Fig. 3: Climate impacts on generation capacity and transmission capacity built, generation, and total costs.

a Baseline Scenario and cumulative change in Western Interconnection generation capacity built in 2030–2050 for climate scenarios. Black points indicate the total net change in generating capacity across all energy sources under each climate scenario relative to the Baseline Scenario. Each climate scenario is named after the Global Circulation Model (GCM) from which the climate projection originates. b Baseline Scenario and cumulative change in transmission capacity built in 2030–2050 for climate scenarios. The light pink bar indicates existing transmission capacity in 2030, and the red bars indicate new transmission built between 2030 and 2050. c Baseline Scenario and change in 2050 generation for climate scenarios relative to Baseline Scenario. Black points indicate the total net change in generation under the climate scenarios relative to the Baseline Scenario. The energy storage bars indicate discharge of battery storage (equivalent to generation). d Baseline Scenario and change in total system cost in 2030–2050 for climate scenarios. The Baseline and change in costs are in Net Present Value (NPV) terms using 2018 as the base year and a discount rate of 5%. The climate scenarios in plots (b–d) are sorted from lowest to highest change in cumulative generating capacity built in 2030−2050, based on the scenario ranking shown in plot (a). Source data are provided as a Source Data file.