The 3,800 cows at Bridgewater Dairy produce a lot of milk – and manure. But unlike any other dairy in the state, Bridgewater has the tools to turn that poop to power, all while eliminating that less-than-celebrated scent.
The dairy is the second largest consumer in its electric cooperative, but thanks to the installation of the first anaerobic methane digester on an Ohio dairy, Bridgewater is selling the cooperative 30 percent more electricity than it uses. The digester’s 64-foot wide, 200-foot long and 16-foot deep chamber churns raw manure during a three-week cycle where it converts organic material to biogas that is burned in on-farm electricity generation.
It’s a multi-million dollar investment that has owners Leon Weaver and his son Chris bearing witness to agriculture’s potential to provide the world with a significant source of environmentally friendly energy, while providing a safe, abundant source of food.
“It almost makes milk a byproduct anymore,” Leon told a roundtable of Ohio dairy farmers last spring.
As an added bonus, when all that manure goes through their entire system, the Weavers get a couple of extra products – an odorless, recycled, low-bacteria solid that is safe for bedding and a liquid that can be applied to fields with little odor or compaction. “Now you don’t really see the manure going down the road,” Leon said, noting that just a few years ago, neighbors were complaining about slow tractors pulling spreaders full of the pungent material down the road.
“It’s not fun when you hear people complaining about things, true or not, especially when you try to work as hard as you can to keep things good for your environment and neighbors,” Chris said. “That (combined with rising energy costs) was the straw that broke the camel’s back,” he said about the family’s decision to look into alternative solutions.
Even prior to discovering manure’s power-providing possibilities, Chris said they were always thinking about how to handle it. “For a part of the operation that doesn’t make a whole lot of money, it’s the No. 1 area we put our mind on,” he said.
In 2005, the Weavers visited dairy-farming friends in Indiana who had installed a digester. It piqued their interest but wasn’t a cost effective investment at the time. But with increasing energy costs and with government grants and carbon credits becoming available, they started to think they could break even on the investment.
“We thought (the decision to eventually install the digester) was a slam dunk for us,” Chris said.
The Weavers figure it will take about eight years, with the assistance of green and carbon credits, to realize a payback on the more than $2 million that is invested in the new system, but social payback will come much earlier.
“We believe this is the way a dairy should be built because it’s environmentally friendly, sustainable and palatable to neighbors,” Chris said, noting that the steep investment is a step in the right direction in making sure dairies continue to have a successful future in Ohio.
And just because the odor is out of the manure doesn’t mean the Weavers can slack off on their responsibilities. “If we spill a bit of manure on the road, we’ll take the portable pressure washer out there and wash the road,” Chris said. “We probably spend a little extra money to make sure we keep things clean around here. It’s important to us and vital to our livelihoods.
“METHANE — IT’S MORE THAN MANURE
Ohio Farm Bureau Director of Environmental Policy Larry Antosch said additional efforts are being made to harvest methane gas by capping liquid manure lagoons, which would also reduce greenhouse gas emissions from livestock farms. Efforts to harness methane gas for energy aren’t limited to just livestock manure, though. The Solid Waste Authority of Central Ohio has a fleet of vehicles that runs on methane-based gas produced from the mounds of garbage in a Columbus-area landfill, and a waste water treatment plant in central Ohio is using the methane produced by sewage to power treatment processes. Outside of the United States, Antosch said families in China and India are producing biogas in their own homes, which serves a variety of uses, including cooking.