David Watkins, a supervisor for a local builder, has a personal residence which utilizes extensive solar energy technology for power, water heating, and the HVAC system.

Columbia Home & Garden presents the second of a two part series exploring the idea of using solar energy to heat, cool, and power our homes. In the previous issue we described passive solar energy techniques, which involve site orientation and design elements to either utilize or discourage the sun’s natural heat in creating a comfortable interior atmosphere. This time, we delve into what’s known as active solar — that is, capturing the sun’s light to generate electricity, in some cases enough to sell back to the power company itself!

As a source of energy the sun can’t be beat — after all, it’s the engine that drives all the natural processes on earth. So why aren’t more consumers choosing solar to actively produce the energy they require?

The answer’s an easy one — active solar has yet to prove itself as an affordable, mass-market renewable energy solution.

For now, most consumers must still rely on an electrical utility to power their homes, but the addition of PV panels to a structure could, under the right conditions, produce enough power to allow a homeowner to actually sell back a portion of this energy to the utility, what’s known in the industry as ‘net metering.’

Bi-directional metering from SCE & G, customer generated. The surplus is sold back to the power company.

As noted in the prior article, local architect and solar energy advocate Pete von Ahn emphasizes again that, for all its attractive and green advantages, going solar isn’t the first step in reducing energy costs. A home energy audit, in which a structure’s thermal envelope is tested and evaluated, remains the initial and most important step in the process of reducing the cost of electricity.

Either as an adjunct energy source, or, for the most ambitious homeowners, getting off the grid entirely, using active solar energy technology requires much more than photovoltaic, or PV, panels on the roof converting sunlight to electrical power — the solar energy enthusiast must also store this power for when the sun isn’t shining, a process that in the words of von Ahn would require either a large closet, or even a whole room, devoted solely to storage batteries.

Todd Wagstaff, president of Comfort Services of the Midlands, agrees with von Ahn that homeowners seeking to lower costs should pursue an energy audit before considering further technological solutions. Improving a home’s thermal envelope with insulation and radiant barrier products, inspecting ductwork, and other such steps should be taken before installing a new HVAC unit, or pursuing more exotic energy solutions like solar panels, Wagstaff says.

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There’s no doubt that a renewable energy source like solar panels makes good sense, only that the upfront costs remain formidable. A Lennox product that Comfort Services offers called SunSource, in which an integrated, single solar panel is designed to partially power the HVAC system, adds an additional $2000 to the price of a new unit, and depending upon a variety of installation factors, individual PV cells in a larger array can run up to $3000 apiece.

Despite these costs, Wagstaff says that SunSource was a big hit for Comfort Services — in 2009, his company sold more of these units than any other Lennox dealer in the country. When he saw how much interest was being shown among consumers and fellow industry professionals alike, Wagstaff felt very excited about solar. “Here we go,” he thought, feeling that a tipping point in consumer acceptability was rapidly approaching.

Both Von Ahn and Wagstaff emphasize that a driving factor in such success, and a key component in future adoptability of solar technology, however, are government tax incentives offered toward the purchase of renewable energy solutions — incentives that here in South Carolina weren’t especially attractive in the first place, and that have since either lapsed or been diminished.

Solar panels on the roof on the back side of the Watkins house. The large panels are water, and the small panels are photovoltaic.

“For a time we had high-energy efficiency air conditioning credit and a solar incentive that, bundled together, drove revenue and interest in adopting solar,” Wagstaff says. “And while I think that South Carolina wants these incentives; with other budgetary issues, they can’t seem to figure out how to afford them.”

Another obstacle in adopting solar technology is that the per-kilowatt hour cost of electricity in our state remains comparatively low. With high upfront installation costs and only modest back-end tax subsidies, a full solar-cell array could have a cost recovery period that’s measured not in years, but decades — and in these troubled economic times, that’s a tough sell to the average consumer.

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But the technology is improving, and costs are declining, though not at a precipitous rate. Power companies all over the country facing rising demand, however, aren’t looking to renewable energy so much as planning to expand traditional infrastructure. “We’re spending billions of dollars to subsidize power companies to build new nuclear facilities,” Wagstaff notes, “yet we can’t find the political will to subsidize a homeowner to use renewable energy sources.”

Wagstaff continues, “The day will come, I hope in my lifetime, when solar becomes viable, but with today’s technology, there just isn’t a solution yet that’s a silver bullet.”

So, active solar power remains among many steps consumers should consider for future energy needs, but for now, scheduling an energy audit with either the power company, or a private firm like von Ahn Design or Comfort Services, remains the first, and best step homeowners should consider taking. In deciding how best to fuel our homes and lives, an old maxim would seem to hold true: knowledge equals power.