The Chickasaw National Recreation Area is located 100 miles south of Oklahoma City, Oklahoma, on the Lake of the Arbuckles. To save taxpayers' money and minimize adverse impacts on the environment, the National Park Service (NPS) recently incorporated solar energy into the design of three new comfort stations.
The decision to use solar water heating at the site was the result of a collaborative effort between the National Renewable Energy Laboratory (NREL) Federal Energy Management Program (FEMP) and Solar Process Heat Program in support of NPS. Chickasaw visitors wanted hot showers, and park personnel wanted an alternative to conventional water heaters. The facility had electricity but no propane, and the cost of heating water with electricity was very high. "The demand for hot water coincides with the availability of sunlight, which makes solar water heaters the obvious choice," says Mark Golnar, a mechanical engineer with the NPS.
Solar collectors were installed on the southern roof of each of the comfort stations. Tanks store the hot water, 500 gallons each for the small stations, and 1,000 gallon tanks for the large stations. The solar-heated water is tempered with cold water to achieve a constant temperature of 105°F (411°C). The demand is minimized by the use of very low flow showerheads and one-minute push-button timers on the showers. The NPS plans to build a total of 25 comfort stations at the site.
Initial investment: $24,000 (large system), $18,000 (small system)
Payback period: 9 years (for small and large systems)
Cost savings: $867/year (small system), $1,789/year (large system)
Energy savings: 9,394 kWh/year (small system), 18,194/year (large system)