Partners (Second Quarter 2004)
Partners (Second Quarter 2004)
|Making Energy Efficiency Affordable|
Energy conservation is a perennial subject. We all know the inherent value in reducing energy consumption to save money while helping the environment. But how many realize that energy efficiency is especially important for low- and moderate-income homeowners faced with utility bills that often absorb a significant portion of monthly income?
Granted, many builders of affordable housing are aware of the need for energy efficiency, and today’s construction generally includes at least some power-conserving features such as insulation materials and energy-rated mechanical systems and appliances. But the effectiveness of builders’ choices varies widely, and resulting energy savings tend to be relatively minor.
So why don’t builders focus more on constructing affordable houses that use minimal energy— or even generate their own energy through solar technology? The reason is obvious: the incremental cost of achieving this goal tends to exceed low- and moderate-income families’ budgets, even with the help of specialized financing products such as “energy efficient mortgages.” These mortgages allow a lender to stretch the standard loan qualifications, but the downside is increased financial burden for the homeowner. Although the higher initial costs of major energy-efficiency elements are eventually compensated by savings on power bills, the payback point at which energy savings allow families to get ahead tends to be far in the future. Nevertheless, some builders are finding a way to pursue this goal.
Solar technology for affordable housing
Affordable solar homes might seem like an impossible dream to most people, but Jeff Christian thinks otherwise. Jeff is the director of Oak Ridge National Laboratories’ Buildings Technology Center, and he’s forged a partnership with Habitat for Humanity in Loudon County, Tenn., to build solar Habitat homes in Lenoir City about 20 miles southwest of Knoxville.
Oak Ridge, a division of the U.S. Department of Energy, is also partnering in this project with the Joint Institute for Energy & Environment in Knoxville, Tenn.; the Department of Energy’s Building America program; and the Tennessee Valley Authority’s (TVA) Energy Right? program. As the region’s primary electric supplier, TVA recognizes the need to rein in demand that’s likely to outpace production capacity in the long run, if left unchecked.
Five homes have thus far been constructed in Habitat’s Harmony Heights subdivision, and more are planned. Each home is its own research project or “living laboratory” in which slight variations in design, materials and construction techniques help determine optimal combinations of features. For example, the first home uses a standard type of structural insulated panel (SIP) for the floor, walls and roof. The next two homes use different combinations of SIP types. Lead carpenters are trained to install the specialty features. As with other Habitat programs, volunteers contribute labor for the primary construction.
All the homes have solar technology, but they are still tied to the local electric grid. The cost of energy consumption is offset by the home’s generation of solar energy, which is contributed back to the power grid. This creates a credit for the homeowner that’s applied against the cost of electricity. To date, the average net utility cost of the solar homes has been approximately 50 cents a day or about $15 a month. That’s for an all-electric home with central air and heat. The ultimate goal of combining energy-efficient design and solar panels is to achieve “zero-energy” homes—ones that generate sufficient solar power to cover all of the energy needs of a typical family.
Making the numbers work
A major hurdle in affordable, energy-efficient housing is the cost of solar panels and other high-energy construction. In the case of the Lenoir City subdivision, the incremental costs run approximately $15,000 to $20,000 per house. However, extra costs have been mitigated so that homebuyers end up paying the same as for a standard Habitat house.
Donations of energy-efficient material from many manufacturers and suppliers have helped to lower construction costs. While these groups display business acumen in promoting their products, they are also committed to achieving the project’s long-range goal—creation of comprehensive whole-house “kits” that can be sold at a reasonable price through mass production, as solar technology continues to improve and manufacturing costs come down. By the year 2010, Jeff anticipates that the “kits” will bring the price of today’s energy efficient solar homes in line with that of conventional affordable homes.
Spreading a good idea
The more units of energy-efficient, affordable homes that are built over time, the more viable the program will become to local housing authorities, nonprofits, developers, funders and other partners interested in affordable housing. Many such partners have a passion for the subject because they understand the significant impact lower power costs will have on their clients. “Eco-friendly” or “green” features can also enhance eligibility for affordable housing tax credits, and this is another reason those concerned with affordable housing find the program appealing. The success of the program also helps educate consumers to understand the benefits, and this leads to increased demand.
Acknowledging the great potential that exists for this market, Jeff notes, “A key part of this project is getting the public and builders to visit the homes and learn about them. We’re proving that energy-efficient, affordable housing can be achieved for real families today, and we’re poised to be able to help many more families in the near future.”
For more information on solar technology for affordable- housing developers,
contact Jeffrey E. Christian at firstname.lastname@example.org or visit www.ornl.gov/btc.