The Natural Resources Defense Council has conducted a study that places the spotlight on how inefficient cable boxes and DVR's are in American homes.

These boxes, which guide cable signals and digital recording capacity into televisions, run at a constant rate and can utilize more power than a new refrigerator or air conditioning unit.

According to the study, there are 160 million set-top boxes in the U.S., and this number is increasing. These boxes run 24 hours per day, even when they're not being used. The study found that add-on DVR's use an additional 40 percent more power than the set-top box. 

The Natural Resources Defense Council found that these boxes consume $3 billion in electricity per year in the U.S., and 66 percent of this power is drained when no one is even using it. Also, one high definition cable box and one high definition DVR use about 446 kilowatt-hours per year, which is 10 percent more than a 21-cubic-foot refrigerator that is energy efficient. 

The study notes that the problem here is that these boxes' hard drives are constantly on, which is a design made by electronics companies and cable/internet providers. There is a way of changing this feature, but these fixes are not being mandated in the U.S., even though these fixes could reduce waiting time and inconvenience associated with these boxes.

"The issue of having more efficient equipment is of interest to us," said Justin Venech, spokesman for Time Warner Cable. "[But] when we purchase the equipment, functionality and cost are the primary considerations."

Some countries in Europe already have boxes that go into standby mode or deep sleep mode when not in use. This reduces energy consumption by 95 percent, and when a cable box is in deep sleep mode, it only takes one or two minutes to reboot. 

"I don't want to use the word 'lazy,' but they have had different priorities, and saving energy is not one of them," said Alan Meier, a scientist at Lawrence Berkeley National Laboratory, of the industry in the U.S.

John Wilson, a former member of the California Energy Commission who is now with the San Francisco-based Energy Foundation, remembers asking box makers why the hard drives ran even when they're not in use, and the typical answer was, "Nobody asked us to use less."

But now, the Environmental Protection Agency plans to strengthen its Energy Star standards by 2013. Some of today's boxes have obtained the Energy Star seal and do not possess standby or sleep modes. But according to Noah Horowitz, senior scientist at the natural resources council, many of these boxes have an on/off button that just dims the clock and doesn't significantly decrease power use. Also, he noted that cable boxes are not designed to be turned on and off entirely, but adjusting the software over a cable could greatly improve energy efficiency. 

As of September 1, average electricity consumption of Energy Star qualified products are to drop to 97 kilowatt hours a year from about 138, and by the middle of 2013, they must decrease to 29 kilowatt hours per year. Cisco says it plans to offer new box models this year that will comply with the new regulations by cutting energy consumption by 25 percent. It will do this by adding a standby mode, but not a sleep mode.