A tarp-covered pond can be used to capture methane gas as it escapes from manure, organic matter, and other sources. Dairy wastewater can be reused through custom water reclamation systems as well as a methane digestion system where energy is captured.
Straus Family Creamery President Albert Straus has tailored his farm’s energy production system. Methane digestion uses recycled water and methane captured from cow manure in this system. The methane produced from the breakdown of manure is turned into enough energy to run their whole dairy, power Albert’s car, and put power back onto the grid. Now that is some powerful poop!
Straus Family Creamery serves as a great example for low-impact energy production and water reuse. Straus’ President Albert Straus says they are “always trying to see how we can improve—from energy production, to minimizing our water usage.” This idea is exemplified by their methane digester, which utilizes cow manure from their herds to create all of the energy that their operation needs.
The creamery reuses “about ninety-four percent” of the 3,000 to 3,500 gallons of water used per day to process the milk. Water is first used to clean equipment, then to flush the barns, and finally sent out to irrigate the fields. This is the beginning of the “closed loop system” of the energy produced by the methane digester. It begins with the reuse of water and results in energy.
Once the barns have been flushed, the liquid waste is sent to the methane digester, which is a “covered lagoon”—a large pond covered by a large floating tarp. The liquid waste goes through anaerobic digestion and releases methane gas that rises up and is caught by the tarp. The methane is then “piped into the generator, and used as fuel in the generator.” It produces electricity and heats water. The methane digester produces enough energy to run the farm, power Albert’s electric car and put energy back on to the grid!
This system was expensive to implement, but “government and non-profits can help offset the initial cost and get these systems in place.” Straus found that his contribution to the system’s installation was paid off in about “four to five years.”
There are many benefits to the methane digester system, possibly the most important of which is that it keeps methane gas—“a greenhouse gas that twenty-three times more detrimental than carbon monoxide”—out of the atmosphere. It also keeps odors down and saves a lot of money on energy bills.
As a company, Straus Family Creamery’s mission has been to “sustain family farms.” As long as the focus is kept on small family farms and animal welfare, Albert believes that they can.
“How to make a methane digester,” Mother Earth News: http://www.motherearthnews.com/renewable-Energy/methane-gas-production-zmaz73mazraw.aspx#axzz2PupP22e8
Straus Family Creamery: http://strausfamilycreamery.com/values-in-action
This project is funded in part by a water stewardship grant from the California Department of Food & Agriculture.