To take advantage of the energy-saving opportunities, some product standards would have to be tightened and some policy incentives changed. Current regulations and fuel subsidies, for example, often favor consumption over efficiency. But many steps are not taken, the report said, because energy users lack information or do not value efficiency enough to change their buying habits.

“The opportunities are huge and yet they are being left on the table,” said Diana Farrell, director of the McKinsey Global Institute, a research arm of the McKinsey consulting firm. “Standard economics would say that energy prices would work their way through everything. But that’s not really the case, particularly in the consumer market.”

That is especially the case, according to other energy experts and executives, if an energy-thrifty product has a slightly higher purchase price and the financial payoff for users takes a while. That helps explain the slow progress made by compact fluorescent light bulbs in the marketplace. Years ago, these efficient light bulbs cost up to 10 times as much as conventional incandescent bulbs, and their light had a somewhat different hue.

But today, the light spectrum has been corrected and compact fluorescents are only slightly more costly than conventional bulbs, yet they last 10 times as long and consume 75 percent less electricity. The overall financial advantage of using compact fluorescent bulbs is obvious and sizable, even if the initial purchase price is higher.

“One of the great mysteries is why the public has not shifted faster to fluorescent bulbs,” said Alexander Lidow, a Stanford-educated physicist and the chief executive of International Rectifier, a maker of power management equipment for energy-efficient appliances.