BURLINGTON, Vt. (WCAX) – Making the most out of manure. Four more anaerobic digesters are coming to Vermont to help cut down on greenhouse gas emissions on dairy farms.
Anaerobic digestors reduce greenhouse gas emissions by turning cow manure into renewable energy, heat, animal bedding, and fertilizer. There are over a dozen in the state, and more on the way.
When it comes to greenhouse gas emissions in Vermont 16% come from agriculture. According to the Agency of Agriculture, a quarter of that is made up of waste storage facilities.
That’s one reason why anaerobic digesters are top of mind for Dustin Machia of Machia & Sons Dairy. “As a farmer, we’re a stewardess on the land and we don’t want to pollute and over manure and do all the things that ain’t good for the future dairy for our waterways, streams, and lakes.”
Right now they take the manure of their 1,300 dairy cows and use it as fertilizer but it comes with limitations. He says an anaerobic digester could be a vital asset giving them a stream of revenue in addition to a sometimes volatile milk industry “Being a farmer you want to be here for many years to come. Just need to find all these little waterways of revenue coming through,” said Machia.
So – how does it work?
“The manure is placed in a sealed tank, so no methane or anything escapes for, on average, about 26 days. And it’s heated up to about five degrees centigrade, little over 100 and when it’s in there cooking for this period of time when it comes out, it’s a different substance,” said Jim Muir, a developer of Agricultural Digestors
Methane comes in all shapes and sizes. Excretion has methane in it, and the breath from the cows has manure in it too. Jim Muir, a developer with Agricultural Digestors says an average dairy farm can provide electricity for approximately 140 homes.
Machia’s is one of four farms statewide taking advantage of federal grants to get the digesters to the farms. There are already 14 digesters in the state; as a result of funding ten years ago.
Muir says funding, cost, and general outreach are some reasons they aren’t more popular in Vermont.
“It’s a significant engineering and construction undertaking. And similarly, it adds another layer of management and work on a dairy farm.” But Ryan Patch with the Agency of Ag says those 14 digesters have proven to be a worthwhile investment. EPA data shows 74k metric tons of CO2 equivalent are reduced per year.
“You will keep one of these digesters running year-round. It’s not seasonal like harvesting crops. In Vermont, you can make the energy you’re wrapping these projects, and so that can be another benefit of these types of technologies being constructed on farms,” said Patch.
The goal is for the anaerobic digesters to start construction this year.