Texas breaks power record as schools reopen

ERCOT Peak Power Demand surged to 65,715 MW amid a Texas heat wave, straining reserves as real-time prices spiked. Low summer wind output, high electricity usage, and tight grid capacity tested reliability and peak-load management.

Texas set a fourth all-time electric use record as many school districts and universities across the state resumed classes, boosting air conditioning demand and straining power supplies, according to initial data from the state grid operator.

Power use between 4 p.m. and 5 p.m. CDT was 65,715 megawatts, surpassing the 64,805-MW record set one week ago, said the Electric Reliability Council of Texas ERCOT.

Because of the economic slowdown, ERCOT did not expect peak-hour power consumption to reach 65,000 MW before the summer of 2011.

The record blew past the week-earlier record by 910 MW and the 2009 peak by 2,315 MW.

"The ERCOT region is continuing to experience high temperatures throughout the state which is causing high electricity usage," said Kent Saathoff, ERCOT's vice president of system planning and operations.

"We're very pleased that ERCOT system operators and the region's transmission and generation owners were able to manage today's record demand without any major issues," Saathoff said in a release.

Electricity from the state's many wind farms averaged 650 MW during the peak hour, just 1 percent of power demand, as wind speeds fall in the summer.

Real-time power prices briefly touched $2,200 per megawatt-hour as power use soared, but quickly dropped below $300 per MWh, according to the ERCOT website.

The grid operator issued an advisory that afternoon power reserves could be strained, elevating blackout risks across the region.

ERCOT has 66,228 MW of installed capacity and other available resources totaling 75,913 MW. Extra generation is needed as a cushion during periods of high demand to avoid rolling blackouts should a large power plant or transmission line fail.

High temperatures in the state's three largest cities — Houston, San Antonio and Dallas — were all forecast above 100 degrees Fahrenheit 38 degrees Celsius, according to Telvent DTN.

One megawatt can power about 500 average Texas homes under normal conditions, but only 200 homes during hot weather when air conditioners run for longer periods of time, the grid operator said.

Cold weather can also push electricity demand higher, as seen in past Texas winters.

Power use in Texas has exceeded ERCOT's summer peak forecast of 64,052 MW, which was just 1 percent above 2009's actual peak as the recession was expected to depress industrial power use.

Unlike many utilities in the Midwest and Southeast which watched power use slide since late 2008, the Texas power grid and the state's largest power delivery companies have reported slow, but continued, growth in electric use despite the recession.

Temperatures are forecast to slip a few degrees, reducing peak demand to less than 64,000 MW.

Power demand in Texas reached 63,594 MW on August 4, surpassing the 2009 peak of 63,400 MW. That record fell August 10 when peak-hour use rose to 63,830 MW and again on August 16, when the peak hit 64,805 MW, according to ERCOT.

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