And this data is about 5 years old... So yes, every new plant might only be a few gigawatts, but these are sprouting up like mushrooms, and their effects are cumulative. Within 40 years we could easily be 30% renewable, cutting down fossil fuel production significantly.
Actually, we're not that far off... over 10% of the world's electricity is based on renewables:
http://en.wikipedia.org/wiki/World_energy_consumption
And this data is about 5 years old... So yes, every new plant might only be a few gigawatts, but these are sprouting up like mushrooms, and their effects are cumulative. Within 40 years we could easily be 30% renewable, cutting down fossil fuel production significantly.