The relationship between the electric power system and environmental change is complex. Future changes to environmental risks such as heat waves and flooding can reduce grid reliability while increasing demand. Hydroclimatic variability may result in a weakening of hydropower as a firm, nonzero generation source over decadal time scales. And California has seen blackouts resulting from attempts to manage wildfire risks by power utilities. We investigate the impact of these mechanisms under deep climate uncertainty for today’s decisions about energy system infrastructure investments.