South Africa's energy mix and sustainability outlook for 2030: A system dynamics approach

South Africa's Integrated Resource Plan (IRP) of 2019 targets a 39% share of renewables in the national energy mix by 2030, aiming to deliver 6.51 exajoules (EJ) of energy, up from 5.74 EJ in 2022. To evaluate the feasibility of this target, this study employs a system dynamics approach to analyze the interactions among six key factors: energy development, economic activity, technological progress, environmental outcomes (measured as the renewable share), social impacts (primarily employment), and policy effectiveness. The model employs stock-and-flow structures and causal loop diagrams to represent reinforcing feedback loops, such as those linking renewable energy expansion to job creation and enhanced policy support, alongside balancing feedback loops arising from bureaucratic and regulatory delays. Two scenarios were assessed: one reflecting current policy effectiveness (P = 0.68) and the other assuming enhanced policy implementation (P = 0.81). Model projections indicate a substantial transition in South Africa's energy mix by 2030. The share of coal is projected to decline from 72.7% in 2022 to 42.95%, while the contribution of renewables is expected to increase to 39.07%. This shift is supported by approximately 55.4 GW of renewable installed capacity, projected to generate around 2.52 EJ of annual energy output. However, given an aggregate capacity factor of only 28%–30%—with wind at 36%–38% and solar PV at 25%–26%—only 0.7–0.8 EJ of this output is expected to be reliably available each year. Overall, the total installed generation capacity is projected to reach approximately 104 GW, yielding an estimated 6.45 EJ of annual energy output. This remains 0.06 EJ below the projected demand. Even with the inclusion of 0.645 EJ of storage capacity, roughly 2.8% of energy demand is anticipated to remain unmet, highlighting persistent concerns about system reliability. In addition, the Renewable Energy Independent Power Producer Procurement Programme has generated substantial cumulative job-years since its inception in 2011. Under current trends, the model forecasts ∼50 000–60 000 additional job-years and ∼250 billion South African Rand (ZAR) in economic output by 2030. The model also shows that each annual 1% increase in the renewable share is associated with the creation of approximately 3500–4000 jobs and a projected 15% reduction in CO2 emissions. Despite measurable progress, challenges such as the variability of renewable generation and slow policy implementation continue to constrain adoption. Addressing these gaps and achieving the IRP 2019 targets will require more effective policies, streamlined regulatory processes, and targeted investment in both storage and dependable baseload generation.