(Recasts with all-time peak milestone, ERCOT's statement)
July 18 (Reuters) - Texas homes and businesses set an all-time power consumption record on Wednesday as consumers crank up air conditioners to escape a brutal heat wave, according to the operator of most of the state's power grid.
The Electric Reliability Council of Texas (ERCOT) said demand reached 71,438 megawatts (MW) on Wednesday, topping the grid's August 2016 high of 71,110 MW. One megawatt can power about 1,000 U.S. homes.
To keep air conditioners humming, Texas utilities bought electricity from all sources, boosting power prices to their highest in almost seven years.
"Electric providers and ERCOT are working around the clock to ensure they have air conditioning to see them through this," ERCOT spokeswoman Theresa Gage said in an email.
ERCOT expects to keep hitting new demand records as summer 2018 continues, it said in a statement.
High temperatures in Houston were expected to reach 98-100 Fahrenheit (37-38 Celsius) every day from July 16-24, according to AccuWeather.
The normal high in Houston, the fourth-largest U.S. city, at this time of year is 94-95 Fahrenheit.
ERCOT had forecast usage would reach an all-time high of 72,492 MW on Wednesday, followed by 74,620 MW on Thursday, 75,225 MW on Friday, 72,200 MW on Saturday, 72,145 MW on Sunday, 75,896 MW on July 23 and 75,016 MW on July 24 before easing to 73,059 MW on July 25.
Power prices in the ERCOT North hub EL-PK-ERTN-SNL jumped to $351 per megawatt-hour on Tuesday, their highest since August 2011. That compares with an average of $37.15 so far this year and $26.67 for all of 2017.
Despite the retirement of three big coal plants in early 2018, ERCOT said it expects to have sufficient tools to manage tight reserves and maintain system reliability this summer.
Those tools include using a previously mothballed power plant, imports from other regions and consumer conservation.
ERCOT manages the flow of electricity to 24 million Texas customers, representing about 90 percent of the state's power load.
Reporting by Scott DiSavino and Eileen Soreng Editing by Bernadette Baum and Chris Reese