Putting Your Home on an Energy Diet

Putting your house on an energy diet is simple: airtight construction, smart heating and cooling design, and high-efficiency appliances. But simple doesn't mean easy. You might as well tell Americans they ought to lay off nacho chips and sign up for a daily Zumba class. The nation's power demands, like our waistlines, are growing ever more bloated.

Becky Clark and son Bradley outside their energy-efficient home, where electric bills are $1 a day or less.

(Charlie Archambault for USN&WR)

(USN&WR)

Look at just one of the new energy guzzlers: the digital photo frame. This always-on gadget burns a barely noticeable $9 extra a year into the average household electric bill, says the nonprofit Electric Power Research Institute. But the impact could be staggering. EPRI estimates that if every household in America owned one, it would take five medium-sized power plants just to keep those family photo slide shows rolling in the nation's living rooms. "I call these electronics the sleeping giants in our homes," says Thomas Reddoch, EPRI's director of energy utilization.

But there's a rising call for Americans to use less energy, either out of self-interested concern over escalating costs or genuine concern over the risk to the planet from global warming if the world's leading fossil fuel users continue on their current course. "The cleanest and cheapest kilowatt-hour is the one we do not have to produce," says Jim Rogers, chief executive of Duke Energy.

Goals. When the consulting firm McKinsey recently mapped out a possible pathway for U.S. carbon dioxide cuts at a cost that would not break the economy, almost 40 percent of the potential savings came from energy-efficiency steps that also would save people money. "It's a staggering amount of potential that could be an important step for achieving the carbon-abatement goals we have as a nation," says Ken Ostrowski, a McKinsey director.

Among the world's major economies, the United States is second only to Canada in energy use per person, but the nation's efficiency picture isn't all bad. Natural gas use per household is down significantly, thanks to vastly more efficient furnaces, better-insulated homes, and the population shift to the warmer South. As a result, overall energy use per U.S. household declined 26 percent between 1978 and 2001. But residential electricity use is surging, up 11 percent per household from 1993 to 2006 and 42 percent overall, as the number of gadget-filled households grows.

But research shows that with conservative measures that have fast payback, U.S. homes could become a third more energy efficient. "Green" builders everywhere know how to do it. Use 6-inch studs instead of two-by-fours for more wall cavity space to fill with insulation. In varying climates, use different kinds of high-performance windows to maximize sunlight or shield its intensity. And one simple, nontraditional step—designing ductwork so it's inside the home living space although still cleverly hidden—can cut family energy bills by a quarter to a third. Ductwork is so leaky that much of the heat or air conditioning in a home is lost. "Every time we build four new power plants to meet summer peak load, one of them is not necessary because it's generating nothing but cold air that's going into attics or crawl spaces," says Jeffrey Harris of the Alliance to Save Energy, a nonprofit coalition of business and environmental groups. The alliance is among groups pushing for a national minimum standard in building codes.

The National Association of Home Builders supports voluntary efforts but not mandates. "If you look at the places with more stringent energy requirements, you're looking at places with high housing costs," says Carlos Martín, assistant staff vice president of NAHB. "Especially in the market we have now, with foreclosures and people not able to afford even a slight price increase, that's a concern."

But a low-priced home is no bargain in the long run if it wastes energy. "You may pay a few dollars more on your mortgage payment, but you'll pay many dollars less on your utility bill," Harris says. "It's the sum of those, in cash flow to consumers, that really matters." Certainly, the payback on such investments is quicker in states with high electricity rates. But if the nation takes steps to cut carbon emissions, as seems inevitable, the price paid for fossil-fueled electricity will get higher even in states where efficiency makes less economic sense today. "These are half-century assets," Harris argues. "Why should we build infrastructure that basically is going to become another kind of dinosaur?" NAHB counters that the far bigger problem is the dinosaurs already among us: existing homes.

Reducing energy use in older homes is not easy. People are beginning to switch to twisty compact fluorescent light bulbs, which burn 75 percent less electricity than old-fashioned incandescents, with upfront costs recouped in less than a year. But the payback is neither so quick nor so clear on other items. Christine Rovner, director of Student Pugwash USA, a nonprofit that focuses on science and social responsibility, says she and her husband hired a heating and cooling system expert to advise them on steps they could take in their 60-year-old house in Washington, D.C. The windows, she knows, leak and need replacing, but she hasn't priced new ones. "We're too scared to," she says. She and her husband are weighing that possible outlay against other pressing costs, like day care for their young daughter and college savings. She thinks investing in appliances with the government's Energy Star label will be their next budget item. "We're watching our refrigerator and waiting for it to go," Rovner says.

Hogs 2.0. A swap to a new, efficient fridge would save enough energy to light the average household for nearly four months, Energy Star estimates, with an overall payback of about three years. But today, families can easily lose the gains they make in energy upgrades. At EPRI's Living Laboratory for Energy Efficiency in Knoxville, Tenn., researchers are tracking why the home electricity load is growing. Take, for instance, the set-top box—the converter needed to receive cable or satellite signals. These boxes are always in a ready state and draw as much power when they are turned off as when they are turned on. EPRI estimates each set-top box consumes about half the electricity of a new Energy Star refrigerator.

Of course, those set-top boxes are only one element of the home entertainment center. EPRI's testing shows that in energy use, those must-have 42-inch flat-screen TVs tower over the old 27-inch cathode-ray tube sets they're replacing. Reddoch notes that the traditional home centers of electricity use—heating, lighting, refrigeration, hot water—all have grown more efficient. "But the bad news is we've got this miscellaneous-electronics category—what we call the plug-in loads," he says. "They all are increasing."

Not far from EPRI's test center, researchers at Oak Ridge National Laboratory set out to prove how to drive down home energy use. Working with the nonprofit Habitat for Humanity and the Tennessee Valley Authority, they designed five homes with tight walls and windows, energy-sipping appliances, and ductwork inside the building envelope. The families, who didn't own homes before, helped build the modest three-bedroom dwellings. They pay $1 per day or less for electricity, while neighbors in similar homes fork over four to six times as much. Becky Clark says she has seen her monthly electric bill get down to $11 in the summer. And she likes that her 10-year-old son, Bradley, did a school science project on the home.

But electricity is still an essential fuel of our lifestyles. One December evening soon after the homes were built in 2003, Jeff Christian, Oak Ridge's director of building technology, rushed to see if the monitors were out of whack but found the sky-high readings were due to a festoon of Christmas lights and inflatable snowmen. He didn't mind: "These were families who had trouble affording to eat, who could enjoy the holidays this way because their electricity costs were so low."

But he'd like to see every house equipped with a little bit of solar energy, as the Oak Ridge scientists put on the rooftops of these homes. When the sun is shining and home energy use is low, the meter outside actually spins backward to show electricity savings. Solar panels are expensive, but Christian says the instant data on energy use would be worth it. "Then everyone could see how precious it is to collect energy from the sun," Christian says, "and how easy it is to shut off a light."