I’ve been following Valentina Karga’s project for a few years - she explores and experiments with small-scale, individual/community-level projects for food production, waste cycles, housing/structures and energy.
See for example a few posts & links on biogas:
http://berlinfarmlab.tumblr.com/post/35833050059
http://www.homebiogas.com/tevagastrade.html
I will get in touch with her and see if she’s interested in joining our event.