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Economics

Burning corn and other biomass fuels generally compares favorably with fossils fuels.  This does not, however, take into consideration the additional costs of purchasing and installing the furnace – in most cases, these units function best as supplemental heaters rather than as a replacement for a traditional oil or gas furnace.  In addition, there are additional labor components that need to be taken into consideration when calculating the real cost of burning corn compared with oil or gas.

 

 

 

Table 1. Heating Fuel Cost Analysis

 

 

 

 

 

 

 

 

 

 

 

 

 

Fuel Source

BTU's /unit

Units/Million BTU

Fuel Price/ unit

Cost per Million

Efficiency

total cost/ million BTU's

 

Shell Corn

8500

lb*

117.65

$0.10

$11.76

75.00%

$15.69

 

Electricity

3413

KWH**

293.00

$0.12

$34.40

100.00%

$34.40

 

Fuel Oil

139000

gal***

7.19

$2.85

$20.50

85.00%

$24.11

 

LP Gas

91690

gal***

10.91

$2.33

$25.41

85.00%

$29.90

 

Wood Chips

4600

lb*

217.39

varies*****

varies

70.00%

no estimate

 

Hardwood Pellets 

9000

lb****

111.11

$0.12

$13.83

87.00%

$15.90

 

 

 

 

 

 

 

 

 

 

*Costs analysis is based on price of $200/ton. BTU/lb is based on corn dried to 13% moisture content. 

 

 

 

**price: WEMCO small business flat rate as of October 24, 2007, BTU data from J. Bartok, Univ. of Conn Extension.

 

 

***Oil and LB prices:Whitings Energy Fuels, Amherst, as of October 24, 2007;BTU data from J. Bartok, Univ. of Conn Extension.

 

*****Wood pellet price:Amherst Farmer  Supply, October 24, 2007; pellet company guarantees at least 9K BTU/lb

 

 

*****Wood chip sources vary: some are free, others have variable prices; quality is not consistent. 

 

 

 

The economics of burning corn can be further improved if the grower is interested in growing their own corn.  An acre of corn grown for grain will produce roughly 140 bushels of corn, which in turn will generate roughly 55-65MBTU. Yield will vary greatly with variety, management, and the quality of the land.  There may be substantial benefits from producing the greenhouse fuel internally, but there are many factors involved in the process that do not necessarily have a visible dollar amount. For instance, both time and land usage required may not only incur a real tangible cost, but also have costs associated with the opportunity that the grower is forgoing in exchange for the opportunity to grow their own fuel.  While some farms may have unused land that can be used to grow corn without giving up opportunity, most growers have a finite amount of available crop land, and giving up vegetable acreage to grow fuel corn can have real cost in terms of reduced overall yield.  Some of this cost is mitigated by the benefits of using corn as a rotation crop for vegetables.  To consider all possible alternatives and their values would be a vast study in itself. Therefore, this analysis will focus on detailing the savings of growing corn internally for fuel and provide a general idea of how much alternatives to growing corn need to be worth per acre to decide to purchase fuel from an external source.

In addition, the estimated payback time presented in the individual case studies assumes that the corn furnace is being used in conjunction with an existing oil or propane heater.  We do not currently recommend relying entirely on the use of a corn furnace, so the estimated savings is based purely on differences in fuel costs for the same amount of heat.  If you were installing a corn furnace instead of an oil furnace, the payback time would be further reduced by the price of the oil or propane heater relative to the corn furnace.