gasoline or propane.
Diesel has dominated the wood chipper market for decades, but the development of emission standards for new off-road diesel engines has forced the tree care industry to explore and develop equipment over the last few years that alternative fuels can power.
Gasoline has risen as the top alternative. Chipper manufacturers have unveiled gas-powered options in the 12-, 15- and 18-in. classes, and a number of tree care service providers have taken to these.
“Before emission regulations were in place, 98 percent of all chippers were on diesel,” says Casey Gross, a tree care product sales manager at Morbark. “Now, with the new emission standards and the new tier of engines, 25 to 30 percent are leaning toward gas engines. The Tier 4 emissions regulations are driving the change and driving customers to look at alternatives.”
Specifically, costs are the primary driver of the shift away from diesel in certain chipper classes, says J.R. Bowling, vice president at Rayco Manufacturing. The cost of a Tier 4 Final diesel engine in the 75 to 173-hp range is prohibitive compared with a gas engine in the same class, he says. Plus, the cost of gas in recent months has been particularly rewarding for those with gas-powered equipment.
“If a [tree care service provider] is paying on-road diesel prices, those have been higher than gasoline for some time now,” Bowling says.
Still, gas isn’t a perfect solution. Some tree care service providers may prefer diesel engines in the 75 to 173-hp range because they deliver a higher torque than a gas engine, Bowling says. Yet, gas competes with diesel in this range.
“Customers find that a gasoline-powered engine can do a job that’s every bit as acceptable and save them a lot of money,” Bowling says.
Propane’s emergence
Gas isn’t the only alternative to diesel that has emerged. Propane also has a presence, and manufacturers like Bandit Industries, Morbark and Vermeer have dual-fuel models for tree care service providers who want them.
The tree care industry hasn’t fully wrapped its arms around propane yet, but a time may come when it does.
“Our industry just hasn’t made the leap,” says Brett Bartels, a Vermeer engineer. “[Propane] is a tool in the toolbox. It’s just a matter of whether they choose to use that tool or not.”
The Propane Education & Research Council (PERC), a check-off program that the propane industry operates and funds, has voiced its interest in pressing further into the tree care market with chippers. Propane’s current availability in the market is as a dual-fuel option through cylinders, but PERC is exploring opportunities for OEM propane engines that dispensers could fill.
“We’ve spent the last year really trying to find the engines worldwide that made sense,” says Tucker Perkins, PERC’s chief business development officer. “When we look for engines we’re looking for engines with the same operating characteristics of the diesel [engines] they’re replacing. These are highly efficient and have the same kind of durability profile of diesel.”
Propane is a natural fit for the tree care industry, Perkins argues.
“[Propane] has a really exciting story for tree care,” he says. “Tree care can take on anything from cutting down trees to doing good things with trees, but a lot of people tend to view cutting down trees as anti-green. If you migrate from gasoline or diesel to propane fuel, a couple things happen automatically: You reduce your carbon footprint and change your image because you can talk about reduced emissions.”
The complexities of Tier 4 diesel technology present a particular opportunity for alternative fuels like propane, Perkins adds.
frontier for alternative fuels?
“It’s hard to get diesel clean enough to burn properly in these Tier 4 engines,” he says. “ For diesel to better [its standing], there would have to be a radical change in the technology of the engine. That doesn’t appear to be happening. There’s complex filtration and complex equipment.”
Jay Sunderman, the strategic business unit manager of tree care/rental and landscape at Vermeer, sees potential for propane to gain momentum with chippers. Still, a number of details related to access must first be ironed out if tree care producers are to switch fuels.
“In regard to LP gas (propane), we’ve made our system so there are removable 33-lb. tanks that are typical to what’s mounted on a forklift truck,” Sunderman says. “It’s readily changeable, but you still need to have a source for the tanks and set up that distribution versus filling up at a pump. Some infrastructure needs to be put in place, and relationships need to be made between the user and propane supplier to make it viable.”
Morbark has had some interest in its dual-fuel 12- and 15-in. chippers, but Gross points out many of the same obstacles for propane as Sunderman.
“We’ve built a handful of propane chippers already because it’s really a slight modification to the engine itself, and we just have to install propane tanks and the lines to run to the engine,” he says. “The downfall to that is having the tanks available. You have to have multiple tanks to keep running long term. When you get out of a city, propane is not that readily available.”
If propane’s availability and access can be addressed, Morbark has shown that propane offers the lowest operating costs – at least for two Beever chippers the company compares across diesel, gasoline and propane.
Morbark compares the Beever M12R, which features either a 74-hp Tier 4 diesel engine or an 89-hp gasoline/LP gas engine. The company concludes that use of a diesel engine costs users $24.47 per hour to operate over 2,500 hours. Gasoline ($22.14 per hour) and LP gas ($21.28 per hour) are presented as less-expensive options.
Morbark takes the cost of diesel exhaust fluid (DEF) into account in its M12R comparison. The company estimates users will spend $735 on DEF for 2,500 hours of use.
Considering the cost savings available with lower-horsepower models, PERC is exploring other propane engine opportunities.
“We’re taking a fresh look at where any diesel or gasoline engine is in place,” Perkins says. “A propane-fueled engine probably has market opportunity anywhere an engine is consuming diesel fuel or gasoline.”
In addition to propane, electricity may soon carve out a space with tree care equipment.
“You’re going to see more manufacturers looking at alternatives such as electric,” Gross says. “You’re seeing more electric cars and charging stations. We’re actively pursuing the electric market right now.”