There are lots of energy sources that might be called “renewable,” and lots applications for renewable energy. Clearly not all are equally good.
In total, the three categories [Renewables] amount to 8.5% of world energy supply. If growth continues at today’s rate, it will be a very long time before renewable energy supply can be expected to amount to more than 10% or 15% of world energy supply.
See on theenergycollective.com