Nationwide heat wave puts electric grid to the test

The entire country is in the red (and orange) today. At 10:20 am, it was hotter in Minneapolis than southern Florida and the only places that looked remotely comfortable were all on the Pacific coast. Those temps don't just strain your patience. They also strain your electrical grid, as millions of Americans simultaneously crank up their air conditioners and test the grid's ability to match supply of electricity with demand for it. For grid controllers, a day like today is akin to the Super Bowl. Will there be brownouts? Blackouts? Awkward flickering? Place your bets. The peak in demand will happen later this afternoon.