Farming Magazine - July, 2012


Wood Waste & Recycling Edition: Odds and Ends

Efficiency is everything when it comes to biomass by Patrick White

For loggers in the Northeast, biomass is an add-on - one small part of a larger equation used by some to help improve the overall bottom line. "The economics mean that things really revolve around saw logs markets. Biomass is a secondary area," says Eric Kingsley, vice president of Innovative Natural Resource Solutions ( in Maine, who has studied the issue for many years. "Nobody is going into the woods just to do biomass - no landowner and no logger."

Photo courtesy of the U.S. Forest Service

While biomass remains a secondary market, it's an area that more loggers are getting into. Especially in northern Vermont as well as most of New Hampshire and Maine, notes Kingsley, there are well-developed, long-standing markets for biomass. "Loggers in those areas with the right equipment can really serve those markets," he explains.

So, what is the right equipment for loggers looking to integrate biomass into their existing round-wood operation? "In short, you can do it just about any way, but the most-efficient way is with a mechanized operation that includes a combination of grapple skidders and feller-bunchers," explains Kingsley. "For someone really wanting to make biomass a meaningful part of their operation, that's the way to go."

With this combination of equipment, the feller-buncher would first go out to harvest and lay down bunches of trees. "A grapple skidder then goes out and backs up to the bundles of trees, which still have the tops on them, absent what comes off when the tree falls, which can be very significant," says Kingsley. "The skidder brings the trees out to the landing, and that's where all the decisions are made."

It's at that point that sawlogs are differentiated from pulpwood, with logs grouped into various piles by grade. During this process the tops and branches of both sawlogs and pulpwood/firewood are removed. While there is sometimes chain saw work involved on a cable skidder job, Kingsley says that most loggers use a slasher for this process. "A logger using a feller-buncher and grapple skidder will already have a slasher on the landing," he notes.

For those not currently selling biomass, most of the tops and branches are likely being brought back into the wood, either for aesthetic or habitat reasons or to help support machinery in soft areas. Even for those looking to sell biomass, some of the tops and branches removed by the slasher continue to be used to pad and add flotation to skid trails, explains Kingsley. "The amount of money you get from biomass is pretty small, while the ability to keep operating on a muddy day without causing a lot of damage is worth a lot more," he points out. "Nobody in this industry wants to damage soils."

Tops and branches not needed for these purposes are simply piled up on the landing for chipping. "Usually, the biggest physical pile on any biomass job is the biomass pile. That's because a lot of the pile is air - it's tops and branches," he says. Whatever isn't suitable for the sawlog or the pulpwood piles makes its way into the biomass pile: "Basically, biomass is anything that doesn't meet another spec," says Kingsley.

While the biomass pile represents the largest pile by volume on the landing, "it's also far and away the lowest value," Kingsley states. He's examined the volume and value figures for logging operations in New Hampshire and found that in one recent (typical) year, biomass represented 4 percent of the value to landowners (probably slightly higher for loggers) from all timber harvests in the state and 29 percent of the volume. Sawlogs, on the other hand, represented roughly the same volume (31 percent) but accounted for 90 percent of the value. Pulpwood and firewood represent the remainder of each category.

These are important facts to know, because a product like biomass that's difficult to handle and not very valuable requires an exacting approach to have any hopes of being profitable. For starters, the fewer pieces of equipment involved and the fewer times the biomass is handled, the better, Kingsley emphasizes.

For example, the same loader used for logs on the landing is typically also used to feed the biomass through a chipper, and chips are usually blown directly into a truck rather than into a pile that must then be loaded into a truck. "The trick with biomass, if you want to make any money at it, is to touch it as few times as possible," he says. "And use the least amount of diesel as possible. As a general rule of thumb, it costs about $4 per ton every time you touch biomass, and $4 a ton is probably more than your profit margin, so an extra touch can kill you."

For this reason, while biomass harvesting can be done by loggers using forwarders and a cut-to-length system, this approach is somewhat less efficient because it requires the forwarder to make extra round-trips. "In the woods you would have your processor that does your felling and actually cuts the logs to length. The tops, obviously, are taken off at that point," Kingsley states. For operational - landing management - reasons, the two are generally picked up separately. "The forwarder will come through and collect loads of logs. Then it will come back and grab loads of tops," he explains. Traditional cable skidders can also be used for biomass, but this approach is considerably less efficient even than using forwarders, he adds.

While not as efficient has a fellerbuncher/ grapple skidder combination, biomass logging can be done with a forwarder. Typically, the forwarder will make separate trips into the woods to collect logs and then tops, both of which are then piled on the landing.

While there are a few machines on the market designed specifically for collecting, and even bundling, biomass, Kingsley says the numbers don't add up. The machines are too expensive and the price of biomass currently too low for this approach to make sense. "To my knowledge, and I've been watching this for a while, there is no one in the country actually using one," he says. "They are out there and they are very cool, but there would have to be a fundamentally different pricing for biomass to make them work, which is what they see in Scandinavia and how they make it work there."

These specialized machines also tend to perform best in plantation settings or pure softwood stands, where tops and branches are more flexible, rather than the mixed stands seen in this part of the country, Kingsley adds. "As far as I know, nobody in the Northeast has ever really used one," he says.

One specialized piece of equipment that is necessary for biomass is a chipper on the landing. "There are a few mobile chipper [companies] that service some loggers, but generally the chipper is a piece of equipment that the logger would own," says Kingsley. For those truly interested in entering the biomass market, making the investment in that equipment usually makes the most sense, he says.

Different biomass buyers may require somewhat different chip sizes and dimensions, but fortunately most chippers are somewhat adjustable, says Kingsley. The most important consideration is to start with a high-quality, dependable chipper and then maintain it properly, he emphasizes.

Trucking is another consideration, and one that that be handled by the logger or contracted out. Transporting biomass requires a different type of truck than the stake bodies normally used by loggers. "Basically, you need a box to blow the chips into," says Kingsley. Beyond that, the type of truck required depends on the destination of the biomass. Larger biomass users, such as electricity generation facilities or paper mills that burn biomass often have truck tippers, which literally lift the truck upward to dump chips out the back.

Smaller biomass users, such as schools with wood chip heating plants, aren't likely to have truck tippers because of the massive cost of such systems, points out Kingsley, "so with those you need a live-floor or walking-floor truck." The trailers on these trucks have a movable floor system that allows the truck to unload itself similar to the way a conveyor belt moves items along a line.

For a logger looking at the purchase of a truck, live-floor trailers are more expensive because of the complex mechanical floor systems required. Trucks that will be used with a truck tipper system, on the other hand, tend to be "beaters," says Kingsley. "You're often taking an old box truck that nobody wants and using a saw to cut the tops of the back doors off so you'll have a place to blow in the chips. All you need is a box to hold the chips and, of course, go down the road legally," he adds.

Biomass may not be a fit for every logging job. Kingsley says that sometimes landowners do request that biomass be left in place in the forest, but adds that it's much more common for landowners, especially those with smaller woodlots near their homes, to ask that all biomass be removed for aesthetic reasons. "They want it to look like a park. To them, if it's their backyard, it is sort of like their park," he explains. "But there are also good reasons from soil health to wildlife habitat to leave some woody debris - both coarse and fine woody debris."

For those jobs where harvesting biomass makes sense, using the right mix of equipment is critical to making sure it can be done profitably.

Patrick White is a freelance writer based in Middlesex, Vt. Over the past 10 years, he has covered a wide range of agricultural operations around the Northeast. He is always on the lookout for unusual stories and cutting-edge installations.