4AUG

MISO's second grid emergency in July

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10:53UTC

MISO declared its second maximum-generation emergency of the month on 15 July as a heat dome drove demand to a 122 GW peak, five days before FERC's grid-adequacy filing deadline.

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Key takeaway

MISO rationed power days before it had to certify to regulators that its supply was adequate.

MISO, the grid operator for 15 central US states, declared a maximum-generation emergency on 15 July, its second of the month, as a heat dome pushed demand to a 122 GW peak. A maximum-generation emergency calls on every available plant and asks large users to cut load, the last routine step before controlled blackouts.⁠¹ The declaration landed five days before the 20 July deadline the Federal Energy Regulatory Commission (FERC), the US regulator for interstate power, set for its six regional transmission organisations (RTOs) to file generation-adequacy reports.

FERC ordered those reports in place of a binding connection rule, and MISO's own figures show why the paperwork lags the weather. Data-centre load in its footprint has grown at a 43% compound annual growth rate (load CAGR, the yearly rate at which demand compounds) since 2020. The operator forecasts a 163 GW peak by 2035; it already touched 122 GW in a single July heat wave, so that forecast stacks another 41 GW on a grid that is rationing supply today.

The adequacy report describes supply on paper the same week the operator was cutting it in practice. That is the contradiction the FERC docket exists to interrogate, and MISO has now written it into the record twice in one month.

Deep Analysis

In plain English

MISO runs the electricity grid across 15 US states in the middle of the country. On 15 July, a heat wave pushed demand so high, 122 gigawatts at the peak, that MISO had to declare an emergency for the second time that month, meaning it may need to ask big power users to cut back to keep the lights on everywhere else. A big part of the extra demand is data centres, which have grown their electricity use by 43% a year since 2020 within MISO's territory. Five days later, the US grid regulator FERC (Federal Energy Regulatory Commission) was due a report from MISO and five other grid operators explaining how they plan to keep up.

Deep Analysis

Root Causes

MISO's 43% compound annual growth rate in data-centre load since 2020 has outpaced the multi-year lead times for new gas turbines and transmission build-out, so the grid operator is absorbing demand growth faster than physical generation capacity can be added.

The 20 July FERC adequacy-report deadline lands five days after this emergency, giving MISO live evidence of exactly the stress its report is meant to describe, rather than a hypothetical scenario regulators asked it to model.

What could happen next?

Risk
A second maximum-generation emergency in one month raises the chance MISO invokes involuntary load-shedding before the FERC-mandated tariff reforms, due around 17 August, take effect.
Meaning
MISO's 122 GW peak and 43% data-centre CAGR give the 20 July adequacy filing concrete numbers to reconcile against, rather than a hypothetical stress test.

Source Landscape

This story draws on neutral-leaning sources

Primary parallel: The Department of Energy's Section 202(c) emergency order let PJM curtail behind-the-meter data-centre generation during May's heat event; MISO's 15 July emergency is the same mechanism, a grid operator invoking crisis powers because demand outran planned supply, recurring for a second RTO within two months.

Counter-parallel: Ireland's EirGrid took the opposite legal route: rather than declare emergencies case by case, it wrote a standing curtailment rule capping instantaneous data-centre demand loss at 900 MW as a permanent grid-code condition. MISO and PJM still reach for emergency powers each time, with no equivalent standing rule.

Consensus view: MISO's own load forecasting, tracked by RTO Insider, has data-centre demand growing at a 43% compound annual rate since 2020 and driving the grid operator toward a 163 GW peak by 2035; the 15 July emergency, its second of the month, is read internally as an early data point on that trajectory.

Counter-view: FERC's Section 206 show-cause orders treat the strain as a tariff-design problem, not a physical shortfall: the six RTOs were told to justify or reform how large loads connect, on the theory that better cost allocation and curtailment rules, not new generation, can close the gap before 2027.

Key tension: Whether MISO's emergency reflects a genuine capacity deficit that only new generation fixes, or a queue-and-tariff design flaw that regulatory reform can resolve without adding a single megawatt.

Sources:RTO Insider

Mentions:MISO →FERC →EirGrid →Department of Energy →Section 202(c) →Ireland →Section 206 show-cause →PJM Interconnection →

First Reported In

Update #11 · Pipeline vetoed, campus keeps building

RTO Insider· 25 Jul 2026

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Causes and effects

This Event

MISO's second grid emergency in July

A grid operator rationing supply days before it must certify that supply is adequate exposes the gap federal regulators opened their docket to examine.

Led to

FERC sets a 20 July adequacy deadline

MISO's second July emergency landed five days before FERC's 20 July generation-adequacy deadline for the same six RTOs.

Occurred 19 Jul 2026

Read story →

FERC delays its grid rule to 2027

The emergency underscores the gap FERC's Section 206 show-cause orders were meant to address.

Occurred 18 Jun 2026

Read story →

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