Build cost under a thousand in materials + labor, and supplies around 20 hours of cooking fuel or 5 hours of electricity, per day. The system will function indefinitely as long as there's waste coming in--totally sustainable. Effort is also minimal, freeing up labor to focus on other tasks.
Very cool. Sure, it's not as sleek and high tech as solar panels, and there's the collection and hauling around buckets of waste and associated unpleasantness, but it's cheap, sustainable and it works.
More details at Resilient Communities >