Mark F
Believe gbaikie is talking about the % of time that a solar panel generates power on average in a typical European location.
Optimistically, this is around 25% for norther Europe and stated (by panel manufacturers) to be almost 30% for Spain, California, etc.
This means that (gas-fired?) standby plants are required to supply the load when there is no sun. These are quite flexible and can produce power when it is needed. But it adds an even greater financial disadvantage to solar and cancels out a part of the reduction in CO2 emissions resulting from the solar plant.
This is just as bad for wind farms (which points to the folly of the UK plan, as Tony B’s article points out).
The only technically (and economically) viable alternate to fossil fuel fired plants today is nuclear fusion, which appears (post-Fukushima) not to be politically viable right now.
Have the “greens” painted themselves into a corner?
Max