Twice a day, Keith LaLonde and his wife, Kim, trek to a shed behind their Monroe County home to fill several 5-gallon buckets with dried corn kernels.

The LaLondes aren't using the corn to feed animals. They're heating their home.

Like a growing number of homeowners in Michigan and across the country, the LaLondes have switched to an alternative heating source: corn stoves. By burning corn, the couple have cut their winter heating bill to about $800, from about $1,900 a season for propane.

"Every time I heard the (propane) furnace come on I used to cringe," Keith LaLonde said. "I couldn't believe the bills, so I looked for an alternative."

With the cost of propane and other heating fuels rising, manufacturers and dealers say demand is growing for corn stoves. They're expecting another brisk winter of sales -- one national manufacturer, Tennessee-based Nesco Inc., sold nearly 7,000 units last winter -- a sevenfold increase from the year before.

Corn stoves work like wood-burning stoves but burn dry corn kernels -- no husks or cobs. They can range in size from a large space heater to a furnace capable of heating a 3,500-square-foot house. Models that can be inserted into fire places are the most popular and range in price from $1,500 to $3,000, local dealers say.

"Last fall we couldn't get them in quickly enough," said Paul Grishkevich, a salesman at Emmett's Energy in Waterford. "We sold 60 stoves last year -- 10 times what we did the year before -- and we probably could have sold more if we had them in stock."

The stoves have proven popular among residents of rural areas and outlying suburbs, with easy access to corn growers and feed stores. Stoves use yellow dent No. 2 -- widely grown in Michigan -- the same corn used to feed animals and make ethanol.

Compared with other heating sources, such as wood, corn burns clear and relatively cleanly, industry officials said. Its exhaust, vented outside the home, often smells like roasted corn.

Burning corn, rather than oil or coal, is a more sustainable energy source because it's renewable, said Brad Garmon, land programs director for the Michigan Environmental Council.

By burning corn, consumers are taking advantage of a local source of energy, which helps reduce the pollution associated with energy transportation and production.

Of course, there are environmental concerns tied to fertilizer use and agriculture-related pollution in growing corn. And like all burning fuels, corn does emit carbon dioxide.

Despite growing demand for corn -- especially for ethanol production -- Michigan is not likely to face a shortage, said Jody Pollok, executive director of the Corn Marketing Program of Michigan.

More than half of all corn produced annually in Michigan is exported and 10 percent is put into residual storage. If demand increased substantially, farmers of other crops would likely switch to corn, she said.

Although corn prices are rising, burning kernels still offers substantial savings over other fuels. Over the past five years, for example, the price of propane has increased 63.8 percent in the state, according to the Michigan Public Service Commission.

"Our customers say it's the cheapest source of heat and they like not being dependent on oil companies or the utility," Grishkevich said.

And while corn may cost less than other fuels to produce the same amount of heat, it doesn't mean it's a wise option for everyone, said Larry Kaufman, energy efficiency expert at DTE Energy Co.

"If you're in a city area it maybe difficult to buy the corn and have a place to store and dry it," he said. "If you're in the country, I think it's a great idea. Michigan is an agricultural state … Why use oil from overseas when we can supply (corn) here?"

Corn has been the perfect fit for the LaLondes, who buy it by the trailer load three or four times a season from a local cooperative.

The couple began seeking alternative heating fuels after the shock of propane prices. They tried wood pellets, but the LaLondes found that corn was more widely available. They use three corn stoves to heat their Raisinville Township home and garage.

So certain is Lalonde, an electrician, of the value of corns stoves, he's now a dealer. Last year he sold the 35 he could get and has already sold a dozen this year.