What’s behind the blackouts? Power plants not designed for cold weather

Today’s rolling blackouts in Texas has prompted our readers to share their conspiracy theories on what’s really behind the emergency:

“We either lost a lot more than 7,000 megawatts or there’s market manipulation ala Enron style,” Pat wrote in on the FuelFix comments.

“There sould NOT be any electrical shortages here right now, unless we are selling our Texas Power off to other states!!!” writes Trey (somewhat breathlessly).

Others speculate that natural gas for power plants has been curtailed because of demand for the gas elsewhere.

At the heart of the problem, however, is simply that many Texas power plants broke down because they’re not designed to handle lengthy cold spells.

Allan Koenig, director of communications for Dallas-based Luminant, the state’s largest power plant operator, said wet weather followed by more than a day of very cold weather can lead to exposed pipes and other equipment at Texas power plants freezing. Unlike states like Illinois or New York where lengthy cold weather is expected, Texas power plants don’t have all of their equipment insulated or protected in the same way.

Indeed Lt. Gov. David Dewhurst told the Associated Press that water pipes at two plants, Luminant’s Oak Grove coal-fired plant in Robertson County and Austin Energy’s natural gas fired Sand Hill plant, forced the operators to shut down.

This problem isn’t specific to natural gas or coal fired plants, but natural gas plants may be subject to another cold weather peril: during extreme cold the small amounts of water that are in pipeline natural gas may separate and freeze in valves.

It appears most of the power plant outages were in the northern part of the state where the cold weather hit  more than day before it arrived in the Houston area.

NRG Energy, the state’s second-largest power plant operator with most of its units near Houston, reported all of its major plants remained online, and at at one point this morning it was handling up to 15.5 percent of the state’s total load.

Koenig said Luminant, which has most of its plants in North Texas, had a larger number of plants offline due to the cold.