A short rationale for Solar Energy:
All sources of energy on Earth originate from the sun; fossil fuels are derived from extinct life forms once energised by the sun. 'Renewables' such as wind and wave power result from the sun's radiation driving the climatic forces.
It would seem to make sense to utilise the sun's energy in the most direct way possible because, in harnessing any of these other sources, large inefficiencies are inevitable during their conversion to the more useful forms of heat & electricity. Capturing and making use of the sun's energy 'as it arrives' not only greatly reduces these conversion losses but avoids the production of harmful pollutants too.

In less than one hour as much solar energy arrives on the planet as the entire world population uses in one year! 
And in only three weeks the Earth will receive an amount of solar energy equivalent to the entire, as yet untapped, fossil fuel reserve.

How can we afford not to do our utmost to replace wasteful and harmful past practice with more globally appropriate and sustainable technology?
The answer is, of course, that we can't...