T.V.s there. And what they found was a huge range in the stand-by power of these devices. And some of them, not just televisions, but other kinds of appliances, were leaking as much as 20 to 25 watts. And you found other televisions that were less than 2 watts, and there was no difference in price for these devices. It was just that the manufacturers hadn't really thought about it for a long time. NARRATOR: But as even proponents of energy efficiency admit, human behavior seems to be moving in the other direction. Americans are buying larger homes and larger vehicles. JOHN B. HEYWOOD, Sloan Automotive Laboratory, MIT: We are buying larger, heavier vehicles, so the average weight and size has gone up. The engines and transmissions we use have got a little more efficient, and the two things are roughly canceling out. So the technology is getting more efficient, but the miles per gallon aren't getting better because we're steadily buying larger- more larger and heavier vehicles. So we have this choice. We could all drive smaller vehicles, and they would use less fuel and put less CO2 into the atmosphere. But that's not our current choice. NARRATOR: But perhaps the biggest barrier to reducing greenhouse gases is economic growth. American industry uses energy more efficiently than at any time in history. The Andersen Window Company, which makes the top-of-the-line energy-efficient window, is no exception. But ironically, because business is booming, they use more energy than ever before. Because