Environment & Science

Stinky Renewable Energy Source Creates Smog

The methane gas released from cow manure is a valuable renewable energy source for many dairy farmers. But the gas creates smog, so farmers trying to reduce one type of pollution are, in fact, creating another.

California is the nation's largest dairy state, which means that while cows there produce a lot of milk, they also produce something else -- methane gas.

And methane is a powerful contributor to climate change.

Some farmers, at a great up-front cost, are capturing the gas and using it to create renewable electricity for their farms. But by solving one environmental problem, they're running headlong into another.

Double-Edged Sword

For nearly 100 years, John Fiscalini's family has run a dairy farm in California's Central Valley.

And like any other cows, the ones on Fiscalini's farm produce a lot of manure -- about 100 pounds a day.

That manure fuels some cutting-edge technology. Every few hours, it's flushed, washed out of the barn and collected in large concrete tanks nearby. The tanks trap methane gas that's released from the manure.

"The gas bubbles up to the top, and there is a pipe that basically comes from each of the two tanks," Fiscalini says.

The pipe goes to a nearby generator, which looks like a massive car engine. And the generator uses the gas to produce electricity -- enough electricity to run the whole farm.

"Our farm is completely renewable in the fact that we don't buy electricity from outside sources," Fiscalini says.

But this is where his problems started. Like any combustion engine, his generator produces air pollution, which contributes to smog. So, even though the digester is reducing one kind of pollution -- greenhouse gases -- it's contributing to another -- smog, which state air officials are trying to prevent.

Air Quality Before Climate Change

After having spent $4 million on his digester, Fiscalini had to add a $200,000 pollution control device. He thinks his experience has discouraged other dairies from investing in digesters.

"There [are] not many people who wish to follow in my footsteps and build something like this given the fact that they are not economical to build and operate, and most importantly, there will be two agencies that will be all over you," Fiscalini says.

Being asked to spend money to control pollutants is not an unusual thing to hear from any industry, says Dave Warner, who works for one of those agencies -- the San Joaquin Valley Air Pollution Control District.

Warner says air pollution here is consistently higher than federal law allows, and asthma rates are among the state's highest. And although California has set some ambitious climate change goals, he says those goals shouldn't come at the cost of air quality.

"It's been recognized from day one," Warner says. "There should not be sacrifices made to the protection of public health in interest of reduction of greenhouse gases."

Two other air districts in California have followed San Joaquin Valley and set similar pollution controls, which is good for local air quality, but it leaves farmers back where they started.

"Good intentions but bad result," says Allen Dusault of Sustainable Conservation, an environmental group in San Francisco. He says interest in digester projects has waned, especially given the financial downturn.

"We had a lot of private capital looking to come in and build these systems," he says. "And I used to get several calls a week asking me about the different technologies and about the different companies. And today I get almost none."

Digesters A 'Tough Sell' In California

Dusault says dairy states like Wisconsin and New York are building digesters at a much faster rate than California because those states don't face the same regulations. He says to get things moving again, affordable pollution control technology will need to be developed.

Fiscalini agrees that until that happens, the business case for a dairy digester is a tough sell.

"I really believe it is the right thing to do," Fiscalini says. "It simply needs to be made more available to the masses. The current series of laws that we have don't make digesters profitable."

California state air officials are now taking a look at how dairy digesters are regulated. Copyright 2010 KQED Public Broadcasting. To see more, visit http://www.kqed.org.