OMG! I have worked for the last 10 years or so at festivals (eg. Glastonbury, The Big Green Gathering) where we deal exactly with this.
My job is stage manager and performer.
We have had stages/PAs/sound desks/lighting all powered by solar, wind or pedal (seriously) power and the whole focus is on sustainable/re-newable energy use.
We have had full-on gigs -packed out- using this sort of set up.
Ask away and I'll do me best or pass you on to someone else who can help.
Here are the websites of the people I work with:
http://greenfuturesfestivals.org.uk/
http://www.coltek.co.uk/