

Still, you don’t have to be stuck with a huge bill once your grain is dried to a desired level. Through sound purchasing decisions, you can slice fuel costs. Here’s how.

The natural way. You may need to purchase little or no extra equipment. For example, natural air drying can cut drying costs with a sparse investment, says Bill Wilcke, University of Minnesota extension agricultural engineer. This method uses bins with full-perforated drying floors and fairly large fans. Fan size runs approximately .75 to 1.0 hp/1,000 bu. of corn for bins that are no deeper than approximately 18 ft.



“As farms get bigger, the key is not just energy efficiency,” reminds Charles Sukup, president of Sukup Manufacturing, Sheffield, IA. “It’s a combination of efficiency plus speed and what you sacrifice in yield losses by not getting the crop out on time. That’s where a stand-alone dryer and speed become important.”

Don’t overdry. That’s why companies still focus on speedy, high-temperature drying systems. “There probably isn’t any dryer company designing a new dryer model based solely upon energy efficiency,” says Warren Odekirk, sales and technical support manager for Growmark, Bloomington, IL.



Thus, some firms have engineered driers to more uniformly dry the grain column inside the dryer. “This makes dryers use less energy,” Odekirk says.



Some companies design dryers to reuse heat from the drying and cooling of grain. Beard Industries, Frankfort, IN, claims that its Superb Energy Miser dryer cuts the fuel costs of conventional dryers by 50%. That’s because the firm’s dryer reycles exhaust through the system.

Beard Industries is researching more ways to improve energy efficiency, says company president Bill Beard. “But for now, the cost of fuel isn’t high enough to make more changes economically feasible,” he says.



If a farmer overdries grain by one to two moisture points, most computerized drying controllers can pay for themselves in one to two years, Odekirk says. Here’s a two-step example Odekirk uses to calculate payback:

  1. Determine overdrying costs.


  2. Calculate energy savings.


Solar surge






Biomass boom?

During the energy-sparse days of the late ’70s and early ’80s, researchers studied biomass fuels such as wood, hay and crop residues to dry corn.

Biomass fuels showed potential because they were renewable and energy dense. Scientists believed that biomass fuels might help stabilize fluctuating external energy prices and even enable farmers to sell fuel. However, energy prices stabilized and research funds evaporated before biomass drying systems became operational.

Now rising energy prices are once again sparking interest in biomass fuels.

Bill Wilcke, a University of Minnesota extension agricultural engineer, says that, if you are considering using biomass fuels to dry corn, you should first answer these questions:

  • Can you harvest biomass ahead of corn harvest, or will it consume time and labor best spent to harvest corn?

  • What’s the biomass fuel’s expected moisture content? Will you need to dry biomass before you burn it? Remember that the higher the fuel moisture content, the lower the net energy production per wet pound of fuel.

  • Do you need special equipment and facilities to harvest, transport and store the biomass fuel? Or can you adapt equipment and facilities that you already own? If you have to buy special equipment, don't forget to include the cost of that equipment in your cost per British thermal unit (Btu) calculations.

  • Is the fuel difficult to use? Does the fuel flow on its own and can the fuel supply system be automated? Or will it consume considerable labor to supply the burner with fuel?

  • It may be easy to build an automatic fuel supply system for a fuel in pellet or granular form, but it would be more difficult to establish an automatic system that consumes logs or large bales.

  • Can you buy a burner that burns your biomass and will it supply the required number of Btus per hour? Several companies produce small biomass burners, but few firms produce the larger sizes needed for heated-air corn dryers.

  • If you decide to build your own burner, remember that it can be difficult to develop a design that provides optimum air amounts for complete combustion, is easy to feed, can withstand high temperatures for long periods of time and conveniently removes ash, clinkers or slag.

  • Will biomass removal reduce soil quality and increase erosion potential? For example, using all the cobs from a crop of corn may not boost soil erosion. However, removing all corn stalks may significantly raise soil erosion.

  • Is there a positive net energy balance for using biomass fuel? How much do you gain after you subtract energy required to grow, harvest and transport the biomass fuel from the energy produced by burning biomass?

  • Is the biomass more valuable as food, feed or an industrial feed stock than it is as a heating fuel?

  • Is use of the biomass fuel cost-effective? When you consider the costs for equipment, labor and other inputs for producing, harvesting, transporting, storing and burning the biomass product, is the cost per Btu competitive with other alternatives?

For more information on any of these topics, contact Wilcke at 612/625-8205 or send him an e-mail at wilck001@umn.edu.