Our local public utility finally got their 'Green Power' offering online this last month, so we just signed up. It's only an extra $10/month for us and subsidizes wind and solar projects currently in the works. I don't believe that guarantees us renewable power personally for the future, but it's a step toward getting more of it online.
For $30 a month investment I could add another kilowatt of PV panels to my system and sell power to the grid. $30 a month is almost twice my average monthly bill now.