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Old Fashioned TVs are Still Greenest

by Jann Swanson -
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The choices confronting anyone in the market for a new television are pretty staggering; especially for us old fogies raised in the era of massive 19 inch black and white mahogany clad consoles in the living room.  Now add to the decisions about display type, screen size, and price a concern about picking the most energy efficient boob tube.

 

According to the Environmental Protection Agency, the various types of televisions available today are Plasma, Liquid Crystal Displays (LCDs), and Flat Screens in addition to the familiar Cathode Ray Tubes (CRTs.) 


 

Plasma televisions have “emissive” displays.  The panel is self lighted with the plasma or gas causing pixels to glow.  A pixel or “picture element”  is the smallest item or dot of information displayed on a television screen, thousands of which make up the picture.

 

LCDs have “transmissive” displays because there is an independent light source, a bulb, behind the screen which shines through the liquid crystals to create the display.

 

The very latest innovation is OLCD technology – Organic Liquid Crystal.  These screens are reported to be brighter, thinner, and have greater color contrast than LCD displays but it is an emerging product, the jury is still out on a lot of the facets such as durability, but they seem destined to be a major player in the television market.

 

Flat screens are a diminishing concern as all screens are growing thinner and flatter.  In fact even CRT’s are available with flat screens which reduce glare but don’t necessarily have the picture capabilities of LCDs and Plasma displays.

 

We will leave decisions about the picture quality you must have and the size screen you are willing to pay for up to you, but we can offer a bit of guidance on the green issue.

As television screens grew to mammoth proportions it quickly became apparent that they were also becoming mammoth energy hogs.  According to the California Energy Commission current LCDs use about .27-watts per square inch and plasmas use 0.36-watts per square inch.   In contrast, a CRT uses .23-watts per square inch.  A set to set comparison is not possible because CRTs are not manufactured in quite the giant economy sizes of the other two types of display, but here is one example, also from the Commission:  a CRT with a 30 inch screen – very generous size for that type – uses 101 watts.  An LCD that is 42 inches in diameter uses 203 watts and a plasma screen of the same size uses 271 watts.  Thus, from an energy standpoint, the choice is pretty clear cut.

But, if you must have a home theater-style viewing experience, help is on the way but probably not in time for the next Super Bowl.

 

Recently Energy Star, the joint EPA and Department of Energy program that rates the efficiency of appliances and electronics, issued standards for its certification for televisions which took effect last November.  California is debating and may already have passed rigorous and controversial standards which some say will reduce the number of television models that can legally be sold in the state by 25 percent.  However, California usually sets the environmental standards for manufacturers and if the law passes they will no doubt scramble to comply.

 

To qualify to display the Energy Star logo, a television must operate in the on mode to meet the formula for its type and size range.  For example, all standard (non-HD) sets, regardless of size must fall within the following formula:  PMax = 0.120 * A + 25 where PMax is maximum power, and A is screen area.  Screens of less than 680 square inches are governed by PMax = 0.200 * A + 32, a screen size falling between 580 square inches and 1045 square inches is measured at PMax = 0.240 * A + 27 and a screen greater that 1045 square inches at PMax = 0.156 * A + 151.  Thus a HD set with a screen 32 x 50 (1,600 sq. in.) will be limited to consuming 400 watts of energy.  A 42 in. (754 sq. in.) screen would have a maximum energy use of 208 watts.  

 

According to Power Integrations, by the time the Energy Star specifications became effective, over 300 models were ready to meet them.

 

California’s more stringent standards would not just be certification standards like those of Energy Star but would carry the force of law.  The regulations would come into effect in two stages, in 2011 and 2013.  With the second stage California expects to reduce television energy use by 49 percent and save the state’s residents between $18 and $30 a year per set.

 

Many experts expect that these new rules will be academic by 2013 as manufacturers continue to improve their products.  The higher consumption plasma sets are already losing popularity as the reliability and durability of LCD displays improve.

 

So, draw your chair a little closer to your smaller screen and hang in there.  In a year or two you will probably be able to cheer on a life size Bret Favre (of course he will still be playing, Lord knows for whom) while still taking pride in being green.


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on
This is somewhat skewed... 30 inch CRT is 4:3 ratio (more square) and has a height of 18 inches, width 24 inches for a total of 432 sq inches. 42 inch Plasma/LCD is 16:9 (more rectangular) and has a height of 21 inches and width 37 inches for a total 777 sq inches. When you see the LCD uses about double the power but has 80% more screen real estate it's not nearly as bad as it originally looks. I would also wonder if CRTs don't get more power hungry the bigger they get... I had a 36 inch CRT that gave off mamoth heat, that's gotta chew power.
on
You are no doubt right about the power consumption of really large CRT sets and that is probably the reason they are not widely available if at all. The reference to the 30 inch CRT came from the California Energy Commission, however according to Power innovations, the largest CRT made is 27 inches. The California .23 watt per inch figure, however, makes it pretty clear that the CRT is still the most efficient display.