Finding resources in the trash

New Linden Hills group looks at ways to harness energy with bacteria byproduct

It’s one of the most daunting problems facing the planet today, but a group in Linden Hills thinks it might have found a piece of the solution in their trash.

They’re calling themselves the Linden Hills Power & Light Company and, after several talks about global warming, they see a new future for their neighborhood.

Instead of coal power plants, table scraps will power restaurant kitchens, pet waste will light street lamps, and leaves and grass clippings will help heat homes.

The technology exists to generate electricity from all of those substances and other biodegradable garbage through a process called anaerobic digestion. Tiny bacteria breakdown the materials in a sealed container and release methane gas as they digest. The methane is then burned to power an electrical generator.

Anaerobic digesters are used in parts of Asia and Europe, but if Linden Hills is successful in building one, it would be the first of its kind in the United States.

The project started in January with conversation between Wild Rumpus bookstore owner Tom Braun and longtime friend, Will Steeger, the arctic explorer who has dedicated recent years to raising awareness about global warming.

“One of the issues that came up was what do we do about it,” Braun said.

Braun called on some neighbors and the group came together as a vehicle to promote energy-efficient light bulbs and a ride-your-bike-to-school day earlier this year. As they continued networking, they eventually drew in a former resident, John Madole, who works as a consultant on energy and recycling issues.

“He said quit thinking so small,” recalled Madalyn Cioci, a neighborhood organizer.

The group decided to work toward a goal of energy independence – to eventually generate all the energy Linden Hills needs from local and renewable energy sources like solar and anaerobic digestion.

The anaerobic digester would be a first step, providing heat and electricity to the neighborhood’s central business district, or the equivalent of about 30 homes.

Ken Bradley, a senior policy associate with Fresh Energy, said small movements like the one in Linden Hills have appeared around the country. It’s a conversation that should be happening everywhere, he said, even if it is drastic.

“It’s no less drastic than you and I saying we’re frustrated with health care so let’s start our own health care company,” Bradley said. “It’s really born out of a frustration with our current utilities lack of progress on global warming.”

And while Bradley is intrigued, he sees big challenges for the project.

Aware of the obstacles, Linden Hills Power & Light members gathered with a panel of experts last month above Braun’s bookstore to brainstorm logistics.

Among the unanswered questions is where to put it. The digester would take up about 2,000 square feet and stand a couple stories high. To be efficient, it needs to be situated nearby the building or buildings it’s going to serve.

The neighborhood would also need to daily feed the digester at least five tons of biodegradable trash, or about one full garbage packer truck. Its 4,000 households easily generate that much, but residents would need to separate the waste and somehow get it to the digester.

That’d likely mean setting up a separate neighborhood collection service for biodegradable garbage. The group discussed using horse-drawn carts as a cleaner and possibly cheaper alternative to garbage trucks. And they talked about creating jobs for teenagers to do the actual collection.

“It’s a very romantic notion that we’re all going to hold hands and get this garbage where it has to go,” Braun said acknowledging the complexity.

Even after the electricity is generated, the neighborhood would need a plan for what to do with the waste left over in the digester. The material makes great fertilizer, but it would be another task to remove, package and sell it.

And the neighborhood project might see resistance from the current utility company, which has a franchise agreement with the city to provide electricity.

Linden Hills Power & Light is seeking a $40,000 state grant for a feasibility study to see whether the project is worth pursuing.

 

Dan Haugen can be reached at dhaugen@mnpubs.com or 436-5088.