Abstract
Can weather shocks undermine energy security in coal-dependent economies? Using matched high-resolution rainfall data at South Africa’s coal power plants and their contracted supplier mines—where coal accounts for about 80% of electricity generation—we estimate how upstream rainfall shocks propagate through the coal supply chain to affect plant performance and electricity reliability. We find that heavy rainfall at supplier mines reduces plant availability, primarily through unplanned outages. We also find evidence that upstream rainfall shocks increase the severity of load shedding. These results imply that rainfall-driven supply-chain disruptions can compound existing reliability constraints, and that ignoring these channels understates the social cost of coal dependence.