EPRINC briefing
Grid Reliability and Resource Adequacy
31 publications
Briefing summary
During peak demand events, dispatchable generation carries the load: in the June 2025 heat dome, generation across five U.S. grids peaked at 401,000 MW (nearly 55% of national output), while Winter Storm Fern saw dispatchable sources supply 85–90% of ERCOT, MISO, and PJM demand.
Why have California and Texas experienced power disruptions?
ChartA Tale of Two States on Electricity PricesCalifornia and Texas illustrate divergent outcomes on electricity prices, with the two states following markedly different trajectories.Chart 2024-25ChartJune 2023 Texas Heat Wave and ERCOT GenerationDuring the major heat wave that began June 15, 2023, ERCOT intraday electricity demand peaked at roughly 70,000 to 80,000 megawatt hours, with the…Chart 2023-25EventEPRINC’s Max Pyziur Participates in Westchester County Association (WCA) Sustainable Business ConferenceOn Thursday July 14, 2022, the Westchester County Association (WCA) held their first Sustainable Business Conference. Focusing on the implementation…Mar 2023ChartERCOT: Freezin’ Down in Texas – Mid-Winter 2022-2023 Generation Mix, Shortfalls, and Refinery UtilizationDuring the winter of 2022-2023, two waves of extreme cold forced Texas' ERCOT grid into repeated generation shortfalls, with natural gas supplying…Chart 2023-06EventGGC/EPRINC Webinar “Power Disruptions in Texas and California: Energy Price Shocks in Europe”EPRINC has cohosted a webinar with the Global Gas Centre (GGC). The workshop was held on February 2, 2022 at 9:00 to 11:30 AM (Washington time) /…Feb 2022ChartCharts of the Week: ERCOT: Two Weeks in February “Freezin’ Down in Texas, All the Refineries are Down”During the mid-February 2021 cold event, ERCOT generation fell nearly 30 GW below system requirements, disrupting not only residential heating and…Chart 3EventEPRINC Hosts Virtual Workshop “Keeping the Lights on in California”EPRINC has hosted another virtual workshop, this one entitled “Keeping the Lights on in California: Some Simple Lessons for Sustaining…Sep 2020
Is the generation mix adequate to keep the lights on?
ChartPower Generation During Winter Storm Fern – The View From New EnglandDuring Winter Storm Fern, diesel-fired generation supplied an average of 31.3% of New England's electricity—peaking at 43.5%—despite costing roughly…Chart 2026-05ChartPower Generation During Winter Storm FernDuring Winter Storm Fern (January 22–26, 2026), dispatchable sources supplied 85% of average load and 90% at the 298 GW peak across the ERCOT, MISO,…Chart 2026-04ChartHeat Dome Regions (Northeast, Midwest and Texas) Power Generation (GW)During the late-June 2025 heat dome, power generation across the ERCOT, MISO, ISNE, NYISO, and PJM regions peaked at 401,000 MW between 5pm and 7pm,…Chart 2025-26EventSecond Electricity Series Workshop: Challenges in Meeting Surging U.S. Power DemandOn November 1, 2024, the Energy Policy Research hosted the second installment of the popular Electricity Series Workshops, entitled…Nov 2024ChartU.S. Mid-Summer Heat Wave Met by Record Natural Gas Power GenerationDuring the June 19–July 14, 2024 national heat wave, natural gas supplied between 38% and 52% of U.S. power requirements, and a sharp drop-off in…Chart 2024-30ChartEPA’s Power Plant Rule, Declining U.S. Electricity Generating Capacity, and Growing Power Demand Have Capacity Requirements Been Underestimated in the Face…EPA's newly finalized power plant rule would retire a substantial share of dispatchable coal and natural gas capacity even as demand pressures from…Chart 2024-17ChartNew England Winter Electricity Generation Mix: Some ConsiderationsAt peak winter demand, ISO New England generates approximately 12 thousand megawatts per hour, drawing an average of 46% from natural gas and 29%…Chart 2022-40ChartCalifornia Summer Hydroelectric Power Shortfall is ProjectedFollowing two years of drought, water levels at California's principal hydroelectric reservoirs are entering the summer at pre-peak levels well…Chart 2022-20ChartCan the California Electricity Grid Immediately Switch to an All EV Fleet?California's current electricity grid capacity would be insufficient to immediately support a full transition to an all-electric vehicle fleet…Chart 15
How do intermittent resources affect reliability?
ReportU.S. Nuclear Relicensing post-FukushimaDownload PDF Version of Report Nuclear Plants with Licenses Expiring Through 2016 On March 11, 2011 Japan was struck by a massive earthquake and…Mar 2011ChartThe April 2025 Iberian Peninsula Power Failure: An Overview with ConsiderationsOn April 28, 2025, the Iberian Peninsula experienced a widespread power failure that cut electricity across Spain and Portugal. This overview…Chart 2025-22ChartThe German Duck Curve Evolution of Germany’s Mid-Summer Electricity Generation Resource Mix Comparing 2017 and 2024Germany's mid-summer electricity mix now displays a pronounced "Duck Curve," as midday utility-scale solar output displaces other generation while…Chart 2024-47ChartThe Italian Duck Curve: Evolution of Italy’s August Electricity Generation Resource Mix — 2017-2023As utility-scale solar has grown in Italy, its August electricity generation mix now displays the "Duck Curve" first observed in California, with…Chart 2023-41ChartThe Spanish Duck Curve: Evolution of Spain’s August Electricity Generation Resource Mix — 2019-2023As utility-scale solar has expanded in Spain, midday solar output increasingly displaces other generation, producing a "Duck Curve" that requires…Chart 2023-35ChartImpact from Canadian Wildfire Smoke On Solar Generation in the Northeastern U.S.During the Canadian wildfire smoke event of June 5–8, 2023, solar generation in ISO New England fell to between 40% and 80% of its typical output,…Chart 2023-24ChartApril in Sacramento: More Solar Generation in California Requires More Natural Gas GenerationAs California's solar output grows, the state must call on natural gas generation to ramp up rapidly each afternoon as solar falls off. In April…Chart 2023-18ChartCalifornia Solar Generation During the 2022-2023 Pineapple ExpressDuring the 2022-2023 "Pineapple Express," heavy rain and cloud cover cut California's midday solar output to an average of 6.9 thousand megawatt…Chart 2023-04ChartUnited Kingdom’s Electricity Generation Mix: Some ConsiderationsExamination of hourly electricity generation in the United Kingdom during August 2022 indicates that, despite ongoing efforts to expand wind…Chart 2022-37ChartMid-Summer Electricity Generation: California & TexasDespite large installments of renewable energy capacity in California and Texas, both states continue to rely on substantial natural gas generation…Chart 2022-27ChartUK Electricity Capacity vs Electricity Generation Be Wary of the HeadwindsDespite the United Kingdom installing wind generation capacity that exceeds that of nuclear and coal, wind power capacity utilization remains low…Chart 14
What reforms would strengthen resource adequacy?
EventEnergy Policy Research Hosts Third Power Vision 2030 Workshop: “Fueling the AI Boom and Manufacturing Renaissance: US Power Sector Constraints & Solutions”On Thursday, January 16, 2025, Energy Policy Research hosted a workshop, Fueling the AI Boom and Manufacturing Renaissance: US Power Sector…Jan 2025ChartU.S. Utility-Scale Battery Storage DevelopmentsU.S. utility-scale battery storage capacity has grown from 1,570 MW in 2020 to 20,710 MW in 2024, an annualized rate of 90.6%, with California and…Chart 2024-44ChartEPA’s Proposed Grid Performance Standards and Their Impact on MISO’s Electricity GridMISO's electricity grid depends heavily on coal and natural gas generation, with hourly data from summer and winter 2023 showing natural gas ramping…Chart 2024-09