Customers refuel at a gas station in Concord, California. Photographer: David Paul Morris/Bloomberg Californians can’t get a break. A dangerous heat wave is raising the risk of blackouts in the state on top of perennial drought and fires. And now, after enduring record pump prices in June that were much higher than the national average, Californians face surging gasoline costs again at the end of the summer travel season when they typically fall. Pump prices jumped by more than 5 cents a gallon overnight in San Francisco and Sacramento, according to auto club AAA, and record wholesale premiums signal they could rise further. At the state level , retail prices average $5.306 a gallon, almost 3 cents more than the previous day. The confluence of bad news highlights how vulnerable California’s energy systems are to supply disruptions. The state is an energy island, cut off from crude and fuel […]