Renewable energy increase will require use of more fossil fuels

The LA Times has an informative article on the need for increased capacity reserves due to increased requirements for production from intermittent generators.

Renewable energy increase will require use of more fossil fuels - latimes.com:

Germany brags of renewable output, but...

The Delta Energy Center, a power plant about an hour outside San Francisco, was roaring at nearly full bore one day last month, its four gas and steam turbines churning out 880 megawatts of electricity to the California grid.
On the horizon, across an industrial shipping channel on the Sacramento-San Joaquin River Delta, scores of wind turbines stood dead still. The air was too calm to turn their blades — or many others across the state that day. Wind provided just 33 megawatts of power statewide in the midafternoon, less than 1% of the potential from wind farms capable of producing 4,000 megawatts of electricity.
As is true on many days in California when multibillion-dollar investments in wind and solar energy plants are thwarted by the weather, the void was filled by gas-fired plants like the Delta Energy Center.
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. 

Continue Reading at the LA Times ... and ignore the 'typically gas-fired generators' part as Europe's heavier penetration of renewables is coincident with a resurgence in coal-fired generation there.