Innovative Approach for Risk Assessment in Green Field Geothermal Project

Abstract

At present, the worldwide geothermal energy production provides less than 1% of the world’s energy needs but the geothermal resources confined in the first 6 km of the earth’s crust are estimated to be in the fairly above 200 GW of which 50-80 GW are located in Europe. Exploring and developing at large scale untapped hydrothermal resources represent a major challenge for geothermal energy development worldwide. Several workflow processes, procedures and techniques are currently applied to locate and assess the geothermal potential in various geological contexts: sediments, volcanic, granites and metamorphic. Models and tools has been developed to forecast the performance of a green field geothermal project, but many uncertainties determine relevant risks for the investors in all the different phases of the single project and mainly in the exploration phase. The uncertainties are mainly related to the technical and economical performance (e.g. resource characteristics, the efficiency of power conversion systems, energy market conditions) but the environmental sustainability and the social acceptance might represent potential hurdles for the project development. This paper describes an innovative approach for risk assessment and mitigation applied for the exploration of green field geothermal projects. A holistic multi criteria analysis is applied to calculate the risk index of the project based on: resource characteristics a) (e.g. depth, temperature and sustainability along the whole life of the project), b) technological solution for power conversion systems (e.g. electricity and/or heat generation), c) market conditions (e.g. electricity price, tax regimes), d) the environmental and social factors (e.g. air emission, induced seismicity, natural parks). A guideline is proposed for the identification and ranking of the most promising areas suitable for sustainable geothermal project development in Europe.