For almost all of human history, from the cavemen to just a century ago in this country, wood was the primary source of energy, depended on for cooking and heat. In many places, that remains the case today. So, how has it come to pass that we sometimes see wood as a waste product, something we’re desperate to get rid of?

Most tree care companies look for use for the “wood waste” they generate, selling it as mulch or firewood or giving away the raw chips. Others, though, continue to haul it to the landfill. Some have found that the cavemen had it right – there’s real power in wood. These tree care professionals service the biomass energy market, with the wood chips being used to generate electricity. Some who have experience selling wood chips into the biomass energy market are finding success; others advise proceeding with caution. In large part, this is because the biomass energy is strong in certain areas, but more tenuous in others.

Joe Benigno’s Tree Service, which operates in California and Nevada, sold wood chips to electrical generating plants for several years, but stopped late last year when some plants in his area stopped taking chips and others dramatically lowered the pay scales. “The prices are so pitiful right now, it doesn’t make sense for us to truck them that far,” owner Joe Benigno explains.

For the past few years, Arborwell has been selling wood chips to co-generation plants that burn the wood to produce electricity through steam-driven turbines. Photo: Arborwell

He first sold chips for biomass energy a little over two years ago when a plant opened up just 15 miles away. At that time, the biomass market was “super hot,” recalls Benigno. “I geared up to be a supplier for them, and we purchased a big CBI horizontal whole-tree chipper. We even brought in that chipper to their yard and did some chipping for them when they received saw logs,” he says. “We would accumulate our own biomass from local operations, wait until we got a decent amount, turn them over with a loader to help dry the chips, and then deliver them there. If we had trucks operating right near the plant, we would even send them directly there to dump 15 or 20 yards at a time, but in less than a year, that plant had closed.”

Benigno’s Tree Service has hauled wood chips to several other power plants. In some cases they were not paid for the chips, but the plants provided a convenient and environmentally sound way to dispose of them. In other cases they were paid a small amount. “It’s all supply and demand,” says Benigno. He was preparing to enroll in the BCAP (Biomass Crop Assistance Program), which at the time paid a subsidy per bone-dry ton. “That would have made it more advantageous,” he says, but the program was curtailed before he could take part. “We’ve been hearing that program is really going to be getting started again, but nobody knows for sure,” Benigno adds.

He has hauled wood chips to power plants up to 150 miles away, but now he’s waiting for biomass prices to go up again before resuming that practice. To make a five-hour trucking loop make sense, the price has to be right and the chips as dry as possible, “so you’re not trucking water,” Benigno explains. In the meantime, he’s found that providing wood chips to the erosion control market is making more financial sense. “We pretty much just charge for delivery and that lets us get rid of the chips. In other cases we stockpile them in our yard. We just had one customer who purchased 1,700 yards; all we had to do was load them and they provided the trucking,” he says.

Benigno feels that the biomass energy market will be cyclical; it’s down in his area at this time, but will likely come back. The power plants liked the chips he provided, whether they were from the whole-tree chipper or his fleet of Vermeer tow-behinds. “The spec is usually a 2 to 3 inch minus, and the nice thing about everything we take them from the tow-behind chippers is that it’s been processed at the curbside, so there’s no dirt or rock contamination,” Benigno notes. He’s following the biomass energy market to see when it might make sense to get back into it. “If there’s a plant that’s closer and the pay went up, it’s definitely something we would consider.”

While exact specifications vary, most biomass energy markets require clean, uniform wood chips. Dirt, rocks or other inconsistencies can cause problems in the material handling systems at power plants. Photo: Arborwell

In Texas, Cedar Beetle Land Clearing tells a similar tale. The company had been sending chips to biomass energy plants, but the market for wood chips has recently dried up. “There’s a lot of talk and a lot of speculation, but the market is way down right now. In fact, I don’t know of anyone who is taking them. It kind of comes and goes, but to my knowledge no really solid market has been established in Texas yet,” explains Katy Yaklin.

While Cedar Beetle produces large volumes of wood chips, Yaklin says that many tree services companies have a difficult time meeting the needs of biomass energy producers. “The problem is that you have to have a large, large quantity and a steady supply. If you don’t, they won’t purchase them,” she says. In that area, plants were looking for a supply of at least 30,000 pounds a month in order to sign a contract, she adds. Then there’s the additional chipping and screening equipment that needs to be purchased in order to meet plant specs. “We’re keeping an eye on the market, but we’re moving away from it because it’s just so volatile right now,” says Yaklin

There are places, though, where the biomass energy market for wood chips is strong. For the last five years, Arborwell, a tree care company with seven locations throughout California, has been selling wood chips to co-generation plants that burn the wood to produce electricity through steam-driven turbines. “We’re probably one of the only tree care companies that do business with them, because they need very, very clean, uniform chips,” explains Arborwell President Peter Sortwell. “If they get rakings of little branches [mixed in with the chips], it messes up their conveyor belt system.”

For that reason, there is a cost to being able to service this market. For example, chipper maintenance becomes a critical concern. “We have 60 chippers out there, and we have to make sure they are always very sharp and that the bedknives are absolutely perfect so the chip is very consistent,” says Sortwell. You also have to continually remind employees not to put any rakings or dirt or trash into the chip trucks, because that could cause the co-generation plants to refuse the entire load. Arborwell also had to invest in several large, pre-owned Caterpillar front-end loaders with specialized Tink buckets that tip from the front and can dump chips into tall trucks for delivery to the power plants. “We put a lot of money into this, because it helps us save a lot of money,” says Sortwell.

Before Arborwell began selling the chips for biomass energy, the company struggled to manage its wood waste. He says, “It’s always cost a fortune to get rid of chips. If you can’t find a place to recycle them or drop them in someone’s yard, you’ve got to take them to the dump and then there’s the drive time for that.”

Now the company’s trucks simply bring chips from the field back to the yards, where they are temporarily stored in large bins. Power plants pay based on the dry ton, so the goal is to dry the chips as much as possible prior to delivery. Arborwell then contracts with trucking companies that can deliver up to 100 yards of chips at a time to the co-generation plants. “We sell the chips to the power company and pay the trucking company and we still end up making a small profit on it. It’s almost a wash now, but as these plants become more popular they’re looking for more and more wood waste, so the price we get paid per dry ton is going up a little bit,” says Sortwell.

A similar success story can be found at Michigan State University, where a team of seven full-time arborists cares for the school’s roughly 2,000-acre campus. Beginning in 2010, all the wood debris generated from tree removal and trimming operations has been sent to the school’s on-site T.B. Simon Power Plant, one of the 500 largest power stations in the country. The multi-fuel plant runs mainly on coal, but also burns a sizable amount of biofuel, says Paul Swartz, MSU’s arborist supervisor. “We’re burning about 50 tons per day right now,” he notes.

The MSU arborists use a tow-behind chipper to process some wood immediately, but most branches and trees are brought to a site adjacent to the power plant. A large Morbark tub grinder is brought in three or four times a year to chip the wood. Swartz says that the chips produced by the tow-behind chipper would sometimes be too “stringy” for the power plant to handle, so those chips are now placed in the pile to be re-chipped by the tub grinder. “This ensures that the chips are all uniform,” he explains. Once chipped, loaders are used to dump the wood onto the coal piles and the two fuel sources are mixed together.

Wood chips trucked in from MSU’s Kellogg research forest are added to the pile. Landscape gardening crews at Michigan State also direct all brush and woody debris to that pile, which also includes lumber from pallets and other lumber generated from schoolwide operations. “We used to have to just landfill a lot of this stuff, and this is nice because it saves us thousands of dollars per year in landfill costs,” says Swartz.

Before the wood chips were sent to the power plant, most were chipped and made their way back onto campus as landscape mulch. “Now we get paid per ton for all of the wood we deliver to the plant,” says Swartz. A portion of those fees are used to purchase mulch from outside suppliers, which he says is a little higher quality than the MSU landscape services team was able to produce on its own. “Plus, we used to just put down so much mulch because we had it, now we’re a little more conservative about how much mulch we use, which is a good thing,” he adds.

Having a built-in market for wood chips courtesy of the on-campus power plant is proving to be a best-case scenario for getting rid of wood waste in an efficient, environmentally sound manner. Swartz says, “We’re able to utilize this resource we have right here, so it definitely works out well for everyone.”