March 4 U.S. grid operators in Texas and the Midwest on Tuesday ended calls for power conservation as icy overnight temperatures warmed slightly, easing the strain on electric systems.
On Monday, the Electric Reliability Council of Texas (ERCOT), which operates the grid for most of the state, asked customers to conserve power on Monday and Tuesday as cold weather boosted demand to record levels for March.
Earlier Tuesday, about 50,000 homes and businesses in Texas were without power mostly due to icing, according to local utilities. About 40,000 customers still had no power at about 11:15 a.m. EST (1615 GMT).
In the Midwest, the Midcontinent Independent System Operator (MISO), which operates the grid, asked utilities to stop unnecessary maintenance to avoid power shortages, because frigid temperatures were driving up demand and some plants were shut for forced outages.
The MISO warning was for utilities only and did not mean the grid would run out of electricity for consumers.
MISO, the second biggest power grid in the United States, operates the power grid in 15 U.S. Midwest and Gulf Coast states and the Canadian province of Manitoba.