Atmospheric emissions profiles of geothermal energy production to minimise the environmental footprint: an innovative methodological investigation based on LCA approach

The fight against the climate change is the biggest challenge of the 21st century. The keyword in this context is “decarbonisation”: the development and management of an economic system with low Greenhouses Gases emissions. In this thesis, the environmental assessment of power generation technologies exploiting a renewable and environmentally friendly energy source, namely the geothermal energy, is presented. To evaluate the advantages and hot-spots of implementing such technologies the Life Cycle Assessment method was employed as the most powerful analytical tool for environmental sustainability analysis with a life cycle approach. With this method, it is possible to investigate a system with a multi-criteria approach, not limited to climate change only, but overarching a wide portfolio of environmental impact categories and indicators such as acidification, use of fresh water and depletion of natural resources. A rigorous scientific analysis should always be based on high-quality and robust data. Therefore, the atmospheric emissions of all the geothermal plants currently operating in Italy were carefully collected and analysed. In addition to direct emissions information, an extensive work to build the complete Life Cycle inventory of a state-of-the-art geothermal power plant. From the methodological point of view, the application of the Life Cycle Assessment to geothermal power plants allowed to point out a critical aspect method itself. To this purpose, special relevance in this work is given to the results related to the toxicity issue because they are the ones that attract the most public opinion and at the same time are more uncertain and unreliable. To improve the dissemination of LCA results and the diffusion of correct information, an essential step could be the implementation of methodological advances that facilitate the use LCA. In this work the development of simplified LCA models is presented and discussed in terms of the support that can provide both for decision-makers in their function, but also for experienced LCA practitioners.