, still represent a critical problem for all the geothermal fields. On the basis of our findings we conclude that potential chemical interactions and environmental impacts related to the variety of the compounds emitted should be object of future research and a further effort to minimize them.