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Category — Electricity Outages

Texas Power Outages: A Preliminary Analysis (Cold snap brings failure–isolated ERCOT an issue)

[Editor note: Dr. Giberson is an instructor and research associate at the Center for Energy Commerce at Texas Tech University's Rawls College of Business. He blogs on energy economics and other topics at Knowledge Problem.]

On Wednesday morning, The Electric Reliability Council of Texas (ERCOT), operating the power grid for much of the state, called upon local distribution companies to cut power to blocks of consumers on a rotating basis.

The rolling outages produced hardship for millions, and even isolated instances of severe harm. Consumers and policymakers are dissecting what went wrong and what should be done about it. The following is a preliminary analysis based on public data and news reports. A subsequent post will present more details once more complete information becomes available.

In brief, extreme cold weather pushed power demand to very high winter levels. At the same time, fifty of the state’s power plants were offline due to the effects of the cold, and several others were undergoing planned maintenance. The combination of very high demand and reduced supply left the ERCOT grid perilously short of reserves. Rolling consumer outages were employed to protect the system from failing completely.

Some wondered whether wind power was at fault, but wind contributed about seven percent of ERCOT’s power during the emergency – about the same as this time last year.

No power system is immune to hazards. But policy decisions that increase the likelihood of hazards or multiply the resulting damages ought to be given careful reconsideration. In this case, the choice by Texas policymakers to keep ERCOT isolated from surrounding power systems prevented power companies within ERCOT from accessing excess power capacity elsewhere in the state and in neighboring states. Other policy issues also are raised by the emergency, but few solutions are likely to be as cost-effective and technically simple to implement as linking ERCOT to its neighbors.

Cold Snap

ERCOT reported that severe weather led to the loss of 50 generation units amounting to 7,000 MW of capacity on Wednesday morning. From news accounts it looks like a few large coal plants failed after water pipes burst. Some natural gas generators found insufficient fuel supplies due to heavy demand for natural gas. Other natural gas generators found their access to fuel curtailed by state rules that give priorities to other customer classes when supplies run short. In addition, a larger than usual amount of generation was off-line for scheduled maintenance – one estimate put this quantity at about 12,000 MW. [Read more →]

February 4, 2011   19 Comments