Curtailed electricity in California during 2016 was greater than the output from any one of those towers. Photo by James Ulvog.
The routine surge of electricity during the late morning and early afternoon in California is disrupting the electricity system. Matching the excess production of electricity during the day with highest use in the evening is going to be expensive for consumers.
The underlying issue is solar is neither reliable nor dispatchable. The issue is beginning to be a problem and will get far worse.
3/5/17 – Wall Street Journal – How California Utilities are Managing Excess Solar Power – There is so much solar power in California that when the sun is bright, there is too much electricity and it must be sold cheaply just to get rid of it. Then, when the sun goes down and demand goes up after people get home from work, there isn’t enough electricity and the spot price goes sky high.
Article says that during the day, the wholesale spot price of electricity frequently shrinks to zero. Occasionally the wholesale spot price can hit $1,000 a megawatt-hour after dark. That would be about a dollar a kilowatt. $1.00.
At the end of the article there is a comment that on 178 days in 2016 the wholesale price went negative. The spot was below zero. The solar plants in California had to pay someone to take the excess electricity. I wonder what that does to the bottom line at Ivanpah? (That is a rhetorical question. – Impact on them is zero because I think they are on a multi-decade fixed price contract.)
Huge battery plants can store electricity during the day and discharge at night. That is expensive. Article says the price ranges from $285 up to $581 a megawatt-hour, which is in contrast to a natural gas peaker at $155 to $227 a megawatt-hour. That is around twice as expensive.
3/18/17 – David Danelski of Press-Enterprise at Daily Bulletin – Here’s how California ended up with too much solar power – The amount of solar power now online in California is so high that it is disrupting the electricity market.
The impact of so much solar capacity shows up at two times during the day.