Waste In, Electricity Out: The Power of Anaerobic Digestion

By Robert Coolman, The Daily Beast.

Starting with bio-waste, companies using anaerobic digester installations can church out fertilizer, animal bedding, and tons of other organic products. 

Waste goes in, out comes…electricity? Waste-to-energy is an old idea. But less common are methods that harness the power of nature so masterfully that they can be brought anywhere, be it off the grid or in the city. If that weren’t enough, such methods cut carbon emissions, reducing the contributions of human-induced climate change.

Usually we’re used to thinking of waste coming after digestion, but to solve all these problems we’re going to have to start thinking like microbes. The secret is anaerobic digestion. Anaerobic digestion is not by virtue a blessing; it’s one of the main reasons for reducing food waste in landfills. When microbes perform anaerobic digestion it causes the carbon contained in food and other bio-wastes to decompose into methane. This is a problem because methane, as a greenhouse gas, is more than 20 times as potent as the carbon dioxide formed from aerobic digestion.