Renewable Energy from Dairy Farm Manure

A New Methane Digester Comes to Northwest Washington

In a promising development for the agricultural economy, an up-and-coming Washington start-up company, is turning the dairy industry’s huge manure waste problem into a renewable energy solution. After a successful debut with a farm-based anaerobic digester in Rexville, Washington, Farm Power Northwest, with its prime contractor, the Andgar Corporation, is constructing a second methane digester near Lynden in Whatcom County.

The environmental problem Farm Power Northwest has taken on is not trivial. Each year, dairy cows in Whatcom County alone produce nearly a million tons of manure. Dairy farms store this enormous amount of waste in open lagoons where it can contaminate groundwater, and, as it decomposes through natural anaerobic processes over the course of many months, emits the greenhouse gas, methane, into the atmosphere. When you consider that methane is 21 times more potent as a greenhouse gas than carbon dioxide, the scale of the farm waste problem becomes apparent.

Methane Available to Generate Electricity
The Million Ton Problem

Farm Power, by sending the manure through an enclosed anaerobic digester, is able to accelerate and control that same natural anaerobic process. In just three weeks, the digester breaks down the manure, captures the methane to burn for electricity production, and decontaminates most of the remaining waste byproduct into a valuable nitrogen-rich fertilizer.

“Dairy farming without waste is a piece of cake,” said Mike Douma, whose farm will supply manure to the new Lynden digester. The potential energy locked inside this animal waste is immense.

If all of Whatcom County’s manure could be turned into power it could potentially produce 800,000 kilowatt-hours per day. Since the average U.S. household uses about 30 kilowatt-hours per day, the cows could provide enough methane to power approximately 26,000 homes.

Fonte:

http://nwfarmsandfood.com/index.php/renewable-energy-from-dairy-farm-manure