The National Mall and Memorial Parks (NAMA), a unit of the National Park Service, received a donation of six propane-fueled Exmark Lazer Z S-Series lawn mowers with Kohler Command Pro Propane EFI engines from the Propane Education & Research Council (PERC). These are the NAMA’s first and only alternative-fueled lawn mowers. PERC’s donation amounts to approximately $70,000 in equipment, according to PERC.

The four 72-inch and two 60-inch Lazer Z S-Series propane-fueled zero-turn riders will comprise one-third of the Mall’s mower fleet and replace diesel-fueled mowers. The mowers will be refueled using a propane cylinder exchange system from Thompson Gas.

PERC and Greater Washington Region Clean Cities Coalition celebrated the first use of the mowers on the Mall on June 24 in addition to the park’s adoption of two electric cars and charging stations at a ribbon-cutting event. The combined deployment of alternative-fuel vehicles and mowers added NAMA to the list of national parks advancing the Green Parks Plan, a National Park Service initiative to reduce dependence on foreign oil, mitigate the effects of climate change, and conserve energy.

Switching to propane mowers will lower carbon monoxide emissions by 80 percent compared with gasoline, reduce fuel spills, and save NAMA money on fuel and maintenance costs, according to PERC. A byproduct of domestic natural gas processing, the U.S. produces more than enough propane to meet current demand and became a net exporter of the fuel in 2011.