Farm unleashes cow power

Methane from animal waste being put to good use in various ways

By ROBYN L. MINOR, The Daily News, rminor@bgdailynews.com/783-3249
Monday, January 4, 2010 11:37 AM CST

Miranda Pederson/Daily News Organic Alchemy’s David Emmerich (from left), assistant Western Kentucky University farm manager David Newsom and Nathan DeKemper, a student farm worker, talk about the organic alchemy greenhouse at the farm.

An experiment at Western Kentucky University to reduce the odor from cow manure and find other uses for the waste could lead to a permanent facility that produces enough electricity to power most of the university’s farm.

Right now, farm workers take the manure from just two cows, mix it with water and put it into a digester, which circulates the liquid from a tank and through eight other containers floating in a pond below the bed of a greenhouse. After 21 days, the end product is something with little to no smell that can be sprayed on fields for fertilizer, according to David Emmerich of Organic Alchemy in Smiths Grove, who developed and patented the digester.

Now, the methane produced from the digesting process is burned off about once a month, but in a larger scale operation the gas could actually be used to produce electricity, Emmerich said.

On Thursday, the interior of the greenhouse was relatively warm - warm enough without electric-generated heat for winter plants. The circulation of the liquid waste through tanks warms the surrounding water to about 85 degrees, according to David Newsom, assistant farm manager for Western.

“We’ve got this warm pond, we may as well use it,” said Newsom, who would like to grow tilapia in the water. “Then we’d have a fish fry for farm workers.”

The end product from the manure has already been saving the farm money.

“They bought this organic fertilizer in Louisville for $200 and it lasted about 11 days,” he said. “They used this stuff all summer long for free.”

Newsom said they hooked up a drip irrigation system to rows of tomato plants, which turned out just as large and tasty as the tomatoes grown with the expensive stuff.

Emmerich sees endless potential for the system. Emmerich’s partners now are writing a business plan; then he and university representatives will look for grants to install a large scale model at the university that would process the manure of about 250 cows, about the size of its herd.

The greenhouse now stands 24 feet by 36 feet. One large enough to house the digestion system needed would be about 44 feet by 72 feet. A grid over the top of the pond could be used to place plants on.

“This could really extend the growing season,” he said.

Farmers with greenhouse operations now may not be able to use their houses year round because of the high cost of propane or other heat. But installing a digester could provide them heat for free, use up cow manure and produce an odorless fertilizer.

“And we think a digester the size we are talking about could supply enough electricity for what the farm uses, outside the expo center,” Emmerich said.

Blaine Ferrell, WKU’s dean of Ogden College of Science and Engineering, said the university has been talking to a Cynthiana tomato farmer who grossed about $250,000 a year from the fruit he grows in four greenhouses. Ferrell said there is a great potential for savings for him in using a large scale digester that would produce heat for the greenhouses and a product to fertilize them.

Emmerich said he wants to encourage cooperative arrangements between such growers and livestock farmers, so the cost of a system and its benefits could be shared.

“We are looking at a whole systemic approach to farming,” Ferrell said. “It’s nothing really new. But after it goes through the digester, the waste is pathogen free. We can separate the solids from the liquid and char the solids so they are totally inert. We want to develop a balanced nutrient approach to see what we need to mix to produce a marketable product.

“We are looking at using all parts of the waste. Once we get a larger system, we can show farmers how to make more money with each cow, so we will use this as a demonstration project. We want to try to do it in a cost-effective manner so any farmer can do it.”

With a larger digester, the university also may try to grow algae in the warmed water and then perform experiments to see how much oil can be extracted from the algae to ultimately produce energy.

“There are other digesters out there ... but what makes this one good is that it runs continuously and you don’t have to clean it out,” Ferrell said.

He thinks chances are good that grants can be found to fund the project.

“There is money out there right now,” he said. “We should know by the spring if we will get the money.”

At the same time working to install a large scale digester at Western, Emmerich said he hopes to work with a large scale dairy farmer in the area who already is using liquid manure in his farming operations.

“I think we can produce these for about $150,000,” he said. “That would make the payback in eight to 10 years.”

Newsom is excited about the potential for Western’s system.

“It can help fuel these other projects (including algae growing) and be a great demonstration project for farmers throughout the region or even nation,” Newsom said.

And there is the added benefit of being able to produce energy from cows, animals some say are a source of increased greenhouse gases through methane they release.

— For more information about the digester go to www.organic-alchemy.com