Through all that growth, sustainability remained one of their core values. That’s why, in 2012, Mitch Moorlag, the Brandsma’s son-in-law and general manager of the dairy, made the decision to install an anaerobic digester on the farm. It was a large investment for the farm, but one that they see as worthwhile.
“Being willing to take that risk allows us to be sustainable dairy farmers from one generation to the next,” says Mitch. But how does this technology work, and what are the benefits?
The manure produced by the cows flows into a large, sealed tank. In that tank, microbes that thrive in areas without oxygen (“anaerobic”) break down the manure, and in the process release biogas, a combination of methane and other gases. That gas is then used to run a generator producing about 544 kilowatts of energy, or enough power for 250 residential homes. The farm also receives carbon credits for this, since the methane that is combusted before it makes it into the atmosphere, where it would otherwise act as a greenhouse gas 28 times more potent than carbon dioxide.
The remaining manure is then separated into solid and liquid components. The solids are filtered and used as a soft, fibrous bedding for the cows. The liquids, which have a high concentration of nutrients, are used as an organic fertilizer for the crops that feed the cows.
The result is a system that captures and recycles carbon, reduces greenhouse gas emissions, produces carbon-neutral electricity, and allows the farm to more easily manage nutrient levels on their croplands.
Puget Sound Energy customers who are interested in using green power like what Edaleen Dairy produces can find more information about the program here.