Can controlling cow poop help California meet its climate change goals?
Almost nothing goes to waste at Bob Giacomini’s family dairy farm north of Point Reyes Station.
“We recycle everything that we possibly can on the farm,” Giacomini says. “We recycle our water.” His Point Reyes Farmstead Cheese Company makes 'environmentally-friendly' cheese.
“In most cheese plants the whey goes down a city sewer or into a pond or something, so we take it in and feed it right back to our cows,” he says.
Their 400 cows even munch on excess brewers grain provided by beer-makers in Petaluma.
“We have learned how to feed cattle with a lot of these products and it’s saving me money, and most of all it’s probably doing another good thing for the environment,” Giacomini says.
Recycling everything, including cow poop
After the cows finish eating, they do what all other mammals do. They poop it out. At most dairy farms, they hose piles of cow manure into lagoons, where it sits and releases methane, which scientists agree destroys the ozone. Here, methane’s just another byproduct of farming that’s reused.
That’s because the Giacomini’s installed an anaerobic digester, a piece of technology they hope will turn all this gassy cow waste into an asset. We walk over to a feeding pen where Giacomini shows me how it works.
“They come down here and eat, and we flush all these alleyways twice a day,” he describes. “It goes down into this pit.”
Then, a conveyor belt brings the manure up from the pit, and it drops through a screen, separating the poop into liquids and solids.
The solids drop to the ground and they’ll eventually reuse those, too. The liquid gushes into a lagoon covered with thick black plastic. That turns into a strange looking balloon the size of a small house, as the stinky sludge releases methane gas.
“We capture the methane, it’s pumped off and pumped up to run the engine,” says Giacomini.
The digester’s engine burns methane gas and converts it into power.
“It goes right through the grid, and it can be fed back to PG&E, or PG&E can feed this way,” right back into the Giacomini’s farm.
California’s ambitious climate change goals
The Giacomini’s have used the digester for almost a decade, and it’s producing electricity to run half their farm. This is pretty unique. Even though milk and dairy are California’s top crop, the Giacomini’s have one of only 16 digesters in the state.
“I think that we are going to start to see a shift toward more widespread use, hopefully,” says Dr. Jeff Greenblatt, a climate scientist at the Lawrence Berkeley National Laboratory.
“Anaerobic digesters can definitely lower our overall reliance on natural gas and fossil fuels generally. It's a really good thing to do and it’s not just limited to dairy farms,” he says.
Digesters can also generate power from food waste, wastewater sludge, and garbage from landfills. Greenblatt says now is the time to address all these methane problems. Last summer the state passed one of the most ambitious climate change bills in the world, SB32.
“Essentially it’s saying that in 10 years we have to shed 40 percent of our greenhouse gas emissions for the state. I mean, it is technically possible to do,” Greenblatt says dubiously.
It won’t be easy. He says we’ll all have to start driving electric cars, use electricity to heat and cool our homes. Agriculture will have to change, too. California’s the biggest dairy producer in the U.S., andcows make up almost half of California’s methane emissions.
“Wherever we can avoid letting methane seep into the atmosphere, we should,” he says.
So when Governor Brown signed SB32, farmers knew restrictions were coming. A few months ago, Brown signed another law requiring dairies to drastically reduce methane emissions by the year 2030. That’s a huge ask for dairies. The law provides some funding for methane-busting technology like digesters, but not enough, says Michael Boccadoro, the executive director of Dairy Cares, a lobbying group.
“A large digester can cost upwards of $10 million in California. You have to figure about $2,000 to 4,000 per cow is a good estimate,” Boccadoro says.
Only one percent of California dairies use digesters, and all of themneeded some federal or state funding to build. Even after subsidies, the Giacominis in Point Reyes paid $600,000 for their digester. It can cost up millions just to hook a digester up to the grid.
“That’s a killer. That project's not going to happen if it’s going to cost $3 million dollars,” Boccadoro says.
That’s why some dairies are toying with the idea of using the methane as truck fuel instead of selling it back to PG&E, or sharing one digester with a cluster of nearby dairies. Some of the funding from the new bill could go to researching these methods, Boccadoro suggests. If the state can’t strike the right balance with the farmers, Boccadoro says, we’d just be handing part of our methane problem to another state.
“If we have a dairy that simply leaves California and starts producing milk somewhere else, the emissions move with it,” he says.
Other bad byproducts
There’s another red flag. Some environmental groups like Fresno-based Leadership Counsel for Justice and Accountability argue that the chemicals released when the methane is burned to make energy create lots of problems. Digesters at big dairy and cattle farms in the Central Valley often sit right next to low income communities. These environmentalists say funding should go towards finding other ways of mitigating methane, rather than building more digesters.
But this isn’t really the case in Marin. Bob Giacomini’s farm is small, and there aren’t many people living nearby. Giacomini wants to stay put in Pt. Reyes where his family has farmed for three generations. That’s one of the reasons he built the digester; he invested a lot of money up front, but now the digester saves him money on his power bill. He can also charge a little extra for his cheese, he says, because Bay Area shoppers like environmentally-friendly products.
“Anytime you can kill two birds with one stone that's not too bad. That’s the way we look at it. We think it’s a win-win for our pocket book, and it’s a win-win for the environment,” Giacomini says.
The new dairy methane bill gives farms until 2024 to make changes, but Giacomini is glad he built his earlier. Now it’s just another part of his farm.