California is under a Flex Alert, so you're asked to reduce your power consumption. Excessive heat is pushing the power grid to its limits.
Cal ISO forecasts 46,000 megawatts of power will be consumed Wednesday. Tuesday was about 44,000 megawatts.
California power operators hope to avoid rolling outages, and a Flex Alert is one way to do that.
Cal-ISO manages the grid. Spokesman Steven Greenlee says the system starts to feel the strain during widespread triple-digit temperatures.
"At 100 degrees, for every degree over that, can mean we have to generate hundreds of megawatts more in order to meet that one degree increase," says Greenlee. "And, if it's a couple of degrees, then we may even be talking about a couple of thousand megawatt more of generation."
Greenlee says to think of the power grid as a busy freeway. Transmission lines have limited capacity, just as a freeway can only hold so many cars.
Once the system reaches capacity, adding new power sources doesn't help... just as adding more cars to the freeway doesn't relieve gridlock.
The only way to free up the system is to reduce power usage.