As you know, I've shifted my focus from the part of sustainability that many think of as green to the part that addresses obesity and food addiction. But I still have great fondness and concern for those topics.
When I was actively pursuing them, I found no greater source, or concentration of information, than at the annual Building Energy show put on by the Northeast Sustainable Energy Association.
If you have any interest in this field, I could not recommend an experience more highly. Early bird registration here.