Low wind speeds may limit Texas' power system maintenance window: Maguire

An enduring spell of low wind speeds across Texas has forced the state's power firms to increase generation from fossil fuels to record highs so far in 2025, potentially leading power firms to shorten or delay planned maintenance breaks this spring.

The Electric Reliability Council of Texas (ERCOT) power system, one of the largest in the United States, covers around 75% of Texas' land area, including the state's energy-intensive industrial corridors on the south coast.

Typically, ERCOT power firms schedule plant maintenance in March and April when overall power demand tends to dip between the winter heating season and the energy-intensive summer when demand for cooling systems peaks.

This year, ERCOT estimated that around 17% of the system's thermal power generation capacity of around 85,000 megawatts was scheduled for maintenance in March, which would require certain plants to throttle back or temporarily halt output.

However, below-normal wind power production has meant ERCOT system planners have had to keep generation from fossil fuels plants at near record levels, which is eating into the time window for maintenance crews to get to work.

WIND WOES

Wind farms typically account for more than a third of ERCOT's total power generation during opening months of the year, as high winter wind speeds help boost clean power flows.

However, ERCOT wind power generation during February was 18% below February 2024 levels due to low wind speeds, data from LSEG shows.

This in turn pushed wind's power share to just 26% of the ERCOT total last month, compared with a 36% share in February 2024.

To make up for the wind shortfall last month, power firms boosted generation from coal plants by 49% from the same month in 2024 to the highest February total in three years.

ERCOT firms also boosted output from natural gas-fired plants by 33% from February 2024, LSEG data shows, and have had to sustain high fossil fuel-fired production levels so far in March as wind generation levels remain stunted.

FORECAST

After the sub-par wind generation total for February, power traders had anticipated a rebound in wind output during March and April, which have typically been the highest wind generation months in the ERCOT system.

However, while wind production picked up at the start of March, the forecast for the coming week or so indicates a fresh drop in output is likely from current levels.

Longer-term forecasts for wind generation are less reliable than shorter-term forecasts, and are not widely relied upon.

The spotty nature of wind output this year has in turn meant that fossil fuel power plants have had to increase their overall share of ERCOT generation, which in February 2025 was 57% compared to 54% in February 2024 and February 2023.

MAINTENANCE WINDOW

If wind power levels remain below average this month, firms may struggle to complete the required maintenance on coal and gas-fired plants before power demand rises again when summer kicks in and temperatures and humidity levels rise.

While new power plants may only need a few days for maintenance work to be completed, older and more complex systems can require weeks of work to properly prepare them for the peak summer demand season.

And with the average age of Texas coal plants around 50 years and gas plants around 30 years, according to ERCOT, both sets of fossil plants in the ERCOT system can need regular and extensive maintenance and upgrades.

Currently, ERCOT system demand levels are approaching their lows for the year, and average temperatures for Houston through mid-March are forecast to hold around 75 to 80 degrees Fahrenheit (24 to 26 Celsius), which is normal and should not lead to sustained demand for power-hungry air conditioners.

However, temperatures tend to climb from May, which means there is less than 10 weeks to take care of the state's roughly 20 coal-fired, 17 oil-fired and 162 natural gas-fired power plants before they may be needed to crank output again.

At normal wind generation levels, there would be plenty of scope to dial back output at multiple thermal power plants at this time of year, and accommodate the maintenance work.

But this year's weak winds mean that ERCOT's fossil power network may need to maintain output levels for longer than normal, and leave maintenance crews with a shorter than normal window to prime the fleet for the summer rush.

The opinions expressed here are those of the author, a market analyst for Reuters.