Turning waste into energy

In an agricultural state like Iowa, generating electricity using animal and industrial waste seems like a logical, promising idea.

Experts say converting manure to energy can help agricultural producers manage soil nutrients, reduce odors and protect water quality.

Anaerobic digesters help the environment by reducing the amount of greenhouse gasses released into the atmosphere. One such system at Amana Farms also is diverting industrial waste from landfills.

Communities, energy companies and agricultural producers across the state should pay attention to that project. If it proves to be cost-effective, such a system could help Iowa take a leap forward in environmental protection and energy independence.

Iowa Power Fund board members and officials from the Iowa Office or Energy Independence toured the The Farms to Fuel anaerobic digester system near West Amana last week. The Iowa Power Fund provided about $1 million in funding to the $4.9 million facility, which became operational last year.

The system uses cattle manure and industrial waste to generate methane biogas which powers four electric generators - producing between 10 and 15 percent of the Amana Service Co.'s base load of electricity.

It is one of only three anaerobic digester systems in Iowa, and one of only 125 energy-producing biogas systems operating at commercial livestock farms across the country, according to the U.S. Environmental Protection Agency.

Those systems produce energy using gasses produced by decomposing manure - methane, mostly. The gas is captured, then transmitted to an electric generator, boiler or other combustion device.

Together, the country's anaerobic digesters produce enough electricity to power more than 327,000 homes, and prevent the emission of about 36,200 metric tons of methane each year, according to AgSTAR, a joint effort to promote methane-recovery technologies by the EPA, the U.S. Department of Agriculture, and the U.S. Department of Energy.

AgSTAR recommends anaerobic digesters for their energy and environmental benefits.

As farms grow larger, liquid manure-management systems - like storage lagoons, ponds or holding tanks - are becoming more widespread. But those oxygen-free environments generate more methane than dry-form manure, AgSTAR reports.

Anaerobic digestion systems can better control odor, reduce greenhouse gas emissions and protect water quality.

Capturing that methane for energy keeps it out of the atmosphere, reduces our dependence on fossil fuels and mitigates the environmental effects of generating energy using those fuels.

That's a win-win-win for Iowa's farmers, energy consumers and generations to come.