Does it make sense to use poultry litter as fuel?

One of the disadvantages of industrial-scale use of poultry litter as a fuel is the high cost of hauling litter off the farm, because litter is high in moisture and isn't as energy dense as coal. Excel Energy plans to buy the Fibrominn 55-megawatt poultry litter-burning power plant in Benson, Minnesota, and shut it down. The plant has been in operation for 10 years and it is still the only one of its kind in the U.S. I have lost track of the number of other similar projects that have been proposed in just about every major poultry growing area of the country that were never developed.The bottom line is that other forms of alternative energy, like wind, can generate electricity for a fraction of the cost of operating a large-scale litter-burning plant. But what about on-farm use of poultry litter as a fuel? Global Re-Fuel is a start-up company that is betting that on-farm furnaces for heating poultry houses with poultry litter will prove to be an economical alternative for growers. The 500,000-British-thermal-unit-per-hour furnace that the company has developed is being marketed for $100,000. One furnace should be able to heat two poultry houses.Burning poultry litter on-farm eliminates the hauling cost issues faced when litter is aggregated from multiple farms to serve an industrial user. Unlike industrial-scale facilities, poultry farms have had to rely on propane as the primary fuel to heat houses. Propane is not as economical a fuel as are coal and natural gas.I have covered several biomass-burning furnaces for poultry houses over the years. Furnaces have been designed to burn everything from poultry litter to hay to corn to heat poultry houses. One drawback of these systems has been that they require more attention than do propane powered systems, because feeding the fuel into the furnace requires human intervention. With propane, the grower just has to monitor the amount of fuel left in the tank and remember to order more.Biomass furnaces, including ones that burn poultry litter, are located outside the poultry house and exhaust outside the poultry house. Combustion inside the poultry house, as is the case with propane heaters, introduces carbon dioxide and water vapor into the air of the house. Research has shown that bird performance is improved when external furnaces are used because the ammonia level in the house is reduced, litter moisture is lower and ventilation rates in the house can also be reduced.