As supplies of coal, oil and gas continue to dwindle, generator manufacturers are planning for the day we run out. They are investigating alternative, renewable fuels that can power on-site generators traditionally powered by natural gas, propane and diesel fuel.

Manufacturers say most of these technologies are still years away from being viable alternatives on farms. The holdup on most of these is cost. “All of these things cost more money than it does to hook up to an electrical power line, so that is why you don't see a big rush for it,” says Greg McFarland, marketing manager with Federated Rural Electric in Jackson, MN. However, cost may come down as more products are marketed and mass produced.

Here is a look at the alternative energies that may soon be viable for Midwest farms.

Wind

Wind turbines that generate electricity are here now. And although they are still expensive, their cost is coming down, approaching that of electricity. New wind systems 39 kW or less (enough to power a typical farm) cost between $100,000 and $115,000, according to McFarland. To reduce that initial capital cost, farmers can buy retired or reconditioned windmills for $45,000 to $60,000, he says.

Another limitation of wind is that it does not blow all of the time. “Because wind is unpredictable, it can't be used as a reliable backup, but can be used as a second or third cash crop if installed correctly,” McFarland says. Also, you need to be in a windy location, such as on a hill. For every 10 ft. of height over 80 ft. on the tower, you will pick up another 1.5% in efficiency, he says.

Most of the wind turbines used today are installed to generate electricity for the grid, not as an on-site source of backup power.

Visit the Web site of American Wind Energy Association (www.awea.org) for a listing of wind turbine manufacturers.

Solar

The cost of solar energy is coming down, but it is a niche market, according to John Holt, manager of generation and fuels at the National Rural Electric Cooperative Association (NRECA). “It is a lot more expensive than traditional electricity unless you are far from the grid and need power for a well to pump water for cattle or for a residence,” he says.

What's more, some areas of the Midwest may get only six hours of peak sunlight in which to charge a battery, which in turn will allow you to have power to operate some small motors or lights, according to Federated's McFarland.

“With solar you can preheat or heat some or all of your hot water needs with the right equipment,” he says. “It may be a good second solution in areas like Montana, the western Dakotas and Colorado where there are long distances between lines and where a line extension would be cost prohibitive.”

Biomass

NRECA's Holt says changing biomass to usable energy is doable, but high priced. “There are a few farms that are using cow manure to produce methane and using it for either heating or for electricity,” Holt says. “So technically, it is available, just not economical.” He rates its viability as equal to that of solar energy.

Microturbines

Microturbines, which operate like a jet engine and are about the size of a refrigerator, are reliable, affordable and available now. But they are still in the early stages of commercial use.

They are capable of producing large amounts of power. However, one of their biggest drawbacks is that they are inefficient unless you can find an application for the exhaust heat, Holt says.

Fuel cells

Of all of these technologies, Holt rates fuel cells as the most viable alternative in the future. And the future could be very close. “A number of manufacturers are putting out their beta models and hoping to put out commercial units next year,” he says.

They offer the potential of being efficient, quiet and reliable. And the byproduct emission is just heat, which can be used to heat water.

“A number of farms have these test units right now,” Holt says. “Cost is high, but the hope is by going to mass production, it will bring that down to an affordable cost and offer superb opportunities.” He predicts that farmers will be able to buy them in about three years.