what I recall from university apprx 30-40% of solar energy is reflected, the remaining goes into latent heat (heating the temperature of the soil etc) and evaporation of water (the largest portion).
When I asked the professor how much actually goes to support life on earth - the answer was 'negligible' less than 1%.
or to put it another way..

according to Hubbert's peak.com the amount of

solar energy in 24hrs = total amount of oil reserves (past-future)

I should say the while pv solar conversion is not that efficient,
the solar dish mentioned above (made by stirling energy) focuses the heat on a stirling engine - and is approx 40% efficient (Id have to double check) but that's what I recall reading.