Threats of rolling blackouts continue, heat will return next week

California is on standby, until 11 p.m. for possible rolling blackouts if relentless demand for power is not tempered.

When it gets really hot for days on end, so-called heat storms can cause these rotating outages. California's power grid operators say demand is about two percent higher than Monday and without serious conservation right now, expect widespread rolling blackouts.

Where California gets its power from is a big reason we're in this dilemma. Since our last mega heat wave, more than a decade ago, California has taken about 15 to 20 percent of its natural gas fueled power plants out of service, plus the impact of the huge San Onofre nuclear power plant.

They have been replaced with solar and wind, which though super cheap and green, cannot just be switched on like traditional power plants says Berkeley Haas Business School energy economist Severin Borenstein.

"Wind and solar are constrained by whether the wind is blowing and whether the sun is shining. They are not something you can say, "We want your full capacity," said Professor Borenstein

So, grid operators told PG&E and other utilities to warn of possible outages.

"That information was information we provided also on Sunday and Monday and ultimately ended up not being the case. But, we wanted to alert our customers at least to the high probability of it because we would like to have the opportunity for them to prepare," said PG&E spokesman Jeff Smith.

As demand was skyrocketing on Monday, at 3 p.m., customers finally paid attention to conservation pleas. "We had a dramatic lowering of the demand curve like we've never seen before and we believe it's all contributable to the great work people did to conserve. We haven't seen heat like this since 2006," said power grid CEO Steve Berberich.

"Voluntary calls for conservation help occasionally, but, there's a lot of evidence that if you consistently ask people to voluntarily conserve, you get conservation fatigue and people stop conserving as much," said economist Borenstein.

So blackouts, Tuesday and Wednesday, even as heat returns next week, could still happen.

"The most important hours are 6 p.m. to 9 p.m. That's when the demand is very high and the solar rolls off," said Borenstein. Since blackout risk remains, PG&E has just out up a web site where you type in your address and learn if or on not you are schedule for an outage.