Biodigesters harness the appetites of tiny organisms to break down organic waste into renewable biogas and fertilizing compost.
They can be built in countless different ways, from simple plastic containers to multi-chambered, stainless steel machines, but the crucial ingredients are an anaerobic environment (one free of oxygen), and bacteria that can survive happily away from air and light.
Biodigesters can handle any organic material, though some will break down faster than others. Most frequently, they're used to process bodily waste, both from humans and farm animals.
One major advantage of a biodigester is that it's relatively free of maintenance requirements, and doesn't need a sewer system to work—making it a good solution for properties that are off the grid.