Climate change may amplify the frequency and severity of supply–demand mismatches in future power systems with high shares of wind and solar energy1,2. Here we use a dispatch optimization model to assess potential increases in hourly costs associated with the climate-intensified gaps under fixed, high penetrations of wind and solar energy generation. We further explore various strategies to enhance system resilience in the face of future climate change. We find that extreme periods—defined as hours in the upper decile of hourly costs (that is, the most costly 10% of hours)—are likely to become more costly in the future in most countries, mainly because of the increased need for investments in flexible energy capacity. For example, under the Shared Socioeconomic Pathway SSP1–2.6 scenario, 47 countries that together account for approximately 43.5% of global future electricity generation are projected to experience more than a 5% increase in average hourly costs during extreme periods, with the largest reaching up to 23.7%. The risk of rising costs could be substantially mitigated through tailored, country-specific strategies involving the coordinated implementation of multiple measures to address supply–demand imbalances and enhance system flexibility. Our findings provide important insights for building future climate-resilient power systems while reducing system costs.
