July 19 (Reuters) - Power demand by Texas homes and businesses has hit records and more highs are expected over the next week as consumers crank up air conditioners to escape a brutal heat wave, according to the operator of much of the state's power grid.
To keep those air conditioners humming, Texas utilities bought electricity from all sources, keeping power prices near seven-year highs hit earlier in the week.
The Electric Reliability Council of Texas (ERCOT) said demand reached 72,192 megawatts on Wednesday, topping the prior all-time high of 71,110 in August 2016. One megawatt can power about 1,000 U.S. homes.
Wednesday's peak was shy of the grid's forecast high of 72,756 MW for this summer, but that is not expected to last long.
ERCOT predicted peak daily demand would break Wednesday's high over the next several days, including Saturday and Sunday, when usage usually falls as businesses close for the weekend.
High temperatures in Houston were expected to reach 98-101 degrees Fahrenheit (37-39 Celsius) every day from July 16-23, according to AccuWeather. The 100-101 degree highs forecast for Saturday-Monday would break the record of 99 degrees set in 2000 for Saturday and Monday and 2016 for Sunday.
The normal high in Houston, the fourth-largest U.S. city, at this time of year is 94-95 degrees F.
ERCOT forecast usage would set a new all-time high of 73,656 MW on Thursday, followed by 74,698 MW on Friday, 72,681 MW on Saturday, 72,337 MW on Sunday and 76,204 MW on Monday before easing to 73,282 MW on Tuesday and 71,926 MW on July 25.
Power prices at the ERCOT North hub EL-PK-ERTN-SNL slipped to $300 per megawatt hour on Wednesday from $351 on Tuesday, which was their highest since August 2011. That compares with an average of $39.44 so far this year and $26.67 for all of 2017.
Despite the retirement of three big coal plants in early 2018, ERCOT has said it expects to have sufficient operational tools to manage tight reserves and maintain system reliability this summer.
Those tools include using a previously mothballed power plant, imports from other regions, consumer conservation and demand response efforts, which compensate consumers for cutting electric usage.
ERCOT manages the grid for 24 million Texas customers, representing about 90 percent of the state's electric load.
The biggest power utilities in Texas include units of Sempra Energy, CenterPoint Energy Inc, American Electric Power Co Inc, Entergy Corp and Xcel Energy Inc.
Reporting by Scott DiSavino; Editing by Bernadette Baum