By Scott DiSavino and Arathy Somasekhar
(Reuters) -Two U.S. electric grids issued alerts warning of the potential for power shortages on Thursday due to a brutal heat wave blanketing Texas and U.S. Central states.
The Electric Reliability Council of Texas (ERCOT), which operates the grid for more than 26 million customers, called for voluntary conservation and asked state regulators to be allowed to exceed air quality standards.
ERCOT faces "a high potential to enter emergency operations this evening" due to low wind generation and high power demand, the grid operator said. Its website showed the potential for available capacity to fall short of demand by 95 megawatts at 7:55 p.m. local time.
Texas residents have worried about extreme weather since a deadly winter storm in February 2021 left millions without power, water and heat for days as ERCOT fought to prevent a grid collapse.
AccuWeather forecast temperatures in Houston, the biggest city in Texas, would reach 107 degrees Fahrenheit (41.7 degrees Celsius) on Thursday. That compares with a normal high of 94 F (34 C) for this time of year.
ERCOT forecast demand would reach 84,928 megawatts (MW) on Thursday, just shy of its 85,435 MW record set Aug. 10.
Unlike other U.S. grids, which can import thousands of megawatts from neighboring regions, ERCOT is heavily dependent on its own generation since its transmission system has few interconnections with neighboring systems.
Next-day prices at the ERCOT North Hub, which includes Dallas, soared to $925 per megawatt hour for Thursday from $255 for Wednesday. That compares with an average of $75 so far this year, $78 in 2022 and a five-year (2018-2022) average of $66.
MISO LOOKING FOR POWER
The Midcontinent Independent System Operator (MISO), which oversees the grid serving 45 million people in 15 states from Minnesota to Louisiana, also projected it might not have enough resources to meet forecast demand on Thursday.
"Due to the extreme heat creating near-record electricity demand and unplanned generation outages over the last 12 hours, MISO has declared (an energy emergency alert)," MISO spokesman Brandon Morris said in an email.
Morris said MISO is working with utilities and neighboring grids to "have every available resource available throughout the day."
MISO projected power use would reach 127,195 MW on Thursday, topping the system's all-time high of 127,100 MW in July 2011.