Some Texas power plants unexpectedly went offline last week; grid operator says it still doesn’t know why Fri, 06/25/2021 - 12:00am Last Monday, Texas’ main power grid operator asked Texans, mid-heat wave, to turn their thermostats to 78 degrees during the ...PLEASE LOG IN FOR PREMIUM CONTENT. Our website requires visitors to log in to view the best local news. Not yet a subscriber? Subscribe today! Read more about Some Texas power plants unexpectedly went offline last week; grid operator says it still doesn’t know why