Geothermal Atlas for Africa Project (GAA): steps to outline the maps of engineering and social sustainability of geothermal resources.

Geothermal Atlas for Africa (GAA) is one of the LEAP-RE projects aimed at developing a geothermal atlas for Africa on different scales, dealing with all topics related to geothermal energy, thanks to the cooperation of many expert partners from different scientific sectors. The main aspects are those concerning geoscientific, engineering, and sociology. The geoscientific aspects, quite prevalent in the first year of GAA, are treated by Jolie et al. (2022) in a separate manuscript. In this work, the local scale engineering and socio-economic aspects related to the sustainable use of the available geothermal resources are discussed. The first relevant achievement of Engineering science (Task 9.2) is a simulation tool to assess the optimal technologies based on geothermal resource type. The potential utilization of medium and high enthalpy resources for power generation has been assessed. To do this, a calculation model was developed on the basis of the characteristics of the geothermal resource and provides a selection of the most suitable power plant technologies and related preliminary sizing. The model is able to incorporate not only the optimized thermodynamic performance of flash and/or ORC binary cycles, but also the minimization of economic (LCOE) and environmental costs (LCA-single score). With regards to the social aspects (Task 9.3), a desk research was performed on the African context in order to address the main challenges related to the economic, social, and environmental of geothermal stand alone plants, looking for the ones managed by or with an high involvement of local communities. The desk research will allow identification of variables used by the communities to maximize the economic, environmental, and social benefits. Data for these variables can be gathered from scientific and grey literature, which allow a sufficient triangulation of information. Such a multi- approach methodology can provide the scientific community with data to ensure sufficient comparability of geothermal case studies. Both qualitative and quantitative primary and secondary data comprising demographics, social, economic, and institutional drivers of geothermal energy utilization were obtained in this way. The long-term expectation is to identify and classify factors in order to build the basis for further research and to help practitioners who are willing to replicate similar studies for different sites in Africa, in potential combination with other renewable energies plants.