Warm Up to Solar Heating
May 27, 2008
With Colorado’s 300-plus days of sunshine per year, solar thermal heating is becoming a popular way to use the sun’s rays for something other than outdoor recreation.
Most of us equate the sun with heat, for obvious reasons. It’s only natural that during a time of increasing energy costs and the green building movement we use that heat in our homes and buildings, says Eric Westerhoff, owner of Innovative Energy in Breckenridge.
But solar thermal heating isn’t new. Under President Jimmy Carter, the federal government gave rebates for solar installations as part of his 1977 National Energy Plan.
Solar energy businesses, like Mike Tierney’s Aspen Solar Systems, soon began popping up all over the country. Tierney, after 25 years in business as a Western Slope solar contractor, is happy to see that interest in the technology has taken off again in recent years.
“It had only been going on in little hot spots,” Tierney says. “Whereas now, over the last three years, there’s been incredible growth.”
What does solar heat do?
Solar heating works through panels installed on southward-facing roofs. The sun heats the panels, which in turn heats water. That water is used for all of the daily activities in the home requiring hot water ” dishwashing, showers, laundry ” but it also can be used to heat the home via a technology called radiant floor heating.
“It is really the most comfortable form of heat there is,” Tierney says.
Radiant floor heat uses solar-heated water to heat the floor mass, which is typically concrete that can be covered by most types of flooring, such as carpet, tile or wood. Tubes embedded into the concrete warm up and circulate water, which keeps the floor consistently warm.
“Everywhere you go, everything is the same temperature,” he says. “There are no cold spots.”
It’s extremely efficient, says Matthew Charles, of Grid Feeders in Avon. Hot air rises, so the floor’s heat will not only keep feet warm, but also that heat will radiate upward.
Solar-heated water won’t necessarily replace the traditional gas boiler or furnace, but it will create less of a need for them.
“The furnace will come on; it just won’t come on as hard,” says Bill Jaap, an Eagle resident who built his home with solar thermal panels. “When everything is functioning properly, the gas portion doesn’t run as long, and that’s where the (cost and energy) savings come in.”
And the more solar panels, or collection areas, there are on the roof, the less auxiliary heating homeowners need from boilers or furnaces,
Installing solar into the home
Most contractors will tell you that building a home with solar from the ground up is probably the easiest way to go, but retrofitting isn’t as difficult as it sounds. Tierney says there always seems to be a way to integrate the panels and the piping so that it doesn’t appear to be a retrofit. The roof where the panels will go should be mostly southward facing, though a little to the southeast or southwest doesn’t hurt.
A retrofit can be more expensive, he says, but not overwhelming.
“You address the technology with the building,” Charles says.
Megan Gilman, president of Active Energies, an energy consulting company in Avon, says space in the mechanical room as well as the distance from that room to the roof can make retrofits difficult. Piping must connect the panels to the water storage tank, and “if you’re talking two stories down to a mechanical room, there’s some work to be done for sure,” she says.
As for upkeep, there’s a little, Jaap says. Since pumps circulate the hot water, a power outage can turn into a mess. On a sunny day last summer, the power went out in his home and blew the system because it overheated.
“You have to watch it and make sure everything is functioning,” Jaap says.
Aesthetically, the panels can be a bit distracting. Tierney has been working with more and more architects in recent years to help reduce some of the visual design problems.
Doug Graybeal, a green architect in Carbondale, says he’s been integrating the panels into his design so they fit flat into the roof, “so it’s not as much of an eyesore.”
If money, rather than reducing your carbon footprint, is the number one reason for turning to solar thermal heating, Graybeal says it’s “pretty much a no-brainer.”
Charles says it’s one of the most viable energy technologies, and it carries one of the lowest base and installation prices.
The systems can last as long as 30 years, he says, and the initial return on a smaller system can be felt in as little as five years. For an average size four-person home ” approximately 3,000 square feet ” it would cost about $10,000 to put in a system that would cover about 70 percent of the domestic hot water production, Charles says.
The payback could be even sooner for someone looking to sell a home. In cold climate areas, prospective buyers tend to ask to see last year’s energy bills. It makes a home with solar that much more attractive, he says.
The formula that Grid Feeders uses comes from a study done by a California real estate organization. It basically says that for every dollar saved in early operating costs, the home value increases by $20.
And there are government incentives for installing solar thermal and solar electric systems, both at the state and federal levels.
Regardless of the payback in dollars, Westerhoff, of Innovative Energy, says people should be concerned about paying the Earth back.
“We get 300 sunny days a year (in Colorado),” Westerhoff says. “And if Mother Nature is offering that to us, we’d be rude not to accept it.”