UofL converted one of its push mowers from gasoline to propane last year to see if using the alternate fuel was viable, said grounds superintendent Aaron Boggs. The conversion worked so well that Physical Plant is now switching over its entire mower fleet—eight push mowers, five riding mowers and two walk-behind mowers—to run on propane, he said.

Mowers powered with propane burn up to 30 percent less fuel, generate less carbon waste and are safer and easier to maintain than mowers powered with gasoline.

The technology for using propane to fuel mowers is fairly recent, Boggs said.

“We’re one of only a handful of universities in the country doing this,” he said.

 UofL bought conversion kits for its mowers from Metro Lawn Propane Conversions, a company based in Dandridge, Tenn., that also is helping show Physical Plant groundskeepers how to use the modified mowers.

Each converted mower will carry one or two cylinder-shaped metal propane tanks, depending on its size. A sealed hose running from the tank to the engine delivers propane to the mower. All of the mowers are getting special stickers on their gasoline caps that read “No gasoline.”

“Now we can mow the grass even on ozone alert days,” said groundskeeper Jim Hart, who helped convert UofL’s first mower to propane. “The emissions are that much lower.”

Boggs doesn’t know exactly how much money UofL will save from making the switch, but he plans to do a cost comparison in about a year.

“If this goes well, we may convert our string trimmers, leaf blowers and other groundskeeping equipment to propane, too,” he said.

The U.S. Environmental Protection Agency estimates that garden equipment engines produce up to 10 percent of the nation’s air pollution. Studies show that a conventional lawn mower pollutes as much in an hour as 40 late model cars.

In 2009, UofL launched a $21.7 million, 13 ½-year project with Siemens Building Technologies Inc. to make the university more energy efficient. Energy savings from that project are expected to reduce UofL’s annual greenhouse gas emissions by 55.5 million pounds, an amount equal to removing 4,600 cars from the road for a year.