This July, as part of an ongoing effort to make its operations as green and economical as possible, the Forest Preserves of Cook County converted 16 new gasoline-fueled large riding lawn mowers to propane power.
Most people already think of the Forest Preserves as being green—after all, the Preserves’ 69,000 acres account for the largest area of preserved natural areas in Cook County. But maintaining all that open space requires a lot of vehicles and fuel. To mow the lawns in picnic groves and other recreational public spaces, the agency maintains a fleet of 65 large riding mowers (16 of which are now propane-fueled), 102 push mowers and 108 line trimmers, all in heavy use from April through October. Beginning with the factory conversion of these 16 new Gravely Pro-Turn 472LP mowers, the move toward propane will significantly lower the environmental impact of grove maintenance.
“Our overall goal is to update our fleet, making it as environmentally friendly and fuel-efficient as possible,” said Forest Preserves of Cook County President Toni Preckwinkle. “This is a benefit to our community, the environment and a value to taxpayers.”
Shifting to propane has both environmental and economic benefits. Propane, also known as liquefied petroleum gas (LPG), comes from both the refining of crude oil and processing of natural gas. It is nontoxic and water insoluble, making it much less likely to contaminate soil and water than gasoline. Unlike gasoline, propane is a liquid only when under high pressure (as in a tank), so any leaks evaporate and dissipate, preventing fuel from entering ground or surface water. Perhaps most importantly, propane burns more cleanly than gasoline or diesel, reducing greenhouse gas emissions by approximately 26 percent and carbon dioxide emissions by 60 percent, as well as reducing emissions of other air pollutants.
The fuel switch will also save the Forest Preserves money. By converting to propane from unleaded gas in these 16 mowers, the Forest Preserves will save approximately $0.89 per gallon. The use of propane also extends engine life and reduces refueling time in the field. A federal conversion incentive cut the cost of conversion by $1000 per mower, making each new mower $826 to convert.
To fuel the mowers, the Forest Preserves is constructing nine fueling stations. The propane supplier, AmeriGas, will cover the entire cost of the propane tanks and related equipment.
The move toward propane in the Forest Preserves’ fleet will take place in phases, with the District currently pricing propane conversions for our 25 new Ford Interceptor police sedans. The District has been using biodiesel fuel in all its diesel vehicles for the last eight years and has been studying the costs and benefits of adding additional fuel-efficient vehicles.