Solar energy in figures: Germany is king

In one hour, the sun casts upon the earth more energy than we, the whole of humankind, consume in a year.

It is a favourite of solar energy enthusiasts, as is the truism that all renewable energy sources - wind, falling water, ocean tides, biomass - are in fact converted sunshine.

Yet for all the abundance, solar energy, the light and heat that radiates from the sun, remains largely untapped.

Of all the energy consumed in Europe in 2010, according to Eurostat, only 0.2 perc...