As another heatwave hits California this weekend, a Flex Alert is being issued to combat expected high levels of energy use. As of Thursday afternoon, officials who operate the state's power grid are not forecasting any rolling blackouts like we saw last month.
“Even if we’re not forecasting blackouts at the moment, things can happen very, very suddenly,” said Eric Schmitt, vice president of operations at California ISO, which manages the state power grid.
The Flex Alert is in effect from Saturday to Monday, from 3 p.m. to 9 p.m. each day. High energy demand is expected and millions of Californians are being asked to dial back their energy usage.
"Conservation in situation like this is always welcome because we don't know — there's a lot of moving parts —there's a lot of variables" Schmitt said.
Schmitt added, for example, a fire could interrupt a transmission line, and people conserving energy can help cover any unforeseen losses of energy.
"The entire West is competing for supply going into this hot period," said Mark Rothleder, who is vice president of market policy and performance at California ISO. "We rely on what is a limited set of capacity in California and in the West."
Rothleder said part of the problem in California is that when the sun goes down, solar power goes away, but energy use is still way up.
"You need to have other resources that replace that energy that you are ramping out of at the time," he said.
Rothleder said the potential to not meet the state's energy needs could continue through the end of the month, or even longer.
"From a structural perspective we're in this transition where some of the older resources are retiring and we're transitioning to a cleaner set of fleet resources, and as we do that we need to be cognizant of the needs of the system not just at peak hour," Rotherleder said.
"We need to make sure there is enough capacity and capability to meet the demand in all hours. I think that's where we believe the focus needs to be to help address this and avoid this in the future."
Officials are not so much concerned with "peak" usage, but rather the "net load peak" — when the sun goes away.
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"For decades we tracked the peak of the day and we resourced and had capacity to handle the peak — which this time of the year occurs around 5:30 p.m. or 6 p.m.," Schmitt said. "In the case of August 14th and August 15 we had to drop some load — not at the peak actually — but at what we've been calling the 'net load peak' which occurs at about 7:30 or 8 p.m."
Schmitt said recently officials have faced this challenge of what to do when solar power goes away, but use is still high.
"That rate of change now is very different from what it was just a few years ago and that's our real vulnerability these days."
Officials are worried about high energy use from air conditioners this weekend. One tip is to pre-cool homes overnight.
