Green computing Large HD televisions are voracious electricity consumers. Some 50in plasmas demand in excess of 400W of power when turned on. That's more than a good-size, modern refrigerator. Here are some tips to reduce the drain.

To minimise your home-theatre bills, you need to examine both what you buy and how you use it. The good news is that you don't have to cut back on your entertainment hours in order to save money and to reduce your carbon footprint.

Buy green

Here are some guidelines to consider when you're shopping for an HDTV.

Remember that small is beautiful: Everyone loves to watch a wall-size picture, but a bigger screen isn't better for the environment. On average, according to a study conducted by CNet, 42in plasma TVs use of 271W of electricity, versus 341W for 50in models. That's a difference of more than 20 percent in the smaller screen's favour.

Buy the right technology: Avoid plasma and you'll save electricity. A typical 52in LCD TV, uses 278 watts of power - only a tad more than a typical 42in plasma. Rear-projection sets (I know, they're not cool) save even more energy: On average, a 56in DLP TV runs at 171W. The new LED-lit LCDs save power, too. Our tests show that the 50in Samsung LN55A950, the first such television that we've got our mitts on, uses about 38 percent less power than most 50in HDTVs.

Look for the Energy Star 3 label: When the Energy Star label appears on a TV, it means that the set lives up to the EPA's standard for energy efficiency. But some companies go beyond that standard. Sony, for example, says that all of the 1080p models in its 2009 lineup surpass Energy Star 3.0 requirements by 15 percent. Sony's VE5 Eco line goes even further; the 40in VE5 can have a power savings topping 50 percent, and the 52in model can save 65 percent. Check the Energy Star website for a list of qualifying HDTV models.

Look for the manufacturer's 'green' angle: Many manufacturers have gone to great lengths to improve the energy efficiency of their 2009 models. Besides watching for the Energy Star designation, look for other energy saving options that a manufacturer may tout. For example, models in Sony's Bravia VE5 series - the Bravia KDL-52VE5, the Bravia KDL-46VE5 and the Bravia KDL-40VE5 - feature high-efficiency HCFL backlighting, which uses reduced-size cathode tubes to improve power efficiency by 40 percent over other Sony LCDs. They also feature a 0W standby power switch, a light sensor with dynamic backlight control to reduce the screen's brightness for use in dim environments, and a motion sensor that turns off the TV if it doesn't detect any movement for a specified period of time.

Watch the power consumption of your components: When buying components, pay attention to the relative power supply and the reported watts consumed for each device. You can find these specs for many devices, including Blu-ray players and DVRs, on the back of the unit. That's how I found out that my Sony Blu-ray player uses 25W and that my Dish Network DVR uses 120 watts. Manufacturers' websites sometimes list this information, but it can be buried in obscure places. Though amplifiers/receivers proudly advertise their wattage per channel (more is better for sound quality), you can always save power by lowering the volume.

DVRs are a special case when it comes to power savings. You can't completely shut off a DVR without losing its scheduled recording ability, but an eco-conscious DVR will consume only a trickle of power when "off" and waiting for a signal from its timer or from the remote to come back to life. The popular DVR TiVo doesn't quite reach this ideal mix: Even in its hard-to-reach standby mode, it keeps spinning the hard drive and recording whatever is on two different channels. TiVo says that the DVR consumes about 39W when on, and "slightly less" in standby mode.

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