Anaerobic Digesters Podcast Mini-Series

In the first episode of this series, we introduce anaerobic digesters and explore why using this technology can support important environmental goals like greenhouse gas emissions reduction, water quality improvement, and renewable energy generation.

We talk to Chris Cox from the Montpelier, VT Water Resource Recovery Facility and Eric Fitch from Purpose Energy about why some organic wastes are harder to manage than others, and Nora Goldstein, editor of BioCycle Magazine, explains how digesters can improve water quality.

Josh Kelly from the Vermont Agency of Natural Resources discusses the organics diversion laws that aim to redirect waste, including food scraps and other organics, away from landfills.

In the second episode of this series, we discuss the nitty-gritty details about how digesters work and how we get from organic waste back to useful resources like heat, electricity, and transportation.

Bill Crossman from Vermont Technical College explains the digestion process and the different biogas potential of different feedstocks. Tom Murray from Vermont Gas Systems explains how they became the first gas utility in the country to offer renewable natural gas to customers. Josh Castenguay from Green Mountain Power discusses using the benefits that biogas bring to the electric grid.

Then, Tim Taylor from the Sacramento Clean Cities Coalition talks about California’s efforts to use anaerobic digestion to produce renewable natural gas used for transportation.

In the third episode of this series, we highlight many of the environmental and economic concerns about using digesters to manage organic waste.

First, our experts explain the technical and operational challenges of digester development and operation, including nuisance complaints.

Then we hear from Patty Lovera of Food and Water Watch, with concerns that digester operation is costly and risky, particularly for farmers, and can contribute to continued use of fossil fuel infrastructure and factory farming.

Dan Bell from Agri-Cycle discusses challenges in obtaining enough feedstocks to run a digester, and the special challenge of using packaged food. Bob Spencer from the Windham Solid Waste Management District in Vermont tells us why he was unable to develop a digester, even though he may have a perfect location.

Finally, our experts discuss the Federal Renewable Fuel Standard and other incentives for pipeline injection of biogas that make it less likely to be used locally.

In the fourth episode of this series, we look at three real-world examples of digesters done right.

First, Eric Fitch discusses his biogas development company, Purpose Energy, which focuses on digesters use in the food and beverage industry, including Magic Hat Brewery.

Then, Lauren Kahle tells us about the closed-loop system at Stahlbush Island Farm, in Corvallis, Oregon.

Finally, Tim Taylor discusses the Farm to Food to Fuel to Farm initiative in the city of Sacramento, CA.

Each of these successful models uses A.D. technology to address a local waste management need, reduce greenhouse gas emissions, meet a local energy demand, and make use of their digestate as a valuable resource. We also hear from several of our experts about policy improvements they would like to see in the biogas industry in the future.