January 21, 2006 Corn Stoves For Home Heat Are Hot On US Market
All of the corn stove makers are sold out with long waiting times and sales volumes have more than doubled in the last year to about 150,000 stoves a year according to one report. Why the big demand for corn heating? Corn is a much cheaper source of heat than wood, natural gas, oil, or propane.
Why all the sudden hullabaloo? Simple – nothing costs less to burn at this point than corn, which sells for about $2 per bushel. According to figures provided by Even Temp, maker of the St. Croix line of stoves, the cost per therm for 100,000 British thermal units is 42 cents. The same per therm cost for natural gas is $1.40 and $2.60 for propane (LP). Wood is 64 cents per therm.
And Dennis Buffington, a professor of engineering at Penn State University, provided these figures in a recent Wall Street Journal story about corn stoves: For 1 million BTUs of heat, it takes $16.47 in natural gas, $33.80 in propane and a mere $8.75 for corn.
Check out Buffington's neat web site on corn as a heat energy source.
Corn heat costs about the same as coal heat but with far less pollution. (same article here)
It would cost about $130 worth of corn to heat a 2,000-square-foot home in Colorado for a month during the winter with a corn-burning stove, according to figures provided by Dennis Buffington, a professor at Penn State University who has studied corn-burning stoves for seven years.
In comparison, it would cost about $125 a month using a coal stove and $247 for natural gas.
Corn stove sales might rise by a factor of 5 from 2004 to 2006.
About 65,000 corn stoves were sold domestically last year, estimated Mike Haefner, president of Minnesota-based American Energy Systems. He expects a jump to about 150,000 this year, and at least 350,000 in 2006. Even with a retail price of $1,600 to $3,000, the stoves often pay for themselves within a year or two.
Unless you have a really cheap source of wood (e.g. your own forest) corn seems a better choice. Wood pellets are in short supply and wood pellet prices have more than doubled.
Retailers, meanwhile, have been struggling to find any pellets for sale. But those that have a supply should ration their sale to no more than 10, 50 or 40-pound bags per customer, the CPB is recommending. The cost per bag has risen from $3 to between $7 and $10.
The demand for pellet stoves increased dramatically following the severe price increases forecast this winter for natural gas, heating oil and propane.
You can burn corn in some wood stoves. But corn leaves behind a sugary residue which is difficult to clean from wood stoves.
When corn is burned it leaves behind a substance from the sugars it contains that when cooled is very hard and stays in the burner. These clinkers, as they are called, must be regularly cleaned out of the stove. Some special corn stoves are designed to automatically clear clinkers, Koval said.
Shelled corn contains about 7000 Btu (British thermal units) per pound at 15 percent moisture, or about 392,000 Btu per 56-pound bushel. That rating is about the same for wood pellets.
Actually, Dennis Buffington says corn has 6,800 BTUs per pound and wood 8,200 BTUs per lb. So for heating wood is worth about 20% more per pound than corn.
There are hassles to operating a corn burning stove.
Yet owning one of these stoves is not like owning a gas furnace, Doubek said. "You've got to be a handy person to own a pellet stove."
The fire pot must be emptied daily, the ash tray about once a week. There's dealing with the 40-pound bags of pellets or corn to keep the fuel bin full, and the stove requires an annual disassembly and cleaning of the heat exchanger, combustion fan, and other parts exposed to sooty smoke.
With better designs that hassle factor looks reducible. Big feeder bins could reduce the frequency of refueling to once a seaon. Also, the waste ought to automatically get moved into a fairly large sized container that could get taken out a lot less often.
Mary-Sue Halliburton, in an excellent survey of corn stoves, points out that if corn stoves were upgraded to do co-generation of electricity they could power their own fans and also run household appliances. I agree with her that there's still plenty of room for innovation to make corn stoves better values.
How about making a corn hot water heater also produce steam for a small electric turbine? Corn hot water heaters already exist. Here's a corn boiler water heater that comes with a 14 bushel storage bin to reduce the frequency of reloads.
Local costs of corn vary quite a bit by region but for some corn is incredibly cheap.
"It's beautiful," exclaims Mr. Hallman, a retired mailman. He went on the warpath in 2000, turning off his gas furnace after paying a $400 monthly heating bill. After that, he struggled to heat his house with a wood stove. "I had to bring in wheelbarrows full (wood), clean out ashes, soot and creosote," he recalls. "Those days are over. This burns absolutely clean."
Corn warmth also comes cheap. Mr. Hallman pays an area farmer $1.60 a bushel to fill the back of his pickup truck with dried kernel corn. He unloads it into a plywood bin in his garage. Every morning he pours a couple of pails into a hopper on top of his furnace, which burns a little less than a bushel a day. He figures his new monthly heating bill will be less than $60.
To put that $1.60 per bushel in perspective consider that 1 gallon of #2 fuel oil has about the same amount of heat as 22 lb of corn. But there are 56 lbs in a bushel of corn. 56/22 is equivalent to 2.55 gallons of fuel oil per bushel. Of course, the fuel oil is going to cost you over $2 per gallon and possibly a lot more (as of this writing oil prices are headed up near $70 per barrel). So the oil equivalent is probably $5 or $6 or about 3 or 4 times more expensive. If you can get corn for $1.60 per bushel you are getting a great heat energy deal.
Seeing how cheap corn is as a heating source I've been wondering why utilities aren't trying to use it to generate electricity. So I did some poking around and came up with one utility that is attempting to use corn stalks and other biomass to generate electricity. Cedar Falls Utilities of Iowa is experimenting with corn stalks and other biomass to run an old coal electric generator.
CEDAR FALLS, Iowa -- Chunks of coal lay on the fringes of a 450-ton mountain of cubed biomass -- a symbol of transition as this eastern Iowa city enters a new age of electricity.
The cell phone-sized cubes -- comprised of corn stalks, switchgrass and oat hulls -- are crammed into a pole building and will be burned next month to show whether biomass can partially replace coal as a source for Cedar Falls' power.
If successful, Cedar Falls Utilities plans to convert one of its two coal-fired generators into a biomass facility, providing nearly a quarter of the city's electricity through environment-friendly means.
They are experimenting with a 16 megawatt steam turbine which they burn coal in for peak loads.
CFU has burned small quantities of biomass in recent months, said CFU Engineering Projects Manager David Rusley. "We needed to run a more extended test burn to move the project forward," he said. "The difficulty has been finding sufficient quantity of biomass in a form we can use in our boiler. After looking at many alternatives, we decided to manufacture the fuel we need."
Ultimately, the Utility's goal is to fuel one of its local generating units exclusively with biomass. Known as Streeter No. 6, the unit is a 16 megawatt (MW) steam turbine, powered by a boiler that typically burns stoker coal (small chunks of coal up to 1.25" in diameter).
"If we can convert Streeter No. 6 to biomass, nearly a quarter of the electric load in Cedar Falls could be met with biofuels grown in Iowa," said CFU General Manager Jim Krieg.
CFU is motivated to experiment with this old coal burner because new emissions regulations require an expensive upgrade if they are to continue burning coal and that upgrade is not cost effective. CFU thinks they can burn corn cob pellets with no major changes and eliminate the need for coal emissions reduction equipment.
CFU found it could burn the corn cob pellets without any major changes, only adjusting the oxygen composition in the stoker.
The biomass testing not only serves as a way to further CFU's endeavors into renewable fuels, but it could give Unit 6 new life. Federal emission standards will require $1.6 million in environmental upgrades.
"We can't justify that investment if we are only using the unit a few days each year to burn coal," said CFU General Manager Jim Krieg. "If we can burn a biomass fuel, we'd like to turn it into a base load unit that operates continuously."
I commend the Cedar Falls Utilities board of directors for their attitude about costs.
"The board's goal is to get to 10 percent renewable energy in Cedar Falls, but they want to do it without raising costs to customers," Zeman said.
Alliant Energy looks like it might also try to generate electricity from biomass.
The test comes as more utilities are exploring fossil fuel alternatives. Alliant Energy is also a partner with Chariton Valley Resource Conservation and Development and the U.S. Department of Energy on a biomass project in Chillicothe, near Ottumwa.
Corn for heat sure looks like a comer on the energy scene. While the US government has served Archer Daniels Midlands and the farm lobby by funding dubious corn ethanol production a far more cost effective use of corn for heating is taking off with little government intervention. I suspect there's a lesson in that.
By Randall Parker at 2006 January 21 08:03 PM Policy Energy | TrackBack
