Increasing the deployment of solar PV in the commercial sector in South Africa: Buildings as assets for energy transition

South African electricity system is undergoing an energy transition towards increased use of renewable energy. The share of coal-generated power was 83 % in 2022 versus 94 % a decade ago, and renewables generated 8 % of electricity. At a large utility-scale, the integrated resource planning (IRP) process is a policy vehicle used to increase renewable energy penetration within the grid. However, at the distributed and small-scale level, the process of renewable energy uptake is heterogeneous, complex, and user-centric. It relies on customer preferences, cost, enabling municipal regulations and tariffs. This dynamic adoption makes planning for distributed energy systems very complex as energy planning tools are designed for centralised planning. To overcome this planning challenge, this paper adopts a three-step modelling process to estimate rooftop solar PV adoption for commercial buildings. This modelling process combines optimisation, market research and simulation modelling approaches using the availability of commercial building rooftops, rooftop suitability properties and solar PV resources as constraints. With excellent solar PV resource potential in the country and at high rooftop suitability levels of 80 %, up to 12 GW of solar PV rooftops can be installed on commercial buildings. Therefore, commercial buildings can serve as strategic assets for decarbonisation and increase the security of the power supply.