In 1997, NPS installed 3 solar hot-water systems at Oklahoma’s Chickasaw park. 2 years later, the largest system supplied 18,194 kWh annually, replacing electric heating

In 1997, the National Park Service replaced electric heaters at Oklahoma’s Chickasaw National Recreation Area with three solar hot-water systems. Built with the National Renewable Energy Laboratory, the project tackled high utility costs at campground comfort stations. Within two years, the largest system produced 18,194 kilowatt-hours annually. The installation recouped its investment in eight years while cutting long-term energy demands.