Last week I reported on a single Valley retail electric company that got hit with a giant bill because of spot-market prices for power that spiked during the February 2 rolling blackouts. Monday, the Electrical Reliability Council of Texas (ERCOT), the quasi-government entity that manages most of the state’s grid, released figures that show the enormous cost of the event generally to buyers of power — and, no doubt in some cases, eventually to retail customers.