“The extreme heat that sent electricity demand and prices surging to record levels in Texas on Monday is threatening to do it all over again on Tuesday. [On Monday,] [w]holesale power prices jumped 36,000% to average as much as $6,537.45 a megawatt-hour across the Texas power grid.”

https://www.bloomberg.com/news/articles/2019-08-12/searing-texas-heat-pushes-power-prices-to-near-record-levels