Pros and cons of propane

Nothing gets landscape companies thinking about alternative fuels like high gas prices. Converting a mower fleet from gas to propane isn’t a simple flip of the switch though. While the fuel cost savings and other benefits of propane can yield a strong return, the investment in systems and training requires some careful planning.

For some landscape companies, propane has helped support a broader plan of being more environmentally friendly.

“Our biggest motivator is green technology, so the clean-burning aspect of propane is a driving factor for us,” says Dan Bitler, fleet manager at Sebert Landscaping in Bartlett, Ill. “There is also a big cost advantage. In mid-September, we were paying around $1.50 a gallon for our liquid propane.” At the same time, gasoline was nearly $4 per gallon in the Bartlett area.

Bitler has been with Sebert Landscaping for six years, although the company first began using propane mowers a decade ago.

Now more than 80% of Sebert’s mower fleet is powered by propane. “That number is growing as we replace old gas-powered machines with propane mowers,” Bitler adds.

Unscheduled engine maintenance has been another factor in Sebert Landscaping’s decision to lean more heavily into propane. While routine preventive maintenance has generally stayed the same, there has been a reduction in engine component failures.

“Since propane burns so much cleaner, we’ve seen a noticeable difference in carbon deposits,” Bitler says.

Potential downsides to watch for

Over in the Cleveland area, Schill Grounds Management has actually seen more engine-related issues since switching to propane.

“These engines run a lot hotter even though they’re burning the cleaner fuel,” says Jim Schill, vice president of Schill Grounds Management in North Ridgeville, Ohio. “We’ve ended up seeing more engine wear and tear. It really surprised me, but I blew more propane engines than I ever did with gasoline.”

Schill Grounds Management first started using propane mowers nine years ago. Like Sebert Landscaping, the motivating factor was to become more environmentally friendly. That definitely panned out, as did the secondary objective of reducing fuel costs. What Schill didn’t anticipate was a sporadic loss in productivity, something that has prompted the company to begin migrating back to gasoline.

“Our propane mowers ran into starting issues when it was colder out,” Schill says. “We also noticed a decrease in power, especially on hills and slopes, which resulted in reduced blade speed. Then our guys had to mow too slowly and sometimes had to double-cut. When you can’t go full production with your mowers in commercial maintenance, that’s a problem. It all comes down to hours and dollars.”

In the Chicago area, Bitler says Sebert Landscaping crews have also noticed some power loss, mainly in the early season when temperatures are cooler and fast-growing grass is thicker and wetter. But the impact on manhours and cut quality has been negligible. And once crews get over that early season hump, it is typically smooth sailing.

Down in Texas, Scott Tintera says the advantages of using propane have far outweighed the downsides. Tintera is the lead technician at Clean Scapes based in Austin. He has been with the company for 13 years. “Clean Scapes was using propane before I even got here,” Tintera says. Today the company powers its forklifts with liquid propane, while a fleet of 100 zero-turn mowers runs on vapor propane.

Liquid propane tanks (cylinders) require a vaporizer on the mower. Clean Scapes ran mowers with this configuration for roughly six years. It worked OK, but Tintera says the need for a vaporizer seemed like an unnecessary step. Now the company uses vapor propane cylinders that eliminate the need for a vaporizer.

Even though Clean Scapes’ on-mower propane configuration has been simplified, Tintera says it is still important to ensure that each mower is set up properly before placing it into production.

“Anybody can slap a propane conversion kit on a mower,” Tintera says. “But you don’t just do that. There are testing gauges and sniffers to help tune your mower appropriately. It’s actually called stoichiometric ratio, which is the ratio at which fuel burns with air. That ratio is 14.7:1. If you’re tuning the mower correctly to that ratio, any power loss will be so slight that you probably won’t even notice it. On the other hand, if you just slap a kit on and go, you’ll probably be looking at 30% power loss.” The lesson for landscape companies? Make sure you are working with a reputable dealer that understands and believes in propane. And if you’re going to rely on in-house technicians, acknowledge the fact that they are going to need some propane-specific training.

Speaking of training, landscape companies will also need well-defined processes regarding the storage, refilling and overall safe handling of propane.

Get a handle on propane handling

Several Sebert Landscaping branches have invested in their own on-site propane fueling infrastructure. A handful of employees at each branch are trained and authorized to refuel the propane cylinders from a large storage tank. This helps limit the amount of training necessary while establishing better control, safety and accountability.

“There is a cost to getting your on-site fueling system set up,” Bitler says. “But with proper training and procedures, you can save money over time because you don’t have the cost of paying a propane supplier to constantly come and fill up your tanks.”

Bitler says it’s important for employees to understand that, unlike with gasoline, the objective isn’t to fill the tank as full as possible. With liquid propane, you only want the cylinder filled to 70-80%. “The cylinder needs to be vented out and not overfilled so the mower doesn’t end up sucking in liquid,” Bitler says. “The mower needs to be fueled by the propane vapor only. This is why it helps to limit the people authorized to handle the refilling.”

Some landscape companies prefer to have their propane supplier handle the refilling. This is especially true for smaller fleets with less than 10 mowers. One option is a cylinder exchange program where the supplier stops by your facility on a predetermined basis to pick up your empties and drop off properly filled cylinders. Another option is to have the propane supplier refill your cylinders at your facility. The latter has worked best for Clean Scapes.

“Between our branches in Austin, Dallas, San Antonio and Houston, we go through at least 1,000 gallons of propane a week,” Tintera says. Given that volume, the supplier is more than willing to visit each branch daily to refill Clean Scapes’ cylinders.

“I know all of our drivers personally and that makes it easier,” Tintera says. “Building a good relationship with your propane supplier is really important. If there ever is a problem, like a valve breaking off on a cylinder, you need to have someone you can call.”

Even with a great supplier who takes care of the refilling, employees still need training on how to safely work with the propane cylinders.

Clean Scapes employees go through a program on how to safely change out propane cylinders in the field. Generally speaking, Tintera says a 33-pound cylinder will provide for a full day (roughly five hours) of blade time. But in those instances where a cylinder needs to be changed out, Tintera says the process is relatively easy.

“A hose on the mower screws into the fitting on the cylinder,” Tintera says. “Then it’s just a matter of using the two straps to secure the cylinder in the saddle mounted on the mower.”

Leak detection is another area that requires some training.

“Propane has an odorant added to it that our employees are trained to smell for,” Tintera says. “If they smell it, they are also trained on how to search for a potential leak, which is basically using soapy water (to look for bubbles). And just for an added safety measure, each mower has a Class B fire extinguisher strapped to it.”

Leaks happen very rarely if at all, Tintera says. In fact, one of the overlooked benefits of using propane relates to waste. “With pre-filled propane cylinders, we have zero spillage in the field,” Tintera says. “We don’t have employees dripping gas on the ground and we don’t see gas leaking out of cans while riding around on our box trucks.”

Zero spillage can add up to some serious money over the course of a season, especially for a large fleet the size of Clean Scapes’. The safety level is also a lot higher. When coupled with the primary benefits of reduced emissions and fuel cost, there are several reasons why a landscape company would consider using propane. With good planning to address any potential productivity issues, the pros could very well outweigh the cons.

The author is a freelance writer based in Wisconsin.