Texas is facing a potential electricity emergency this weekend, the fourth time in the past month the state’s grid operator has issued such a warning. The Electric Reliability Council of Texas says the grid may reach emergency conditions, from Friday at 7 p.m. local time through 9 p.m. Saturday, according to a notice posted online. Ercot currently expects to have as much as 62.7 gigawatts of power available when supplies are expected to be tightest Friday evening, about 6.3 gigawatts more than p...