Factcheck: How nuclear, gas, wind and solar power are affected during heatwaves - Carbon Brief

Nature & Climate Perspective

**Extreme heatwaves exacerbate ecological stress by forcing higher thermal water discharges into river systems while curtailing clean energy output. **

• Thermal discharge from nuclear and gas plant cooling during heatwaves escalates water temperatures, severely impacting freshwater biodiversity.
• Reduced efficiency in solar PV (thermal derating) and wind droughts during heatwaves shift load to carbon-intensive peaking assets, indirectly impacting regional carbon sequestration goals.
• Accelerating climate feedback loops necessitate resilient nature-inclusive energy planning to maintain long-term environmental and watershed stability.

Market & Policy Outlook

**Grid stress from climate extremes drives power price volatility and challenges corporate 24/7 clean energy matching under SBTi and Scope 3 frameworks. **

• Regulatory bodies are revising grid reliability mandates, forcing energy providers to integrate acute physical risk modeling to meet ICVCM-aligned permanence and stability expectations.
• Financial liquidity and power purchase agreement (PPA) pricing are experiencing structural shifts as extreme heat drives extreme price spikes and asset curtailments.
• Corporate buyers relying on I-RECs for decarbonization compliance face increased supply risk and volumetric mismatch during peak heatwave-driven grid events.