In order originally to get a fairly clear idea of the capacity factors for Renewable Energy sources Wind and Solar the data provided on Wikipedia were reviewed.
These data sets provide historic data since 1990 in Germany but only since 2008 in the UK.
These data provide installed nameplate capacity measured in Megawatts and energy output measured across the year in Gigawatt hours. The referenced do not provide directly comparable values as Megawatt input and outputs. The values were revised to Megawatts for comparative purposes, accounting for the 8,760 hours in the year.
A normal fossil fuelled power station can be rated with a nameplate capacity of about 1000 Megawatts or 1 Gigawatt.
The development of the USA, the UK and German renewable energy since the year 2000 is shown below, (note these data do not include additional German offshore wind installations in 2013):
So the 25 year investment in Germany’s the renewable energy has contributed about the equivalent from windpower of about 6 normal power stations and solar power contributes about 3 normal power stations.
So the UK the contribution from wind is now about 3 normal power stations and only about ¼ of a normal power station is provided by UK solar power.
However there is a problem in the use of renewable energy sources. The output is not dispatchable. It cannot respond to electricity demand as and when needed. For example solar power in Germany might provide up to ~20% of country wide demand for a few hours on fine summer afternoons, but at the time of maximum power demand on winter evenings solar input is virtually nil.
Similarly electricity generation from wind turbines is equally fickle, as shown for this week in July this year below:
Overall both in the Germany and the UK solar power only produces ~7% of nameplate capacity.
Wind energy in Germany has supplied only about 17% of its installed name plate capacity over the years since 1990, and in the UK the more recent results have been rather more productive at ~23% of nameplate installed capacity since 2008.