Corn for heat still competes
An Iowa State University (ISU) test done in 2006 showed that burning corn in a modest-size corn stove generated a savings of nearly $4 a day. While much has changed since then, the cost of heating with a corn stove still matches propane with a corn price of $6 per bushel and a propane price of $1.80 per gallon.
For the original test, the heated area in the shop comprised 3,023 square feet with a ceiling 16 feet high. The area also included a loft over the office. This additional area was nearly 1,100 square feet and had a ceiling 7 feet in height.
The shop's main heat source was a propane furnace with an output of 200,000 Btu's. The furnace fan had no supplemental forced-air distribution system.
The corn stove used to provide supplemental heat was a Baby Countryside model rated at 40,000 Btu's. “The stove was located along the east wall of the shop, at the midpoint of the building,” says Josh Sievers, ISU agricultural specialist. “The stove had a blower built into it, and we did not supplement any air movement with the stove.”
To gather energy-use information for each of the heat sources, testers heated the shop solely with propane for two days and used the corn burner to heat the shop the following two days. Target temperature was 60°F.
When the furnace was the sole source of heat, propane use averaged 6.9 gallons a day. Propane use while the corn stove was operating averaged 2.3 gallons a day.
Average daily use of corn was 1.3 bushels, or 75 pounds. One bushel of No. 2 corn provided 292,000 Btu's, while 1 gallon of propane provided 92,000 Btu's.
Besides offering benefits in energy savings, the corn stove had a reasonable purchase price and offered easy installation. While the stove used in the test was donated, similar models were priced at $1,200 during the time of the trial.
Given the potential for an increasing price of propane, the cost-effectiveness of burning corn then increases. “If propane nears $2 a gallon, you could pay $7 a bushel for corn to achieve a similar heating value,” says Sievers.
Looking To The Future
With the price of corn going up this year, Jim Calloway says sales of corn burning stoves at Amaizablaze Corn Stoves by Nesco, Inc. have declined. “They are moving much slower than in years past,” says Calloway, a design engineer at Nesco. “The years 2003 to 2006 were really good.”
The company moved into a larger facility and at one point was making 100 stoves per day. Production has slowed since.
“A lot of it has to do with other fuel prices,” says Calloway.
His prediction is that other fuel prices will go up, and corn will remain where it is or drop. “It depends on if the government decides to get out of using food stock for ethanol and gasoline,” Calloway says. “If they quit using corn for ethanol and use biomass materials such as switchgrass or other nonessential plant by-products, prices should go down.”