Testing Consumer Electronics for Energy Efficiency

Head into the CNET labs to learn how CNET's editors test consumer electronics for energy efficiency.

Mark: Hey, I'm Mark Licea and we have a special end of the year show this week where we tour the Cnet labs and show you how our editors test their products for power consumption. The Green Show starts now. Hey I'm here in the labs with our senior editor David Katzmaier. He reviews HD TVs for Cnet. And he’s going to tell us how we test for power consumption. So David, what is the first step when you're testing this TVs for energy efficiency? David: Actually one of the first steps is dictated by the energy star protocols to warm the TV up. So TVs kind of fluctuates if you don’t warm up for a little bit, so we use an hour long warming period to get them kind of fired up. We just turn them on whatever they come out of the box, their default settings and let them run for an hour. Mark: And what kind of technology is involved in the testing process? David: We use a relatively sensitive power meter. It’s a Chromo meter, we plug the TV right in to it and it measures the wattage and a lot of other different factors. But watts is what really what we care about. So we just plug it in this meter. The meter measures things automatically once per second, and kind of give us an average afterwards. There's a specific disk that use to test with, so we use the same disc every time. And there's also, in addition to the energy star protocol, we actually test for a calibrated with post calibration setting. So we set up the TV to specific light output which equalizes the power above beyond regular default settings. We also test the power saving mode in the TV to see how efficient that is. Mark: And how do you determine energy rating for each TV? David: Well every TV has a range of good, fair, or poor. And we pretty much divide all the TVs we tested right down into 33%, 33%, 33%. So the bottom third gets a poor and the middle third gets a fair, and the top three gets a good. Mark: So what are the biggest factors in determining power consumption? David: There's three major factors, the screen size. Of course the larger TV consumes more power. There's technology, plasma use more power than LCDs and these a lot of variation between those categories. Different type of LCDs more or less power LED is very efficient for example. And also the picture setting itself. So how bright you set the picture, which is often determine by the picture mode. Mark: And how all this information translates to how much you pay annually? David: That’s a really good question. Actually, people think that TVs consume a lot of power, but actually the annual number is relatively low. For example, even the least efficient type of TV of plasma in a 46 inch range calibrated for a dark room which is relatively dim is only going to use about $65 per year, with average energy cost. Of course there's a lot of fluctuation, screen size, and technology between those. Some TVs use as much power as a 60 watt light bulb. Mark: Have you notice any changes from the manufacturers to be more green? David: Yeah, actually the TVs have been getting a lot more efficient year over year. Even the plasmas have been getting more efficient. But again, this new technology introductions like LED and getting the LCD TVs to be a lot more energy efficient, have been really kind of improving a lot. Mark: Great, thanks for that. Next, let's head over to Dan Ackerman in the computer labs to talk about how they test laptops and desktops. So Dan, you're going to tell us how all the power testing magic happens here in the labs. So give us the run down. Dan: What we started doing is taking every desktop and every laptop that comes in to the Cnet lab and hooked them up to a power meter much like this one. Then we take the machine and we run it through a whole different usage scenario that kind of mimic what you’d actually do with the machine during the course of a year. We test it while it’s off, because you know, it’s till drawing some current from the wall. We test it while it’s asleep, because your machines spends a lot of time asleep. We test it while it’s kind of idle, just sitting here. And then we actually run a whole bunch of program. We call that a load test, and see how much power it draws when its actually doing the stuff that you do with your computer all the time. So then we take this data and we actually work that in to the reviews. So any review you look up at Cnet is going to have that number and in comparison to other similar systems. You see which one uses the least power. Mark: So what's a typical price range for a laptop or a desktop? Dan: Well you can start it well under $5 if you have a very energy efficient machine or if you have a big gaming rate. Whether it’s a desktop or a laptop. It can go $20-$30, even more, but that’s still not a lot. Considering you're using the machine for a full year. Mark: And what's the difference between testing laptops and desktops for power consumption? Dan: Well, again for power consumption, we actually do run the same test on desktops and laptops. We run a slightly more involve load test when we’re testing gaming machines because you're going to use those to play games, which is more intense than just surfing the web. Mark: And what about products that you use recycled materials, less packaging? Dan: Well, we’re seeing a little bit of that. Kind of like the beginning of that road in terms of computers desktops and laptops. We obviously have seen a couple of manufacturers that you send your old product back when you buy a new one. So that they'll recycle your old laptop or desktop. And of course we’re seeing some guys move away from the traditional Styrofoam packaging to packaging with more cardboard parts in it. And we’re even seeing a handful of systems starting to hit the market that have a guaranteed percentage of post consumer recycled content in them. Mark: We also monitors for power consumption, but the process is very similar to the way we test HD TVs. And that does it for 2009. We won't have new episodes of The Green Show until mid January. And I want to thank everyone for writing in with your support and feedback on the show. Happy holidays, until next time. I'm Mark Licea. Thanks for watching.