Green Scene: Up on the roof

Rising energy costs, atmospheric carbon levels and global temperatures are spurring interest in harnessing solar power, but the upfront cost of installing such systems is often a substantial deterrent. Public institutions face the same hurdle as individuals: how to justify buying an expensive solar-energy system that could take 20 years to pay for itself.

Sometimes the little things make a difference. Asheville City Schools is now implementing some of the recommendations from a 2009 energy audit, including such low- or no-cost measures as removing lights from vending machines and turning off unused appliances in summer — which could save the system up to $259,000 annually, according to the audit. Grants from Progress Energy and the State Energy Office are paying for more efficient lighting in 31 school gyms. Following all the audit’s recommendations — including such substantial capital improvements as installing energy-efficient windows — is projected to cut greenhouse gas emissions by some 11,600 tons over five years.

Meanwhile, the Buncombe County Schools is considering replacing Enka High School’s aging furnace with a state-of-the-art rooftop solar array that could generate enough energy to meet the building’s heating, cooling and hot-water needs (except, perhaps, on cloudy days) while producing a surplus that could be sold for a tidy profit.

“Should we go down this road?” Tim Fierle, director of facility services, asked Board of Education members on Feb. 7

Other local schools already have. The Joe P. Eblen and Charles T. Koontz intermediate schools, now under construction, will feature rooftop solar panels and will be LEED-certified upon completion. Meanwhile, Henderson County’s two newest elementary schools, both opened in 2009, are already LEED-certified. The U.S. Green Building Council’s Leadership in Energy and Environmental Design program certifies that buildings are built to specific performance standards.

When green means greenbacks

In the case of Enka High, what’s creating this opportunity is the conjunction of significant federal and state tax credits with a burgeoning trade in renewable-energy certificates, Asheville architect John Legerton points out. The N.C. General Assembly has mandated that by 2021, most utilities in the state must generate 12.5 percent of their energy from renewable sources, he notes, and many other states have similar policies.

To satisfy those mandates, utilities across the country are buying renewable-energy certificates (a separate commodity from the actual electricity produced), and trading them is becoming quite lucrative for these “solar developers” and their financial backers.

The Enka High project, said Legerton, who has an extensive background in environmental design, could be a significant moneymaker for the district. A solar developer could lease the school’s roof space and install a solar heating-and-cooling system. During the lease period, the county schools would continue buying electricity from Progress Energy (current average cost: 9 to 10 cents per kwh); the developer, meanwhile, would sell the electricity generated by the school’s solar panels back to the utility for about 18 cents per kwh. The legal mandate to purchase renewable energy is what has created this price differential.

The developer would assume all the costs and risks of installing and operating the system; after seven years, the county schools could purchase the infrastructure for a depreciated, fair-market value. At that point, said Legerton, Enka High could generate most of the electricity it needed while getting income from sales of both the surplus power and the renewable-energy certificates.

Meanwhile, the system would also be producing thermal energy. During the contract period, the school system would be buying what was needed to heat and perhaps cool the high school directly from the solar developer at a negotiated rate, which Legerton said should be less than what it currently costs heat the school using those aging boilers.

Unlike independent solar operators, who must first cover the cost of their equipment, the county schools would enjoy immediate cash flow through the lease arrangement, Legerton maintained. And if the school bought the system after seven years, its utility bills would be slashed dramatically.

The catch: For the developer to take advantage of the tax credits, the project would have to be completed by December. That’s a tight schedule, considering that an analysis of the building’s existing mechanical systems, plus some necessary roof renovations, plus developing a request for proposals, selecting the winning bidder and negotiating a lease would all need to be completed by June to make the end-of-year deadline feasible.

At its March 3 meeting, the school board voted 5-1 to pay Legerton $52,000 to assess the existing infrastructure. Lisa Baldwin cast the lone opposing vote, questioning the wisdom of spending the money while facing the prospect of teacher layoffs and continuing state budget woes. Once the assessment is done, the board will decide whether to proceed with soliciting bids.

— Direct your environmental news to Susan Andrew (251-1333, ext. 153, or sandrew@mountainx.com).