If you want to get off of fossil fuel, what are you going to use to power your new slim energy-fit lifestyle? This graph shows world power generation potential (based on what we can practically get with current technology) from solar and other renewables.
These numbers are from smart guys at Caltech and MIT. Other researchers have reported a little higher numbers for wind...but even so, who's the overwhelming winner?
Take advantage of any renewable sources that are suited to your specific location...but globally, let's go solar!