Sunday, February 15, 2009

Greener TV sets

With the changeover from analog to digital TV signals less than a month away, many of us are looking at TV upgrades to match. Given the choice between an LCD or a plasma, however, it's hard to know which to pick. Both use more energy than older CRTs (cathode ray tubes, the onetime standard for television technology), and both are made with nitrogen trifluoride, a chemical that lingers in the air for up to 550 years and one some climate scientists say has a bigger impact on global warming than the world's largest coal-fired power plants. The most earth-friendly decision you can make is to stick with your old CRT until it bites the dust, but when it's time for a new one, is there a truly greener flat-screen TV?
LCD TVs
What they are: Images are created when electricity passes through liquid crystals, a process that prevents screen burn (a problem with plasmas) and also reduces waste heat. The technology works at any size, allowing for smaller, less energy-consuming TVs. However, LCDs contain a fluorescent bulb, and a blown bulb means the end of the TV. As with all TVs, LCDs have plastic shells treated with brominated flame retardants and wiring that has various toxic heavy metals such as cadmium, chromium, antimony and beryllium.

Health: Brominated flame retardants, which attach to dust and get inhaled or ingested, have been found to trigger learning problems in children and to interfere with certain hormones. The other toxic materials are well enclosed and should pose little risk to users, but they could be released into the air or waterways during manufacture or disposal.

Life span: 60,000 hours

Screen size range: 12 inches and up

Energy Use: .12 to .37 watts per square-inch in full operation (about 106 watts for a 27-inch LCD); .32 to 76.11 watts on standby

Disposal: LCDs have the same disposal issues as plasmas (see next slide).
Plasma TVs
What they are: Electrically charged phosphors generate the extremely high resolution images and superior picture quality that make plasmas so popular. These TVs, however, generate excessive heat and have the potential for screen burn. And, like LCDs, the plastic cases and wiring contain brominated flame retardants and heavy metals.

Health: The health issues with plasmas are the same as with LCDs.

Life span: 30,000 to 60,000 hours, depending on the quality

Screen size range: 37 inches and up

Energy use: .18 to .62 watts per square inch while in operation. That's about 234 watts for a typical 42-inch plasma and up to 609 watts for larger screens. On standby, they use anywhere from .3 to 25.12 watts.

Disposal: Although more states now require electronics recycling, little attention is paid to where, exactly, all these recycled electronics are sent. Of those TVs that are recycled, half wind up in Africa, China or India, to be taken apart by poor families, including children, who are exposed to the lead, cadmium and other hazardous substances in TVs. According to U.S. News & World Report, nearly 80 percent of children in some major e-waste hubs suffer from lead poisoning.


Winner
It all comes down to screen size. On a per-square-inch basis, plasma energy consumption is just barely higher than an LCD's. But LCDs come in smaller sizes, and those small screens use less energy (both in production and at your house) and contain fewer hazardous chemicals than larger plasma screens. They'll even cost you less to operate—in some cases, $115 less per year than a plasma TV. Opt for an LCD in the 27-inch range; screens larger than that start using about the same energy and resources as plasmas.

When you do your shopping, look for the Energy Star label. Energy Star's recently updated television ratings judge TVs according to how much energy is used in full operation rather than how much it uses in standby only. Requirements vary depending on screen size, but any 42-inch Energy Star–rated TV, for example, must use less than 208 watts.

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