DEBRIS.COMgood for a laugh, or possibly an aneurysm

The Straus Dairy has 270 cows, each of which produces about 120 lbs of manure every day. That’s 5900 tons of manure per year. To put it in perspective, a typical cow produces 6.5 gallons of milk per day — or roughly 52 lbs of milk, if we assume that milk (like water) weighs 8 lbs/gallon. The point is that dairy farms produce 2.3 times as much manure as milk. You could even say that milk is a byproduct of the process of manure creation.

What do they do with all that crap?

The Straus family found a great answer: the dairy installed a 75 kilowatt biogas generator, aka “methane digester.” The synergy is amazing:

• the methane digester saves the dairy $5000 per month in energy costs — it will pay for itself in three years (and then, like my photovoltaic array, make free power for a long time)
• the system consumes tons of greenhouse gasses emitted from the decomposing manure. According to the Chron article, “naturally occurring methane is a potent greenhouse gas, estimated to be 21 times as damaging to the ozone layer as carbon dioxide.”
• the system “strip[s] 80 to 99 percent of organic pollutants from the wastewater” generated at the farm. (Read about the effects of agricultural runoff on the fishing industry.)

But wait, there’s more — “The Straus project is the first of 14 methane projects to receive matching funds from the California Energy Commission.” This means there are 13 more similar energy systems under construction. That’s the best news I’ve read all week.