Saturday, October 17, 2009

News You Can Use - LCD TV Edition

I recently read an LA Times news report about new energy efficiency regulations that have been proposed in California for televisions.  The draft proposal by the California Energy Commission implies that TV manufacturers are not using the most efficient technologies available and could easily reduce the energy consumption of new TVs by almost 40% by 2013.  

I was skeptical to say the least.  Most new televisions use LCD technology that's an outgrowth of the computer laptop market.  Manufacturers of computer laptops have been relentless in their attempts to reduce laptop power consumption to improve battery runtime.  If there were any easy LCD power savings available, I was sure the marketplace would have already ferreted them out.  

So I decided to dig a little further into the draft proposal and I found my answer on page 10 of the report.  Although there's plenty of hand waving about potential innovations that might reduce television power consumption, the real reason why dramatic power reductions can be achieved without increasing cost is this:

Significant reductions in energy consumption can be achieved in Plasma and LCD TVs by adjusting the contrast and brightness screen settings by manufacturers before shipping TVs to the retailers. The power consumption of the TV drops significantly with screen setting modifications. On average, plasma TVs will consume almost 21 percent less power when set to a low power factory preset, sometimes called “movie” or “pro” settings.

Ok.  Now  we're getting somewhere.  Apparently, television manufacturers ship TVs to retailers with the brightness max'ed out.  This gives their TVs greater showroom appeal.  Unfortunately, it also causes the TV to consume more power than needed, and unless consumers lower the brightness once they get the sets home, power is wasted.

Now this is news I can use.  I decided to test out the theory with our Samsung LCD TV.   First, I measured the TV's power consumption with the default factory settings.  My trusty kill-a-watt meter showed a reading of 160 watts.  Next, I  adjusted the brightness to its lowest level.  Surprisingly, there was only a slight drop in power consumption, so I returned this setting back to its default.  Next, I noticed a "backlight" setting on the TV's display menu.  I adjusted the backlight from 5 down to 2.  With that, I saw a dramatic reduction in power consumption - from 160 watts down to 116 watts.  Given the lighting conditions in the room, this low setting seemed pretty workable.  

This simple change reduced power consumption by 44 watts per hour.  According to Wiki Answers (if it's on the Internet, it must true, right?), the average American watches over 8 hours of TV per day.  This means that the average household could save 128 kW per year of electricity (44*8*365/1000) or around $20.   

That may not sound like much savings, but when you consider that it's free money, and also consider the reduction in greenhouse gasses from reduced power plant emissions if everyone makes the change, it seems like it could be worth it.  Of course, now that we're armed with this new information, we don't have to wait for new regulations to start saving.

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