This butter sculpture could power a farm for 3 days

Originally published on January 11, 2013 6:49 pm

For more than a week, it was the belle of the ball, the butter with no better: a giant 1,000-pound dairy sculpture that occupied the place of honor at the annual Farm Show in Harrisburg, Pa.

But after the indoor state fair shutters this Saturday, all that beautiful butter will leave its refrigerated display case and be unceremoniously dumped into a stinking pit of manure. That's because the sculpture will soon be converted into methane gas — enough to power a Pennsylvania dairy farm for three days.

The farm in question is located in Mifflintown, Pa., about 45 minutes from the state capital. It's powered entirely by the energy produced from a methane digester — essentially, a 16-foot-deep, covered pit of cow manure that turns waste into energy.

"It runs our whole entire farm," says farmer Brett Reinford, "and [creates] enough [power] for about 80 houses. So there's a lot of excess we sell back to the grid."

Here's how it works. First, the butter will be thrown into a pile of rotting fruits and vegetables and other food waste. Then the food will be ground up and dumped into the digester.

The digester's grunt work is carried out by bacteria, which feast on the food and manure inside the pit. It's heated to 100 degrees, in order to provide a friendlier climate for the microbes. As the bacteria breaks down molecules, the food and manure let off methane gas. The gas is piped away from the pit to a generator that powers the farm.

Since butter is essentially fat and fat contains a lot of concentrated energy, the sculpture will be a powerful fuel for the digester. Last year's sculpture provided the Reinford farm with about three days' worth of electricity.

"They brought it down here in one of our trucks," says Reinford. "And then we sent it through the grinder, turned it into mush. And then, eventually, it went into the digester. And of course it's 100 degrees in there, so it just turns into a nice liquid."

Methane digesters are expensive — about $1 million. But in between the free electricity generated and the income from selling power back to utilities, Brett Reinford says, his family farm will earn back its investment within three years.

That's why a growing number of farmers are installing methane digesters on their farms, and why Reinford and his father, Steve, spend so much time promoting the machine to other farmers. The only downside, Reinford says, is the risk of being pegged as "those methane people."

But he said he doesn't let that bother him too much. "It's such a good thing. We're not too concerned about that."

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Transcript

STEVE INSKEEP, HOST:

The aftermath of another show suggests a way to power all those new gadgets. The annual Pennsylvania Farm Show comes to a close this weekend, which means cows and roosters are heading home and vendors are packing up their hot sauce and mustards, which leaves one vital question. What happens to the farm show's biggest attraction - a giant sculpture made from 1,000 pounds of butter? NPR's Scott Detrow investigates.

SCOTT DETROW, BYLINE: Each year's butter sculpture has a different theme. Last year it was a kid with his cow. This year's masterpiece took 10 days to complete, and the theme is a bit complicated.

SASHA MACLEAN: It kind of looks like there's a Thanksgiving feast on the table in front and then, like, some trees out in back. And there's a guy putting the star on the tree.

DETROW: Sasha MacLean is just one of the thousands who swarmed to the sculpture's eight-sided refrigerated display case during this week's show. But what happens after the lights go off, after the crowds drift away? Like Frosty the Snowman, a butter sculpture isn't meant to live forever.

(SOUNDBITE OF COW MOOING)

DETROW: The butter sculpture's fate isn't pretty. Brett Reinford and I are looking at it. We're on his farm near Mifflintown, Pennsylvania. There's a cement pad next to the cattle barn. A truck has dumped a big pile of rotting fruit, vegetables and other food from Wal-Mart.

BRETT REINFORD: Dogs out here every day - both of them - looking for cheese mostly.

DETROW: Brett Reinford says all of this food waste is going to be turned into energy in a methane digester. Next week that beautiful butter sculpture will be dumped here as well, along with the key ingredient, manure.

REINFORD: It runs our whole entire farm and enough for about 80 houses. So there's a lot of excess that we sell back to the grid.

DETROW: Here's how it works: Reinford and his father Steve grind up the food and dump it into the deep covered tank of cow manure, where everything is heated up and stored for 20 days. Yeah, it smells exactly how you'd think, but that smell means the pit is generating methane gas, as bacteria inside feast on the manure and produce.

(SOUNDBITE OF MACHINERY)

DETROW: And the digester collects the methane gas and pipes it to a nearby generator, which powers the Reinford farm. Since butter is essentially fat and fat contains a lot of concentrated energy, the sculpture will be a powerful fuel for the digester. Last year's sculpture provided Reinford's farm with about three days worth of electricity.

REINFORD: Yeah, they brought it down here in one of our trucks. And then we sent it through the grinder there, turned it into a mush. And then eventually it went into the digester. And of course it's 100 degrees in there, so it just turns into a nice liquid.

DETROW: The methane digester solves a lot of problems for the Reinfords, and the increasing number of dairy farmers across the country who have installed similar systems. It gives them free electricity and heat and some extra income from selling excess power back to the utilities. And Brett figures since the 500-cow dairy farm is producing all that manure anyway, they might as well get some income from it. The digester has a big up-front cost - around a million dollars. But once you factor in all the state and federal grants the Reinford farm used to purchase it, they'll earn that money back within three years. I ask him, though, if he's worried his family will get pegged as those methane people, especially now that they're taking in the butter sculpture.

REINFORD: Sometimes, but I don't know. It's such a good thing. We're not too concerned about that.

DETROW: Scott Detrow, NPR News. Transcript provided by NPR, Copyright NPR.