HOUSTON (Reuters) - ERCOT, the power grid operator for most of Texas, again urged customers to conserve power on Thursday morning to avoid a return of rolling blackouts as demand tops the winter record, stressing generation supplies.
The grid operator said demand Thursday morning reached 57,282 megawatts at 8 a.m. CDT (1400 GMT), surpassing last week’s winter record by more than 900 MW.
Last week, when the grid operator imposed rolling blackouts with very little warning to avoid a system-wide collapse, usage reached what was then the winter record of 56,334 MW.
ERCOT said it had more reserves as a precaution, and was not anticipating any state-wide rolling outages Thursday.
But the grid operator warned a significant number of generation outages like last week could change that.
A week ago, more than 50 generating units capable of producing 7,000 MW of power shut due to extreme cold, forcing ERCOT to impose rolling blackouts that lasted several hours.
ERCOT oversees the dispatch of about 550 generating units and operation of 40,000 miles of high-voltage transmission lines.
Wednesday night, ERCOT said about 2,700 MW of generating capacity remained unavailable for service due to unplanned or forced outages.
Even though ERCOT did not expect a return of the state-wide rolling blackouts, the grid operator did warn of a higher risk of rolling blackouts in the Rio Grande Valley area Thursday morning due to transmission line limitations.
American Electric Power Co Inc’s AEP Texas utility, which operates the power system in the Rio Grande Valley, also urged its customers to conserve power, warning of possible rolling blackouts.
Electricity traders did not seem too worried about problems in Texas as prices for the rest of the day were only in the $60s per megawatt hour and prices for Friday were in the $40s.
On Wednesday, prices for the balance of the day were in the $50s and most next-day prices were in the $80s and $90s.
Last week, when the blackouts were rolling, real-time power prices reached the $3,000 price cap and next-day prices hit $500.
The U.S. National Weather Service issued a “hard freeze warning” for parts of Texas, including Houston, through Friday, but warmer daytime temperatures should reduce overall power demand.
Temperatures were expected to climb above freezing in the three biggest cities in Texas, which are among the top 10 cities in the U.S., according to AccuWeather.com:
Reporting by Scott DiSavino and Eileen O'Grady; Editing by David Gregorio