LOCAL POWER SURGE

A central Minnesota community looks at its renewable energy opportunities

By E. M. Morrison
 

Little Falls, Minn. –
 

There is a saying that all politics is local. The same might be true for renewable energy.
 

As ag-based fuels replace traditional fuels, “the energy for each community is going to come from the surrounding area,” says Cecil Massie, a renewable energy expert. “So a renewable energy economy will be local.”

A central Minnesota community is taking the first steps toward that future. Little Falls is exploring ways to meet its power needs with locally-produced green energy. A feasibility study will survey the city’s renewable energy resources and identify local markets for alternative power.

The $44,000 study is funded by AURI’s Center for Producer Owned Energy, the City of Little Falls, Initiative Foundation and the Central Minnesota Ethanol Co-op. Massie, a senior engineer at the Roseville-based engineering firm Sebesta Blomberg, will lead the study.

Sparked by gasification
The project was sparked by Central Minnesota Ethanol in Little Falls, which recently installed a biomass gasification system to run its 20-million-gallon corn dry mill. CMEC is the first American ethanol plant to switch from fossil fuel to biomass gasification, says Michael Sparby, AURI project director. Today, nearly all ethanol plants run on coal or natural gas. But biomass gasification could become the standard for the next generation of ethanol plants, Sparby says.

CMEC’s gasifyer converts about 280 tons of sawdust per day into synthesis gas, a low-Btu substitute for natural gas. The syngas fuels CMEC’s ethanol production and distiller’s grain-drying facilities. It also powers a 1.1 megawatt steam turbine, which generates about a third of the plant’s electricity.

Wood gasification allowed CMEC to cut its emissions and meet air quality standards for less money than a natural gas system, says plant manager Kerry Nixon. CMEC shut off the natural gas, replacing it with forest and urban slash wood and lumber industry tailings — waste materials that are typically
landfilled. A 10-year wood supply contract has stabilized the plant’s energy costs, Nixon adds. In the future, the plant may also gasify distiller’s grains.

Envisioning energy
Little Falls, in Morrison County, is a farming community of about 8,100. Agriculture is the largest industry, says Carol Anderson, Morrison County economic developer. The county ranks third in the state in dairy production and is in the top quarter for farm cash receipts. The city also has a robust manufacturing sector, which includes Larson Boats, and a growing high-tech sector.
 

Little Falls business leaders can envision a variety of ways to use CMEC’s excess power, Anderson says. The plant’s 300-degree hot air, which is now going up the stack, could heat a community
swimming pool, for example. A heating and cooling district for the nearby industrial park is also a possibility.

“Greenhouses are another thing we’re looking at that could use the plant’s CO2 and heat,” Anderson says.

MORE ENERGY IDEAS

CMEC’s biomass gasifyer is just one potential source of alternative energy for Little Falls, Anderson says.

The city is also investigating other local, renewable energy resources. For instance, the sanitary landfill could be tapped for methane — something that many communities are already doing. “We’re also looking at our large dairy operations as sources of methane,” Anderson says.

There’s even talk of forming a municipal utility to sell biogas, she adds. Little Falls is seeing a lot of residential housing growth along U.S. Highway 10. “If a utility were formed, I could see it serving these new residential developments.” Massie’s engineering study will analyze the feasibility of these and other
renewable energy scenarios for Little Falls.

Meanwhile, high oil and natural gas prices are igniting strong interest in alternative power, Massie says. “I get at least one call a week on biomass gasification.” Nixon agrees. “We’ve had a lot of people inquire about what we’re doing here.” Other Minnesota cities, including Madelia and Morris, are also looking at community-wide renewable energy projects, Massie adds. “It’s really exciting.” ■