Something in your entertainment system is gobbling up power - and it's not your TV. With more people buying larger-screen TVs, a lot of attention and concern have been directed at TV power consumption -- with states like California adopting legislation that prohibits the sale of TVs that don't meet strict energy standards. But the fact is, TVs are growing increasingly efficient, especially the new LCD models that use LED lighting.

Additional Resources
• Read more original stories in our Feature News section.
• See more stories like this in our Satellite Receiver and HD DVR News section.
• Explore satellite receiver and HD DVR reviews on HomeTheaterReview.com.

No, the real hog is quietly hiding in the shadows of that new TV. It's your cable/satellite set-top box or DVR. The National Resources Defense Council recently released the results of a study called "Reducing the National Energy Consumption of Set-Top Boxes," which contains some surprising findings about our beloved DVRs.

According to the study, there are about 160 million set-top boxes in U.S. homes. In 2010, those boxes consumed approximately 27 billion kilowatt-hours of electricity, equal to the annual output of nine average (500 MW) coal-fired power plants. The electricity required to power these boxes results in 16 million metric tons of carbon dioxide emissions and--here's the one that might really get your attention--costs households more than $3 billion each year. As much as it pains us to hear this, the HD DVR is the worst offender, consuming 40 percent more power per year than a non-DVR set-top box.

Why do these boxes consume so much power? In a nutshell, they operate at nearly full power even after you've hit the Off button; there's no low-power standby mode in place. The NRDC estimates that $2 billion of that annual $3 billion cost comes during times when we aren't even using the box. It's not just a hardware problem, either. The New York Times has published an interesting piece on the NRDC study, entitled "Atop TV Sets, a Power Drain That Runs Nonstop," that explains the service providers' role in set-top box power usage.

Okay, we know the problem. What's the solution? As I mentioned above, people were paying a lot of attention to TV power consumption, so the manufacturers felt more pressure to improve efficiency. Nobody's been talking about set-top boxes (well, some people have probably been talking, but few have been listening). The NRDC hopes that, by drawing more attention to the issue, STB manufacturers and pay-TV service providers will feel inclined to design more efficient boxes that consume much less power when they're not being used. The group also recommends that consumers ask their service provider to supply them with a set-top box that meets the more stringent Energy Star 4.0 standard.

Another way to cut down on set-top box power consumption is to cut down on the number of set-top boxes. The NRDC encourages the shift to whole-home solutions that don't require a dedicated set-top box in every room. I think that's a solution we can all get behind.

Additional Resources
• Read more original stories in our Feature News section.
• See more stories like this in our Satellite Receiver and HD DVR News section.
• Explore satellite receiver and HD DVR reviews on HomeTheaterReview.com.