Texas braces for another record electric-use day

HOUSTON (Reuters) - The Texas grid operator braced for another record-breaking day for power consumption on Thursday as hot, humid weather is expected to strain the state's power supply to keep air conditioners running.

Texas set an all-time electric use record on Wednesday, according to initial data from the state grid operator.

However, conservation efforts may curbing demand. At 11 a.m. CDT (1600 GMT), actual power use was running about 1,200 megawatts below the same hour on Wednesday, according to the grid operator.

High temperatures in Dallas and San Antonio were forecast to reach 102 Fahrenheit (38 Celsius) while Houston and much of south Texas will broil in the high 90s F, according to AccuWeather.com.

The potential record-breaking demand could occur even though temperatures are far from the hottest recorded. The record in Dallas for July 9 is 106 F (41 Celsius).

The summer record was set early this year. Normally, the state sees power use peak in August unless hurricanes or afternoon storms reduce demand. The previous July monthly peak-hour record had been 60,661 MW set in 2006 while the all-time record was 62,339 MW set in August of that year.

The Electric Reliability Council of Texas (ERCOT) had trimmed its summer consumption forecast this year due to the economic slowdown. ERCOT said Texas demand would reach 63,491 megawatts, down 4 percent from 2008's forecast but 2 percent above the 2008 actual demand peak, which was reduced by cool weather.

CONSERVATION URGED

Peak-hour power use Thursday and Friday is forecast to exceed 63,000 MW, according to the ERCOT website, potentially breaking Wednesday's record.

The Electric Reliability Council of Texas (ERCOT) said power use at the hour ending at 5 p.m. CDT (2200 GMT) Wednesday, was 62,786 megawatts, beating a 2006 summer record by 447 MW.

No power disruptions occurred and no unusual emergency action was taken by the grid operator Wednesday but ERCOT extended a conservation advisory Thursday by asking residents to curb electric use from 3 p.m. to 7 p.m. CDT due to expected high cooling demand and tight supplies.

The grid operator said about 4,500 MW of generation was shut Thursday for unscheduled maintenance, a high number for the summer, but little changed from the previous day.

Next-day power prices for Friday delivery were trading around $150 per megawatt-hour, sources said, slightly under prices seen for Thursday delivery.

Luminant was working to restart the 575-MW Big Brown 1 coal-fired unit in central Texas on Thursday after a forced shutdown on Tuesday, the company told regulators in a report.

Luminant's new 581-MW Sandow 5 coal unit, which the grid operator expected to be in service this summer, is not yet producing power, a Luminant spokeswoman said Thursday.

One megawatt can serve about 500 average homes under normal conditions in Texas or 200 homes during hot weather.

(Reporting by Eileen O'Grady; Editing by Lisa Shumaker)