How Manure-to-Energy Projects Make the Best Out of a Stinky Situation

In Vermont, seven dairy farms are transforming millions of gallons of cow manure into electricity through the Cow Power project. Over the past seven years, these farms have installed anaerobic digesters on their farms and shoveled in their cows’ waste. The digesters separate methane natural gas, out of the manure, using it to power an electricity-generating turbine.

Waste-to-energy projects like this one are making the best of a bad situation by reusing the dregs of industrial processes that would otherwise drift into the environment. Just as manure can become electricity, gases pouring out of steel plants can become jet fuel. Plain old waste—the stream of garbage that would normally end up in a landfill—can also power people’s homes. As long as there’s no other option for disposing this excess material, waste-to-energy projects can make sense. But they also depend on the continued existence of large-scale, polluting industries and can do more harm than good.

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The steel industry, for example, has few other options for disposing of its waste, so when planes fly on secondhand carbon, they decrease the total amount of pollution dumped into the atmosphere. And industrial dairy farmers have more manure than they could ever need: if they don't burn it to create electricity, the methane from manure leaks directly into the atmosphere.

For waste-to-energy to make economic sense, though, projects generally needs government support, like most renewable energy initiatives. In Vermont, 4,600 customers pay 4 cents extra for each kilowatt-hour of Cow Power generated by the farms. That extra contribution adds up to almost $500,000 a year for the whole program, in addition to the $2 million each farm invested in equipment. In a new study of the program, a team of researchers at the University of Vermont found that farmers would not be able to commit to the program without government grants and other subsidies.

Government support for waste-to-energy isn’t always justified, though. In Maryland, the state government has decided that waste-to-energy projects can contribute to meeting renewable energy goals, just as wind and solar do. But the waste-to-energy projects already under construction in Maryland generate more pollution than coal-fired power plants, according to an analysis by the Environmental Integrity Project.

Even less questionable waste-to-energy projects take a less-than-idealistic view of the world. Waste-to-energy investments are worthwhile only if a reliable stream of waste continues to pour in. In a different agricultural system, for instance, manure could be recycled as fertilizer and turned back into vegetables, instead of being harvested for methane. For that system to work, though, this country would probably need to depend on fewer cows: we’d have to drink less milk and eat less yogurt and cheese. Supporting waste-to-energy projects means betting that large-scale changes like that are unlikely to happen.

Photo via (cc) Flickr user Joost J. Bakker IJmuiden