Solar Carries a Swimming Pool Through the Winter

You don’t often see an outdoor swimming pool high in the Colorado Rockies, unless it’s fed by a natural hot spring. That’s because the sub-zero nights and sun-warmed days create a freeze-thaw cycle that will buckle the bottom of a pool emptied for the winter.

The town of Eagle-Vail, just west of the Vail ski area, budgeted $3.6 million for two new pools: a six-lane 25-meter competition pool and a 40-foot by 16-foot kiddy pool complete with sprayers and a slide. The plan was to prevent frost heaves by keeping the pools filled all year, with the water circulating through a heating system and insulated pool covers in place through the winter. Natural gas and electric heaters were prohibitively expensive to run. A solar thermal system fit the bill.

Bruce Padgett, president of Capitol Solar Energy in Denver, installed 17 insulated glazed Solene collectors, set at a steep angle to shed snow. This array operates all year, pushing warm water through the pools all winter. When the complex opens in the spring, a secondary array of 37 unglazed Heliocol panels brings the pools up to swimming temperature. An IMC Eagle 2 system handles control functions. A back-up gas heater carries the pools through multi-day winter storms, but the community estimates that the solar system saves about $10,000 a year in energy costs. Padgett’s bill came to $86,000, so payback should take less than 10 years.

Construction began in April 2010, and the pools opened for Thanksgiving. The complex then closed for the winter, reopening on Memorial Day, 2011. The system performed as designed through the winter.