Whether many forms of solar energy are practical for wide-spread use is still debatable. Solar collectors for industrial heat are restricted to favorable geographic locations. Photovoltaic cells that turn sunlight directly into electricity are competitive only for specialized applications, such as the microwave repeater stations in Australia that bring telephone service to the “outback.” But passive-solar architecture, which merely configures houses to take maximum advantage of the sun, is clearly parctical anywhere in the contiguous United States.
Buildings can be designed to block the rays of the high summer sun. They can absorb the warmth of the low winter sun, store it in wall masses, and release it as needed at night and on cloudy days. Shortly after the energy embargo of 1973, the American Institute of Architects estimated that passive-solar design would add little to the cost of buildings yet save half of their energy costs. In the decade since, one might have expected homebuyers to demand passive solar and builders to employ it.
That hasn’t happened. At the Passive Solar Update Conference, held by the Department of Energy (DOE) last October, speakers repeatedly chided the building industry for its failure to incorporate passive-solar features in homes. The 300 largest builders in the country, responsible for 40 percent of new homes, do not use passive solar, according to Summer Rider Associates, a New York public-relations firm with numerous builders as clients.
“The housing industry has not been innovative,” agreed Mike Bell, manager of energy programs at the National Association of Home Builders (NAHB). “Builders react to market trends instead of setting them.” But Bell said that a couple of the big companies have experimented with passive solar. “If homebuilders wanted to market passive solar, they could,” said Harrsion Franker, an architect in Princeton, N.J. He suggested that this would allow consumers to lower their monthly costs: slightly higher mortgage payments would be offset by lower utility bills. And Mark Conkling, project director of the New Mexico Showcase of Homes, a consortium of 16 builders who are putting up affordable passive-solar housing was more optimistic. “We’re past the early adopter stage,” he said, “but not yet into the mass-market stage.”
Even when U.S. builders incorporate passive solar, they generally “tack on” features–a less effective and more costly method than integrating energy efficiency into the overall design, according to Paul Kando of the NAHB Research Foundation.
The foundation’s annual survey of NAHB members provided some insights. Of thousands queried, only 772 builders–most with small operations–responded to questions on solar, and just 108 of these had built any passive-solar homes in 1981. Furthermore, one-third of these builders of passive solar had failed to include all the components that comprise a passive-solar system. As defined by the Department of Housing and Urban Development, these include collection, storage, distribution, and control features requiring little or no external power.
The problems from these poorly integrated systems have been predictable, said Kando. Buyers’ complaints, as expressed by builders in the survey, include too much or too little heat and fading carpets and furniture.
The majority of builders who avoided passive solar found its cost intimidating. Kando blamed this on the lack of an integrated approach to solar architecture: “putting solar glazing on a sieve is like trying to justify a gate without a fence.”
Some builders were skittish about experimenting with passive solar in a slumping market. Most complained that information on passive solar was hard to find. Charles Hauer, a consultant to the DOE Passive Solar Program, suggested that passive solar, might simply be too complicated for most builders. He referred to Don Aitken, a successful passive-solar builder in California who holds degress in physics, architecture, and mechanical engineering. If this is the kind of education it takes to build passive solar, Hauer seemed to be saying, we might as well forget it. Consumerism
Another common complaint about passive solar is that consumers are not interested. At the conference Conkling explained that 99 percent of home buyers seek good financing, 63 percent look for microwave ovens, 30 percent are swayed by “romantic and spacious bathrooms,” but only 1.5 percent base their decisions on solar.
Conkling urged builders to give consumers what they want and include solar in the deal. His consortium of builders in New Mexico provides 9.5 percent financing on houses costing $75,000 to ,105,000. Builders who lack Aitken’s education can calculate energy savings from a worksheet the consortium uses, which is complex but no worse than income-tax form 1040. Because Los Alamos National Laboratory developed it, the worksheet carries weight with local bankers, some of whom allow people to quality for higher mortgages based on projected energy savings.
The NAHB Research Foundation concluded that good passive-solar designs are cost-effective, and that builders’ and consumers’ ignorance of this fact is the biggest obstacle to widespread use of passive-solar design. The foundation urged the DOE to continue monitoring test houses through the Passive Solar Program to provide the information builders need. But Kando warned that recent cutbacks could kill the monitoring program just as results are due.