Cool Fuel: Airing the Idea of a Neighborhood Anaerobic Digester

Madalyn Cioci
Linden Hills Power & Light board member

In the grand scheme of halting climate change, Linden Hills Power & Light (LHP&L) isn’t on par with a national carbon cap. But this group of community residents now jokingly call themselves utility executives and their ideas are turning heads around the Linden Hills neighborhood of Minneapolis and beyond.

In 2006, the group began brainstorming how to reduce climate change and build community in the process. They combined forces with a local biomass consultant and started talking trash. That is, they started considering gathering neighborhood organic waste to feed a small, local anaerobic digester to produce heat, electricity and/or transportation fuel. Basically, they hope their rotting rinds will displace some fossil fuels.

Why anaerobic digestion?

In the anaerobic digestion (AD) process, specialized bacteria decompose organic matter (leaves, grass, all food waste-including meats and oils, pet waste, and non-recyclable paper like pizza boxes, napkins, paper plates, waxed cartons) in an oxygen-depleted environment. The result is methane gas and excellent compost, both of which can be used for beneficial purposes. AD, in use around Europe, in Toronto and elsewhere, reduces the volume of waste going to landfills and emissions of greenhouse gasses. The key to using organics in urban areas is the “anaerobic” part. In the air-tight system, odor is eliminated, unlike most digesters on farms. Compared to landfilling and incineration of organic waste, anaerobic digestion actually creates a net absorption of greenhouse gasses.

“The time is right for this project”, says Executive Director Felicity Britton. “The technology can be scaled to small settings and collecting organic waste curbside is gaining in popularity around the metro area. Our neighbors have been asking for something concrete they can do, together, to deal with climate change, and this is a great option.” Hennepin County already collects organics in Wayzata and several High Schools. Collecting organics could increase the current 35-40% recycling rate to about 75%, vastly reducing needed landfill space.

LHP&L has secured $30,000 from the Minnesota Pollution Control Agency and $45,000 from the Department of Commerce for an initial feasibility study and beginning design work. This will help answer key questions such as where to put the digester and what its primary product should be: heating and electricity, transportation fuel (possibly for school buses), or something else. Minneapolis’ Director of Solid Waste is supportive and planning to pilot curbside organics pick-up in the neighborhood soon.

For more info or to join the community discussion visit lhpowerandlight.org.

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