I got an email a couple of days ago from Paul Weaton at Permies.com (http://permies.com)
He has a very rich website with lots of active forums on many topics. I spent some time exploring the Energy section (http://www.permies.com/forums/c/7/). There are discussions there of Rocket stoves, off-grid solar and much more...
For example:
• Discussions on building - http://www.permies.com/forums/c/6/
• Here's a list of the individual forums - http://www.permies.com/forums - it's quite a list!