It might not be as pretty as windmills spinning on a hillside or solar collectors gleaming in the sun, but cow manure could be part of the renewable energy future.
This week's convention of Western United Dairymen in Modesto featured experts on extracting methane from manure and turning it into electricity. The energy could be used on the farm, reducing costs for the farmer, or sold to a utility if it exceeds the farm's needs.
Farmers also can earn money through greenhouse gas credits. Under this system, businesses that reduce their contribution to global warming -- and methane from manure is believed to be a sizable contributor -- can sell credits to companies that are trying to compensate for their own impact on the climate.
"The key is this is methane that would otherwise be emitted to the atmosphere," said Joel Levin, vice president of business development at the California Climate Action Registry.
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This state agency tracks efforts to reduce emissions of carbon dioxide and other climate-changing gases from fossil fuels. The efforts include alternative fuel sources, such as manure and solar, and farming and forestry practices that build up carbon in plant tissue and soil.
The goal over several decades is to reduce the amount of gases trapping the sun's heat in the atmosphere, a problem that could lead to higher temperatures and reduced snowpack in California.
Methane rises into the atmosphere if manure is stored in the open lagoons that are common on today's dairy farms. It becomes much less harmful if broken down by bacteria in systems called digesters and then burned to produce energy.
So far, just 13 California farms have digesters, according to Western United Dairymen. Twelve of them feed electricity generators. The other one, just completed near Fresno, will send methane from 5,000 cows into Pacific Gas & Electric Co. gas lines, enough to serve 1,200 homes.
One of the early digesters is at Joseph Gallo Farms near Atwater, where methane from 5,000 cows produces electricity and steam for the company's cheese plant.
The system has provided Gallo with more than $100,000 worth of greenhouse credits, said Carl Morris, general manager and chief operating officer.
The credits, traded on the Chicago Climate Exchange, are worth about $4.50 per ton of emissions now but have ranged from $1 to $5 in the past four years, he said.
Another digester is under construction at Fiscalini Cheese Co., which has about 3,000 cows west of Modesto.
The dairy group also heard from Toni Nelson, business development manager for EcoSecurities, a company based in Irelandthat invests in climate-related projects. She said manure-to-energy systems are attractive to people buying carbon credits and to neighbors of the farms.
"One of the big benefits of a digester is reduction of odors," she said.
The convention also featured a discussion of conservation tillage -- growing dairy feed crops with little disturbance of the soil. The seeds are drilled through the stubble from the previous crop, a change from the frequent turning of soil on the farms.
By reducing the number of tractor passes in each field, advocates say, farmers can reduce dust, soil compaction and the cost of fuel, labor and equipment repairs. They also say they can get three harvests from a single field each year, versus two in conventional farming.
Dino Giacomazzi, a Kings County dairyman who uses the conservation tillage method, said it could help burnish the industry's environmental image.
"We really need to change people's opinions about us, because we are the solution," he said. "We are the green industry."
Bee staff writer John Holland can be reached at firstname.lastname@example.org or 578-2385.