High-temperature heat pumps for geothermal applications in Africa: thermodynamic, economic and environmental evaluation

Geothermal resources in Africa, from low- to high-enthalpy, remain underutilized despite their vast potential. The Rift Valley is rich in high-enthalpy resources for electricity generation, while the mainland offers abundant medium- and low-enthalpy sources suitable for diverse applications. This study explores the use of hightemperature heat pumps (HTHPs) with geothermal energy. The research develops a predictive model to assess the thermodynamic performance, economic viability, and environmental impact of large-scale HTHP deployment. The metamodels estimate key parameters such as installed capacity, heat output, and the Levelized Cost of Heat (LCOH). Life Cycle Assessment (LCA) quantifies environmental impact using a parametric Life Cycle Inventory (pLCI), linking HTHP construction impacts with thermodynamic performance. A key innovation of this study is its holistic approach, integrating technical, economic, and environmental evaluations to provide a comprehensive sustainability assessment. Environmental aspects focused exclusively on the Climate Change (CC) indicator. Unlike previous research, focused mainly on thermodynamics, this study includes cost analysis and environmental impact assessments using LCA methodologies. It also emphasizes real-world applications in Africa, where geothermal resources remain largely untapped. To bridge this gap, the model is applied to a Malawi case study, assessing hot-spring resources for sustainable cooking and vegetable drying, with direct socioeconomic benefits. Population density maps identify optimal user areas, showcasing HTHP feasibility in offgrid settings. Results highlight the potential of low-enthalpy geothermal energy for cost-effective, sustainable heating and industrial applications, reinforcing its role in Africa's energy transition. This study provides a replicable framework for advancing geothermal resource utilization and supporting sustainability goals within the LEAP-RE Project.