Historically, owners of lodging establishments throughout the United States and Canada have ignored the sun as a source of potential energy to heat water. Whether because of concerns about cost or misperceptions about how solar thermal technology works, solar hot water heating systems have been rare.

That is all beginning to change, however, thanks to improving technologies, tax incentives and rebates, creative financing, better education about solar thermal heating, an increase in the number of developers interested in building to Leadership in Energy and Environmental Design (LEED) standards, and an increase in the number of qualified vendors that sell and install solar hot water heating systems.

How does solar thermal energy work? If you have returned to your car and opened the door after the car has been sitting in the sun for an hour, you have experienced solar thermal energy. According to the website www.solar-is-future.com, in a typical solar hot water heating system, solar collectors absorb the sun's rays, convert them to heat and then transfer that heat to a heat-transfer fluid. The heat-transfer fluid is typically a glycol and water mixture in regions where seasonal freezing is a concern.

"The heat-transfer fluid is then pumped into a heat exchanger located inside the water storage tank where it heats the water," the website says. "After releasing its heat via the heat exchanger, the heat-transfer fluid flows back to the collectors to be reheated. The controller keeps the heat-transfer fluid circulating whenever there is heat available in the solar collectors. In the winter, a boiler serves as an alternate heat source. Solar thermal systems can be integrated into existing hot water systems with relative ease."

Appropriate for Any Location

One might conclude that solar hot water heating is only an option for properties in southern locations but that is not the case. The sun generates enough energy even in northern locations to make solar thermal systems feasible. For example, the Confederation Place Hotel in Kingston, Ont., has a 20-panel rooftop solar hot water heating system and the Best Western-Kelowna in Kelowna, B.C., has a 102-panel system.

"It pretty much works anywhere, from both a technological and financial standpoint," says Kirk Norlin, vice president marketing for Novan Solar Inc., Golden, Colo. "New England, for example, may get less direct sunlight but those living there pay more for their energy, so it makes sense."

Norlin says 90 percent of the time roofs can bear the weight of a solar thermal structure. Adequate roof space is important and of course access to sunlight is key. A building rooftop cannot be shaded for a good portion of the day.

Other properties that have installed solar thermal systems include the Proximity Hotel in Greensboro, N.C., the new Andaluz hotel in downtown Albuquerque, N.M. (not yet open), the Park Place Hotel in Ocean City, Md., the Hyatt Regency Scottsdale Resort and Spa at Gainey Ranch in Scottsdale, Ariz., the Lodge at Sun Ranch in Cameron, Montana, and the Kanuga Lake Inn in Hendersonville, N.C. A large-scale solar water heating system is being installed at the Hilton Asheville in Biltmore Park Town Square in Ashevelle, N.C. That property, which is seeking LEED certification, is expected to open this summer.

Proximity's System is a Success

The solar thermal system that has perhaps gotten the most buzz is the 100-panel installation at the Proximity Hotel. The panels cover 4,000 square feet on the roof of that LEED Platinum certified hotel. The water heated by the Proximity’s system -- approximately 5,000 gallons a day -- is saving the property about $16,000 in water heating-related costs per year, according to Dennis Quaintance, CEO and CDO (Chief Design Officer) of Quaintance-Weaver Restaurants and Hotels, the company that owns the property.

The system cost Quaintance-Weaver Restaurants and Hotels about $400,000, more than a typical system for a property the Proximity's size, primarily because the owners chose to build a concrete structure and extra floor to support it. Even with the extra costs, however, the company should recover its investment in four to five years. Annual energy savings, having the ability to sell renewable energy credits (RECs) for $20,000 a year for the first five years, a 30 percent federal tax credit, 35 percent state tax credit, and being able to take advantage of a provision for accelerated depreciation of $84,000 are all shortening the time needed to recover the initial investment. The solar hot water heating system has been meeting 60 percent of the hotel’s domestic hot water needs -- the equivalent of the amount of water needed for 100 houses for one year. The solar system is backed up by natural gas for those days when supplemental energy is needed.

"Each panel in the Proximity’s installation is like a mini greenhouse," says Michael Shore, president of FLS Energy, the company that installed the Proximity's system.

"I keep asking myself, 'Why didn’t we do this before?' " Quaintance adds. "It makes so much sense to do solar thermal."