Climate change is expected to significantly impact the electricity system of Southern Africa. In this study, the authors examine the potential impacts of climate change on electricity demand, hydropower energy availability, and thermal and solar power generation in the region’s electricity system from 2020-2045. System-level impacts are assessed by comparing cost-optimal energy generation mixes, costs, and carbon emissions of systems planned and operated assuming historical weather conditions with those under four future climate scenarios from the Coupled Model Intercomparison Project Phase 6 (CMIP 6).