Enabling a low-carbon electricity system for Southern Africa

Southern Africa faces the dual challenge of providing affordable en-ergy to meet rapidly growing electricity demand while limiting car-bon emissions and socio-environmental impacts. We combined open-source geospatial, hydrological, and electricity grid -invest-ment models to develop cost-optimal low-carbon electricity path-ways for Southern Africa. If technology and fuel prices continue to follow current trends, wind and solar technologies can become the dominant sources of electricity in the region by 2040. Importantly, no new coal capacity is built in any scenario except when inter-regional transmission is constrained. Furthermore, despite the abundant hydropower potential in the region, nearly half of the planned hydropower capacity is not cost competitive, thus support-ing freshwater conservation efforts. An 80% clean energy target can halve annual greenhouse gas emissions by 2040, as compared with 2020, with only a modest 6% cost premium. Alternatively, retiring coal plants 20 years earlier could result in even greater emission re-ductions but could incur 12% higher annual costs.