Oh boy, was this ever an "I told you so moment".

http://articles.latimes.com/2012/dec/09/local/la-me-unreliable-powe...

 

One of the hidden costs of solar and wind power — and a problem the state is not yet prepared to meet — is that wind and solar energy must be backed up by other sources, typically gas-fired generators. As more solar and wind energy generators come online, fulfilling a legal mandate to produce one-third of California's electricity by 2020, the demand will rise for more backup power from fossil fuel plants.

The cost to consumers in the years ahead could be in the billions of dollars, according to industry experts. California's electricity prices are already among the highest in the nation and are projected to rise sharply in coming years. At the moment, the need for reserve power isn't considered a cost of renewable power, though consumers have to bear its costs as well.