Yellowstone National Park, Wyoming, has many historical sites within its boundaries. One of these is the Lamar Buffalo Ranch, a ranch that was set up in the early 1900s to breed buffalo for replacement stock within the park during a time when their numbers were very low. The ranch buildings are currently being used by the Yellowstone Association Institute for ecology classes.
Since the ranch is located in the northeast corner of the park it is quite isolated from the commercial power grid, and power has been traditionally supplied by propane generators. The generators are now only a backup system for a 7kW photovoltaic (PV) array, which provides approximately 70% of the building group's energy needs. This is Yellowstone's first PV system. The system was installed by the park staff with guidance and sponsorship from the Federal Energy Management Program (FEMP).
Initial investment: $81,000
Payback period: 11.6 years
Cost savings: $7,000/year
Energy savings: 14,000 kWh/year ($0.50/kWh)