Beware of the Texas Dunkelflaute: ERCOT Warns "Slight Risk of Emergency Alert" in July

The German dunkelflaute is "cold without wind," while the Texas version is "hot without wind" but the result is the same: reduced wind power.

Grock art

On May 2, 2025, ERCOT released its Monthly Outlook for Resource Adequacy (MORA) report for July, saying that Texas can expect a repeat of the grid problems experienced in the last few summers:

There is a slight risk of ERCOT issuing an Energy Emergency Alert (EEA) in the later evening hours as solar generation ramps down. This report also accounts for the possibility of low wind production, which remains a risk for the July peak demand. Continued growth in battery energy storage capacity/availability helps offset this risk of low wind production. Under normal conditions, ERCOT anticipates there will be sufficient generation to meet customer demand. [emphasis added]

ERCOT is saying it may issue warnings that the State’s power grid may be strained starting at sunset in July and probably August. They did not say that the cause of this problem is that Texas depends on wind and solar to provide up to half or more of the State’s power on most days. So when the sun sets and the wind stops, the Texas grid is in trouble.

There are a couple of things to know about summers in Texas. Texas summers are hot—always have been and always will be. In most of Texas, daily summer temperatures are usually in the mid-90s to low 100s, especially in July and August. Another characteristic of Texas summers is that when the sun sets, the wind stops blowing, which I call the Texas dunkelflaute. It also strikes during the day in July and August, starting in the early afternoon.

Texas has added a lot of wind and solar power over the last 25 years and some natural gas, but no additional coal or nuclear capacity. Coal power has, in fact, declined, with some coal-generating plants being retired early. Texas has approximately 69,000 megawatts of natural gas power generation and roughly the same amount of wind and solar combined. During the day, when the sun is shining and the wind is blowing, wind and solar can generate 50% or more of the total power until sunset, when solar generation dependably goes to zero, and wind generation dependently drops, sometimes a lot. Texas now has a fair amount of battery storage, currently 11,372 MW, which comes to the rescue for a few hours but still leaves a big hole to fill.

Natural gas-generated power has always filled the gaps caused by failed wind and solar, but Texas is growing quickly and attracting many massive industrial, data centers, and cryptocurrency projects. ERCOT expects electricity demand to increase by 75% by 2030, which will require enormous investments in natural gas generation to handle much of the base load demand and fill in when the sun goes down and the Texas dunkelflaute hits.

To ensure that ERCOT has sufficient natural gas generation to handle the expected growth, Texas established the $5 billion Texas Energy Fund to guarantee low-interest loans to companies that build new natural gas generation, but according to ERCOT CEO Pablo Vegas, that program is only a band-aid for the problem, noting that low-interest loans help with upfront costs but don’t address long-term revenue uncertainty. This program will undoubtedly help attract new natural gas generation, but it will not be enough, soon enough. Nuclear power can potentially handle much of the State’s power needs eventually, but it is years away, so something else is required to keep the Texas grid growing and reliable.

My Take

Off-grid power generation and other market-based innovative solutions are the answer. Power grids and regional utilities are simply not capable of moving fast enough to provide the power needed by data centers, cryptocurrency miners, and large industrial facilities. Large data centers are already moving to provide their own power solutions, like Microsoft striking a deal with Constellation Energy to restart Unit 1 of the Three Mile Island nuclear facility.

Companies needing large amounts of power quickly are turning to innovative companies like RPower, Enchanted Rock, Scale Microgrid Solutions, RavenVolt, American Microgrid Solutions, Bloom Energy, VoltaGrid, and others to provide customized solutions featuring innovative power portfolios.

ERCOT was established to manage Texas’s deregulated electricity market, but it is no longer nimble enough to cope with the unprecedented growth in power demand. Market-based solutions, in conjunction with ERCOT, are the wave of the future.

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