By Chris Mooney, The Washington Post.
We’re at a time of deeply ambitious plans for clean energy growth. Two of the U.S.’s largest states by population, California and New York, have both mandated that power companies get fully 50 percent of their electricity from renewable sources by the year 2030.
Only, there’s a problem: Because of the particular nature of clean energy sources like solar and wind, you can’t simply add them to the grid in large volumes and think that’s the end of the story. Rather, because these sources of electricity generation are “intermittent” — solar fluctuates with weather and the daily cycle, wind fluctuates with the wind — there has to be some means of continuing to provide electricity even when they go dark. And the more renewables you have, the bigger this problem can be.
Now, a new study suggests that at least so far, solving that problem has ironically involved more fossil fuels — and more particularly, installing a large number of fast-ramping natural gas plants, which can fill in quickly whenever renewable generation slips.