Biomass: No Chip Left Behind

In early February, Wisconsin Governor Jim Doyle announced that a biomass boiler would be installed in a heating plant located on the Wisconsin capital city's isthmus. Throughout the state, biomass is attracting a considerable amount of interest as a fuel for power generation in factories and power plants.

Madison's new boiler will replace a coal unit and be capable of burning up to 100% biomass, eventually using as much as 250,000 tons per year. In announcing the change, Governor Doyle said it will help create and sustain a biomass market in Wisconsin and provide economic benefit for landowners, farmers and processors in the state.

The potential for biomass as a renewable fuel isn't limited to Wisconsin. Brett Hulsey, president of Better Environmental Solutions, a Wisconsin-based environment and energy consulting firm, wrote that the estimated 231 million tons of potential biomass available in 12 Midwestern states could make the region America's "biomass Saudi Arabia."

How all of that biomass — which is anything from corn stover to switch grass to forestry residue — will be harvested and transported efficiently is a challenge teams of farmers, researchers and engineers are working to solve.

For the forestry industry, woody biomass makes sense. In the woods, a biomass harvest typically involves converting what was a wasted by-product of logging — it was either burned or left to rot in situ — into a valuable commodity. In areas hit by insect infestations or wind damage, proper timber management means harvesting the downed timber before it ignites.

"Woody biomass can include tops and branches, dedicated tree crops and underbrush. It's also industry residue, such as from pallet and window factories," says Don Peterson, director, Sustainable Resources Development, Crystal Falls, MI. "Many land owners want a park-like environment after a logging operation has moved out. The logger often doesn't pay for the residue but needs to dispose of it, so it could be another income source."

One of the biggest limitations to biomass production is transportation costs, and the problem becomes more difficult as customers increase their appetite for wood. "Biomass is totally different than traditional fuels," says Hannu Kivela, director for strategy and customer cooperation, Ponsse Oyj, Vierema, Finland. "The more you require wood energy, the more it will cost, because it means greater transport distances. Weight can fluctuate, too, depending on season, species and size of material."

Ponsse's North American operation in Rhinelander, WI, has been drawing on its parent company's expertise with biomass harvesting, in which it has been working since the late '90s.

"There are costs when it comes to handling forest residue and getting it roadside," says Ponsse's Stacy Wagler, part of the technical support and product development team working to make biomass profitable. It is working with contractors who are already selling woody biomass.

Ponsse's strategy is to first look for ways to modify existing equipment in order to keep the cost down for end-users. By providing attachments for Ponsse harvesters and forwarders already in the fleet, loggers may be able to cost effectively harvest biomass. "If we can get costs down to efficiently do this, contractors could start make money. We need to look at the return on investment," says Wagler.

Maximizing machine usage is key. Ponsse's 275 hp Dual Harwarder (a harvester and forwarder in one machine) can also be equipped with a Ponsse-designed EH25 multipurpose harvester head on a 30-ft. boom to cut multiple trees simultaneaously up to 8 in. dia. and collect them in bunches, all while parked in one place. Its H53 harvester head can also be fitted for "multi-stemming."

Ponsse's Biomass Transport System (BTS), which resembles an animal's rib cage when installed on a forwarder, uses hydraulics to open and close, compressing the logging residue for its trip out of the woods. "To get the biomass out of the forest we have to look at load size, says Kivela. "You can't a get a full load of residue on a standard forwarder, because it takes up so much space."