Manure-to-gas plant promises relief for Texas' dairy country

STEPHENVILLE, Texas — It has the makings of an environmental home run: A project that reduces global warming gases, provides a green alternative to fossil fuel, creates organic fertilizer and helps dairymen get their cow manure out of the polluted North Bosque watershed in Texas.

A company called Microgy Inc. expects its new manure-to-gas digester in the heart of the northern Central Texas dairy country to do all that — and make a healthy profit. The company recently opened Huckabay Ridge, which it calls the largest renewable gas plant in North America, possibly the world.

Eight huge tanks next to a composting operation mix the manure from 10,000 cows with food waste and convert it into flammable methane. The gas is scrubbed clean, compressed and inserted into a natural gas transmission line, then shipped all the way to Austin, where the Lower Colorado River Authority burns it for electricity for as many as 10,000 homes. That works out to about one home per cow.

Burning the methane is better for the environment than allowing it to escape into the air, because methane has a global warming effect 21 times that of carbon dioxide, which is created when methane is burned.

Microgy, a subsidiary of the publicly traded firm Environmental Power Inc. of New Hampshire, has spent between $12 million and $18 million on the facility, without significant public subsidies, company officials said. The firm has permitted or built biogas digesters at three locations in Wisconsin, Nebraska and California.

“We’re absolutely the pioneers in this,” said Pat Chase, a Microgy regional manager based in Sulphur Springs, Texas. “The fact that we can take manure and other materials and digest them and make viable natural gas means the market is really unlimited. It’s only limited by how many cows and hogs you have in feedlots.”

City of Waco officials, who have been fighting dairy waste pollution for a decade because of its effect on Lake Waco, saw the plant as a sign of new thinking about cow manure.

“I think long term we will see more and more beneficial uses for manure,” City Manager Larry Groth said. “Technology is going to drive that industry. The time is coming when producers that have done such a fantastic job on the milk side are going to do the same thing on the waste side.”

Microgy officials say the Erath County site made sense in several ways.

It’s close enough to a major gas transmission line that the company could afford to connect to it. Microgy removes carbon dioxide and corrosive hydrogen sulfide, leaving a gas stream that is 99 percent methane, officials said.

“Because we’re new to the industry, we’re under the microscope, and so we make sure we are not putting impurities into the gas line,” plant operations director Mike Newman said.

Supply was another factor. The Stephenville area, known as the Cross Timbers, is the most concentrated dairy region in Texas, assuring a bountiful manure supply. The site itself is shared by Producers Compost, a manure composting operation that receives manure from about 15 dairies. Microgy digests manure from the compost operation, then gives back the finished product — a weed-free compost that is higher in plant nutrients than conventional compost, officials said. The compost is sold outside the watershed, the company said.

The digester also uses industrial food waste, including fat and grease, which accelerate the anaerobic bacteria that turn the manure into methane.

Microgy officials are seeking to build a second plant near Dublin, close to the divide between the Leon and Bosque watersheds. They hope to qualify for government renewable energy credits that would make the projects more profitable.

Even without the credits, Chase said the operation could stay in the black as long as natural gas prices stay above $4 per 1,000 cubic feet. In the last year or so, prices have been stable at between $5 and $7.

Chase said more incentives could give the budding biogas industry a kick-start.

“We’re working toward getting legislation that will benefit the biogas industry like the ethanol industry,” Chase said. “As soon as they pass that, everybody and their brother is going to be doing this.”

Indeed, Microgy isn’t alone in its interest in turning manure into gas in the Stephenville area.

A company called Realenergy is reportedly developing a plant near Dublin that would convert manure into gas, then generate electricity on site.

Two years ago, Hico dairyman Keith Broumley built a $1.6 million demonstration methane digester for his dairy using public and private funds. However, the system is on hold because of technical problems, said a spokesman for the Texas Farm Bureau, which was involved in the project.

Downstream, the city of Waco is turning human waste into methane at the regional wastewater treatment plant and using it for gas and electricity at the plant itself, utilities director Rick Garrett said. He said he hopes eventually to increase production so the city can sell electricity into the grid.

Travis Brown, a renewable energy specialist with the state Office of Rural and Community Affairs, said the Microgy project is leading the way in showing how agriculture can be both profitable and environmentally sound.

“The Microgy project holds tremendous potential to solve a problem that the livestock industry is facing across the country,” he said. “There are an awful lot more dairies that would probably like to have a way to get rid of their waste. We need more projects not only in Erath County but in other parts of the state.”

Brown is an Erath County native who fought dairies over pollution issues in the early 1990s, before the city of Waco got involved.

Now Brown is co-chairman of the Texas State 25x’25 Alliance, a coalition of agencies with the goal of increasing renewable energy supplies. On a recent bus trip the group took to the Microgy site, he found himself in the company of a former foe: Texas Farm Bureau spokesman Ned Meister of Waco. Before the tour, both Meister and Brown spoke to the group about the need for environmentalists and the dairy industry to work together to find creative solutions to the North Bosque watershed issue.

“Back in the early ’90s, we were on different sides of the fence,” Brown said. “Now, 15 years later, here we are working on the same side of the fence. That’s a good feeling.”