The Texas Power Grid is urging generators to come back online and stay online through Monday because of a demand that will likely break records this weekend. Professor Bob Hebner at the University of Texas says there are concerns about rolling brownouts because no system is perfect. The national weather service is predicting triple digits across Texas. The hottest weather will be in the big cities, with the most people cranking down their air conditioners. A spokeswoman for ERCOT said the agency expects sufficient generation to meet forecasted demand.