Mark Olsen, manager of reliability assessments at the North American Electric Reliability Corporation (NERC), presented a webinar (Clean Energy States Alliance, April 22, 2025) summarizing findings from NERC's 2024 Long‑Term Reliability Assessment and related reliability leadership work. The session was a technical briefing-style presentation that emphasized probabilistic methods (loss-of-load hours and expected unserved energy) and a 10-year planning horizon. Olsen showed NERC's risk map (high/elevated/normal categories) and explained that more than half of the continent faces growing energy risk driven primarily by a step-change in demand growth, continued retirements of thermal plants, and uncertainty/timing in bringing new resources online.

Olsen walked through specific metrics and implications: the interconnection queue grew by about 44 GW (12%) and is dominated by solar and battery projects, but actual adds lagged projections except for batteries. NERC accounted for roughly 78 GW of thermal retirements in its baseline and flagged another ~37 GW announced but not yet removed from planning, concentrating risk in market areas such as PJM and MISO. Winter reliability is emerging as a particular concern—winter peak growth is outpacing summer growth in many regions, winter shortfall events can last much longer (example winter events modeled up to ~12 hours), and short-duration batteries (2–4 hours) have limited ability to solve extended winter energy deficits. Transmission planning activity has increased (≈28,000 circuit miles in development vs a historical average near 18,000), but construction bottlenecks, permitting and siting issues (affecting ≈1,200 miles) slow realized delivery benefits. Olsen highlighted the interregional transfer capability study showing transmission can reduce some shortfalls but will not eliminate the need for additional resources. His recommendations for state and federal policymakers: pursue an all-of-the-above resource strategy, carefully manage generator deactivations, improve permitting and siting coordination, mature probabilistic and multi-weather-year modeling, account for grid-enhancing technologies, and plan for longer-duration storage and firm resources to cover growing winter and multi-day energy needs.