This is the fourth post in my series on the electric system impacts of the late-June/early-July 2026 heat wave. The first two posts (here and here) covered the New York Independent System Operator (NYISO) system, and the third covered data that Rich Ellenbogen shared from his home and factory on the Con Edison system. This post looks outside New York, at how nearby regional transmission operators PJM, ISO New England, Midcontinent Independent System Operator (MISO), Ontario’s Independent Electricity System Operator (IESO), and Hydro-Québec handled the same event, with the focus on whether wind and solar were available when the grid needed them most.
I am convinced that implementation of the Climate Leadership & Community Protection Act (Climate Act) net-zero mandates will do more harm than good if the future electric system relies only on wind, solar, and energy storage because of reliability and affordability risks. The opinions expressed in this article do not reflect the position of any of my previous employers or any other organization I have been associated with, these comments are mine alone. I acknowledge the use of Perplexity AI to research and organize the material summarized in this article.
Overview
My first post in this series found that the heat dome that stressed New York’s grid was, for most of the event, centered close enough to New York to leave a decent pressure gradient — and therefore decent wind — over the state on most days, with June 29 the exception. A rapid-attribution analysis found that the anticyclone driving the heat wave was centered over the northeastern United States and southeastern Canada and stayed nearly stationary for about a week, with light-to-moderate winds across eastern North America. Note, however that I completely disagree with the analysis claim that human driven climate change had a greater impact than natural variability. The weather pattern affected operators sitting under or immediately downwind of the ridge core — PJM, MISO, and Ontario’s IESO — had significant wind shortfalls, while ISO-NE, helped by offshore wind on the maritime margin, did not. U.S. weekly electricity output for the week of June 28 – July 4, 2026 reached 100,996 GWh — the first week ever above 100,000 GWh, up 7.73% year over year. This was a continental event, and the country’s largest grid operator came closer to real trouble than New York did.
PJM: The Most Acute Stress in the Country
PJM Interconnection, serving 13 mid-Atlantic and Midwest states plus D.C., ran through the entire emergency ladder, making the New York Independent System Operator (NYISO) Energy Watch look mild. PJM issued Hot Weather Alerts starting June 29, escalated to a NERC EEA1 on July 1, then to EEA2 with a “Deploy All Resources” action at 5:36 p.m. on July 2, along with a Low Voltage Alert and Heavy Load Voltage Schedule Warning (PJM Operating Committee presentation; Sunairio). The U.S. Department of Energy issued two emergency orders under Federal Power Act section 202(c) to PJM on June 30, and a third effective July 2 that ran through July 6.
PJM served an estimated all-time peak of 168,158 MW between 5 and 6 p.m. on July 2, breaking the prior record of 165,563 MW set in August 2006. Forced generation outages ran between 18,100 and 19,400 MW on July 2–4, versus an average of only 12,800 MW on the top-10 summer peak days of the prior three years, and operating reserves collapsed from 10,996 MW on July 1 to just 5,091 MW on July 2 (PJM Inside Lines; mgrid). PJM’s Senior Manager of Dispatch put it bluntly: PJM “used every single generator available on July 2,” calling it the highest peak ever served, and adding that “our capacity position continues to be an area of concern” (PJM Inside Lines).
Wind was scarce almost exactly the way New York’s wind was scarce on June 29, except PJM never got the reprieve New York got on the other days. Independent fuel-mix analysis found that nuclear, coal, and gas together supplied 88% of PJM generation during the heat wave, while solar and wind combined were flat at just 7.5 GW, unchanged from the prior week; coal output rose 69% and gas rose 26% to cover the gap (EPRINC). The Department of Energy stated that during the 5 p.m. peak hours of July 2 and 3, 82% of available wind power failed to produce, and when the sun goes down solar goes offline (DOE, via Shore News Network) — a political characterization rather than a PJM operational metric, but consistent with the underlying meteorology and the independent fuel-mix data. Solar did perform well during daylight, reaching over 11,000 MW at the record hour (Grid Strategies), but when the sun goes down it does not help with the post-sunset net-load peak, exactly the deliverability problem PJM itself flagged.
PJM leaned hard on demand response, deploying an average of 6,113 MW on July 2 and 5,037 MW on July 3 (PJM Operating Committee presentation — essentially its entire contracted demand-response fleet and then some (Grid Flexibility case study). Imports offered little cushion: PJM was actually a small net importer at the record hour, drawing roughly 900 MW total from MISO, NYISO, LG&E, and TVA — a rounding error against a 168 GW peak (Grid Strategies). West Hub on-peak day-ahead prices averaged $479.27/MWh on July 2, the highest for any July or summer day on record (S&P Global). PJM avoided firm load shed, but a record peak, near-record outages, collapsing reserves, and near-total demand-response deployment is about as close to the edge as an operator can get without a blackout.
ISO New England: Tight, But Wind Actually Helped
ISO-NE issued a precautionary Abnormal Conditions Alert effective 5 p.m. on July 1, explicitly stating “this is not a system emergency,” and lifted it at 10 p.m. on July 3 (ISO-NE event record; ISO-NE newswire). ISO-NE warned that “there is little surplus generating capacity available to deal with unanticipated events,” and flagged that heat “affecting systems to the west and the north, including New York and Quebec” was “increasing uncertainty regarding energy imports to New England” (ISO-NE newswire) — a direct acknowledgment that its reliability depended on neighbors who were themselves under stress.
The July 2 peak of 25,351 MW was ISO-NE’s 2026 high, below the all-time summer record of 28,130 MW from August 2006, though behind-the-meter solar brought it within roughly 500 MW of that record (Central Maine / Portland Press Herald; Grid Status). Unlike PJM and MISO, ISO-NE’s wind performed well throughout: roughly 57 GWh generated, a 78% increase over 2025, never below 400 MW, and strongest during the afternoon and evening peak, driven largely by offshore wind (Grid Status). American Clean Power says offshore wind alone met almost 12% of total demand on July 2 (American Clean Power). That is geography and luck, not evidence that wind can be counted on generally because if the center of the heat dome was more to the northeast the wind would have failed.
MISO: High Load, Weak Wind, No Emergency
MISO declared no maximum generation emergency during this window; its first Energy Emergency Alerts of the summer came two weeks later, on July 15 (Grid Status), despite peaking at roughly 121–125 GW on June 30, within about 2 GW of its all-time record of 127 GW set in 2011 (Politico).
MISO’s wind was the second clear shortfall of the event. Grid Status reported that MISO wind was weak across the entire footprint and “particularly underperformed the forecast during the evening peak period” (Grid Status), which directly conflicts with a claim from American Clean Power, an industry trade group, that MISO wind delivered roughly five times more electricity than forecast at the peak hour (American Clean Power). The operational synopsis — wind underperforming forecast at the evening peak, when it matters most — deserves more weight than a trade-group framing.
MISO’s solar reached a peak of 18.6 GW on July 1, coal hit its highest output of 2026 to date, and batteries discharged only about 1 GW at peak, which Grid Status called “still well below the level required to cover the net load peak” MISO got through the event without an emergency and was even a net exporter, but did so on the back of coal and gas, not wind (Grid Strategies).
Ontario and Québec: The Same Ridge, the Same Wind Drought
Canada’s two largest eastern grid operators sat under the same stalled ridge as PJM and MISO, and Ontario’s experience is arguably the most direct confirmation of this series’ thesis. Ontario’s Independent Electricity System Operator (IESO) set its highest demand day of 2026 to that point on July 2, peaking at 24,734 MW during hour ending 18:00 (IESO Power Data) and July 1 and June 30 both landing in the 23,500–23,900 MW range (load-record compilation); Ontario natural-gas generation was tracking 7% above July 2025 levels for the broader event (Grid Status). Wind was nearly absent. A watchdog site tracking IESO’s public power-data feed reported that with Ontario demand above 18,000 MW, wind power was providing barely 300 MW province-wide, noting flatly that “wind is absent during most heat waves” (Ottawa Wind Concerns). A separate Ontario energy-policy blog found that industrial wind turbines generated just 9.9% of rated capacity on July 4 and only 7.2% on July 5 during the tail of the same ridge, while gas generation covered the gap — in the author’s words, gas “saved us from blackouts” (Parker Gallant Energy Perspectives). That is the same wind drought PJM and MISO experienced, documented independently on the other side of the border.
Storms tied to the heat wave also knocked out power to as many as 168,000 Hydro One customers in Ontario on July 1–2 (CityNews Montreal), and to as many as 140,000 Hydro-Québec customers on the night of July 2, with 30,000 to 50,000 still without electricity as of July 3 (CTV News; The Montreal Greek Times).
Québec matters here too: New York and New England leaned on Hydro-Québec’s hydro-based system as a backstop, and that backstop had complications of its own. NYISO drew a daily average of about 1,400 MW per hour from Hydro-Québec and 800 MW per hour from Ontario’s IESO on July 3, together covering 9% of NYISO’s demand (U.S. Energy Information Administration). But the new 1,250 MW Champlain Hudson Power Express tie line sat out entirely from July 1 through midday July 2 because of an outage on the Québec side of the border, reached full output only by mid-afternoon July 2, and then tripped into another unplanned outage on July 4 — right as the heat wave was peaking. Net flows from Hydro-Québec into NYISO ended up down nearly 14 GWh compared with the June 2025 heat event, despite the new line (Grid Status). Even that hydro-heavy backstop could not fully deliver during the worst days of this event.
Comparing the Regions
- PJM — all-time record peak (168,158 MW); NERC EEA2 and two DOE orders; wind and solar flat at 7.5 GW; reserves fell by more than half in a day.
- ISO-NE — 2026 peak (25,351 MW), below the all-time record; precautionary alert only; wind up 78% year over year, never below 400 MW.
- MISO — within 2 GW of its all-time record (121–125 GW); no emergency; wind underperformed forecast at the evening peak; solar and coal covered the gap.
- IESO (Ontario) — 2026 high (24,734 MW); wind fell to a few hundred MW against 18,000+ MW of demand; gas covered the gap; storms cut power to 168,000 customers.
- Hydro-Québec — storms cut power to 140,000 customers; the CHPE tie to NYISO sat idle for a day and a half, then tripped again July 4; net exports to NYISO fell from previous episodes.
Conclusion
The pattern across this heat wave was not that renewables failed everywhere — it is that wind availability tracked the weather system’s geography almost perfectly. New York, PJM, MISO, and Ontario all sat inside or near the ridge’s weak-gradient zone and paid for it in scarce wind; offshore New England did not.
That is exactly the concern I raised in my first post in this series: the weather conditions that produce the highest electricity demand — a stalled summer ridge trapping hot, humid air over a broad region — are frequently the same conditions that suppress wind output over that same region, and that region can be enormous. PJM’s dispatch manager said the capacity position “continues to be an area of concern” after setting an all-time peak with almost nothing from wind and solar combined. Ontario’s independent observers watched the same story play out with their own wind fleet, entirely independent of anything happening in the U.S. grids. New York avoided the worst of it this time only because the ridge sat somewhat south of the state for most of the week, and even then, the Canadian hydropower it counts on as a backstop had its own outages and tie-line failures at the worst possible moments. There is no meteorological law guaranteeing any of these systems will be so fortunate next time. A future grid that depends more heavily on wind, solar, and short-duration storage needs to be planned for exactly this kind of correlated, region-wide shortfall. If all New York neighbors transition to similar weather-dependent electric systems then the New York system cannot count on any imported power.
Pragmatic Environmentalist of New York 