Cover story of this week's Economist magazine. Comes with a cute graphic cover. The secret? Between heavy subsidies and falling costs, a lot of solar cells and windmills have been installed. Once installed, this equipment runs whenever the sun is up or the wind is blowing. So on a sunny breezy day there is plenty of juice, and cheap juice at that, and the expensive central power plants have to shut down until sundown. The Economist is halfway wised up, they do understand that we need those central power plants to keep the lights on after sundown. The problem as they see it is to find away to pay for the necessary central power plants when they only get to run and make money for half a day. The "alternate energy" is supplying power for the daylight hours.
There are a few unmentionables with the Economist. Not once does the phrase "nuclear power" appear in the multipage article. The Economist is virtuously anti-nuclear. They do briefly mention batteries, suggesting that eventually they will be able to carry the load after dark. Not likely, anytime soon. We have been fiddling around with battery technology for better than 200 years. Best we have now (Lithium Ion) is only maybe twice as good as Alexander Volta's first copper zinc cell of 200 years ago. We need an improvement of ten times to get a battery good enough to carry the electric grid thru the night.
Another unmentionable was "fracking" In North America, the frackers are producing so much cheap natural gas that the electric companies have given up on nuclear and coal because natural gas is cheaper and cleaner than coal. But the Economist can't breath a word about that because fracking is a dirty word in Europe.
The Economist wants, but doesn't quite say so, is government subsidies for central power plants to keep them on line for backup when the sun is down and the wind stops blowing.
Simpler and cheaper would be to drop subsidies for "alternate energy" and drop "net-metering" which forces power companies to pay "alternate energy" producers for juice they don't need. But the greenies would freak..