Eco4planet: tela preta para ajudar ao planeta?

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Comentário de Angela em 24 novembro 2009 às 10:44

muito interessante! vamos adotar a idéia, eu e meus queridos alunos!!!!!parabéns!

Comentário de Moderador do Banco do Planeta em 22 novembro 2009 às 7:33

Olá Sérgio,

Agradecemos a sua contribuição!

Saudações,
Equipe Banco do Planeta

Comentário de Sérgio Morelli em 22 novembro 2009 às 5:56

Por Sérgio Morelli | thesm@bol.com.br |

Estudo comprova que uso de sites com fundo preto aumenta o consumo de energia em monitores LCD

Olá, economizar energia é uma boa idéia, porém sabemos que não devemos acreditar em tudo que aparece nas teias da Internet. O site http://techlogg.com prova que o uso do fundo preto, em sites, gera economia de energia apenas para quem usa os antigos monitores de CRT, e que pelo contrario, aumenta o consumo de energia para quem usa os modernos monitores LCD, hoje 75% da base mundial ativa. Vale citar que este argumento foi citado para geração de economia de energia, e foi utilizado por diversas organizações e sites de busca, sem estudos mais aprofundados.

Na esfera "eletrônica" tudo é obvio e exato, a lógica de economia de energia, com uso de imagens pretas, é válida apenas para monitores CRT - Tubos de Raios Catódicos. Para realmente economizar energia com seu monitor LCD basta um conjunto de simples ações: diminuir o brilho e contraste, desativar a proteção de tela com imagens e ativar o desligamento automático do monitor.

Para ajudar o meio ambiente compre aparelhos que consumam menos energia. Substitua lâmpadas incandescentes e as "novas velhas" compactas, que contem mercúrio e outros gases que prejudicam a camada de ozônio, pelas modernas Lâmpadas LED, de silício orgânico que duram mais de 15 anos e consomem apenas 1watt com uma intensidade equivalente a uma incandescente de 40watts. Compre e use uma bicicleta e principalmente reutilize sacos plásticos o máximo de vezes possível. E para quem ainda não escreveu um livro, que tal plantar uma, duas, três... árvores. A natureza agradece.

Abaixo veja os estudos dos sites http://techlogg.com

Wikipedia:
When a voltage is applied across the electrodes, a torque acts to align the liquid crystal molecules parallel to the electric field, distorting the helical structure (this is resisted by elastic forces since the molecules are constrained at the surfaces). This reduces the rotation of the polarization of the incident light, and the device appears gray. If the applied voltage is large enough, the liquid crystal molecules are completely untwisted and the polarization of the incident light is not rotated at all as it passes through the liquid crystal layer. This light will then be polarized perpendicular to the second filter, and thus be completely blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, light can be allowed to pass through in varying amounts, correspondingly illuminating the pixel.

July 2009
Black & white power consumption - 24 more LCD monitors tested
As part of a recent review of 24 LCD monitors we undertook for Australian PC User’s July 2009 issue, we also grabbed some extra power consumption measures using full black- and white-level displays to see again if black screens cause a reduction in power consumption.
The 24 review samples came from seven manufacturers from AOC through to Samsung. We used a commercial Australian-made AC power meter to measure the power consumption along with a simple software tool to generate complete black and white screen displays via a PC to each monitor. Brightness levels were set to 100% on each unit.
Power consumption (Watts)
100% brightness level
Monitor Screen Size (inches) Black screen White screen % reduction
AOC F19s 19 20.9 20 4.31%
AOC F22 22 41.6 40.4 2.88%
Asus MK241H 24 90.7 89.8 0.99%
Asus VH192C 19 20.8 20.2 2.88%
Asus VH232H 23 43.7 41 6.18%
Asus VW225T 22 37 36.3 1.89%
BenQ E2200HD 22 41.1 39.9 2.92%
BenQ G2400WD 24 44.6 44 1.35%
BenQ M2200HD 22 42.4 41.1 3.07%
Dell 2209WA 22 80 83 -3.75%
Dell C22W Crystal 22 49.1 47 4.28%
Dell G2210t 22 24.3 22.3 8.23%
LG Flatron W2242T 22 43 40.1 6.74%
LG Flatron W2261V 22 41.4 40.2 2.90%
LG Flatron W2284F 22 45 42.7 5.11%
LG W2252TE 22 23.9 21.8 8.79%
Philips 190BW 19 24.6 23.8 3.25%
Philips 220XI 22 43.3 41.6 3.93%
Philips 221EI 22 38.9 38.2 1.80%
Philips 230C1 23 47.6 45.8 3.78%
Philips 240PW 24 95.8 101 -5.43%
Samsung SyncMaster 2233sw 22 41 39.4 3.90%
Samsung SyncMaster 2333sw 23 42.9 40.9 4.66%
Samsung SyncMaster 943BW 19 33.6 33.2 1.19%
AVERAGE 44.05 43.07 3.16%
As you can see from the results, only two of the 24 monitors (italicised) tested saw a reduction in power consumption going from a white to a black screen. They were Dell’s 2209WA and the Philips 240PW. These both use IPS (in-plane switching) rather than the standard TN (twisted nematic) panel construction. The other 22 monitors all saw a reduction in power consumption going from black to white screen displays.
As far as we’re concerned, this sinks the idea that power consumption can be reduced by using black search engines or backgrounds. The average power consumption drop was nearly one-watt or 3.16% of total power consumption.
Backlight (brightness) reduction gives more
However, whether you have a black or white-screened search engine, background or whatever is almost irrelevant when you compare the power differences here with what can be achieved by simply dropping the backlight (brightness) level. We’ll look at this in more detail shortly, however, as our testing has shown, the backlight accounts for as much as 60% of the overall power consumption of an LCD monitor and that dropping it even just from 100% to 70% can produce up to a 20% drop in power consumption without seriously affecting the screen’s visibility.
What’s equally important is that this drop in consumption through brightness reduction occurs regardless of the type of LCD construction used. And that makes arguing over black or white LCD screen backgrounds almost pointless.
This entry was posted on Wednesday, September 23rd, 2009 and is filed under Environment News. You can follow any responses to this entry through RSS 2.0. You can leave a response, or trackback from your own site.
Blackle vs Google power savings
We’ve boosted our testing to now include 27 monitors so we’re now pretty certain we know what to expect after our final series of tests.
UPDATE 31 March 2008: Hi everyone. Some respondents have mentioned that LCD brightness has an affect on power consumption. Well, it certainly does. We carried out a small test last October and wrote up the results in a story called “Backlight consumes two-thirds of LCD monitor power”
Our tests on Blackle versus Google has been reported on by major newspapers and sites around the world. Well, while a few people have managed to pull out a monitor or two to test how much power they consume running the two search sites, we think we’ll have to last word.
27 monitors.
Yep, we’ve tested 27 monitors, including some 23 LCD monitors, to find out once and for all how both of these search engines stack up on monitor power consumption. We’ve taken a range of sizes and brands to try and get the most reliable test results possible. There’s no argument that on CRT monitors, Blackle does reduce the power consumption but it’s not by the 15-watts claimed. We tested the four CRT monitors we could get our hands on and found that only one unit, an older 22-inch Compaq, showed the 15-watts or more power differential.
But with the LCD monitor market penetration worldwide now beyond 75%, it’s the LCD monitor power consumption that’s just as, if not more, important. The most interesting aspect we found was that of the LCD monitors we tested of size 22-inches or less, all showed an increase in power consumption using Blackle. Beyond the 22-inch mark however, five of the six models showed a fractional decrease in power consumption when using Blackle, except the ViewSonic VX2835wm, which showed a 2.2-watt increase.
For the five that dropped their power consumption, the average drop was 3.16-watts, again, not the 15-watts being suggested. But for the sake of fairness, here’s what we suggest – if you’re using a CRT monitor, you can save some power by using Blackle however it won’t be as much as its supporters will have you believe. We still think it’s around half. If you’re using a 22-inch or smaller LCD screen, stick with Google if you want to keep power consumption to a minimum. However, if you have a 24-inch or larger LCD monitor, on average, Blackle is the cheaper option but it’s not a guarantee – as we said, we found one 28-inch LCD monitor that bucked that trend.
However, the power consumption difference between Google and Blackle on all 23 LCD monitors was as small as you could get – an increase of 100mW (0.1Watts). So after all that testing, we’re in a better position to say that anyone else that Blackle makes next to no difference, on average, with LCD monitors. If you’re really serious about saving energy, here’s just a couple of tips that will make far more difference: switch off your computer at the end of the day and don’t bother with a screensaver, because every screensaver costs power to run.
UPDATE August 10, 2007 - If you’re serious about wanting to save power with your computer, read this story. We’ve outlined five simple ways based on our tests that we can all use to help save amounts of energy that far exceed what you can do with a search engine.
Darren Yates is a B.Sc. (electronics) graduate of Macquarie University, Sydney, Australia.
Size
(inch) Resolution (pixels) Google
(watts) Blackle
(watts) Power difference (watts)
LCD
models
LG SW570LE 15 1024×768 26.2 26.5 -0.3
AOC LM721 17 1280×1024 33.1 33.5 -0.4
Acer AL1916W 19 1440×900 28.3 28.8 -0.5
BenQ FP93G 19 1280×1024 31.1 31.9 -0.8
LG L1917S 19 1440×900 33.3 33.4 -0.1
LG L192WS 19 1440×900 24.5 25.1 -0.6
LG L196W 19 1440×900 38.6 39.7 -1.1
ViewSonic VX1932wm 19 1440×900 35.5 36 -0.5
Asus VW202 20 1680×1050 35.7 37.2 -1.5
BenQ FP202W 20 1680×1050 43.6 44.3 -0.7
Acer AL2216W 22 1680×1050 30.5 32 -1.5
Asus PG221 22 1680×1050 54.9 55.9 -1
Asus VW222 22 1680×1050 43.2 43.4 -0.2
BenQ FP222W 22 1680×1050 40.7 41.9 -1.2
LG L226W 22 1680×1050 39.9 42 -2.1
Samsung 226BW 22 1680×1050 43.6 44.8 -1.2
ViewSonicVX2255wmh 22 1680×1050 41.3 42.4 -1.1
BenQ FP241W 24 1920×1200 87.4 85.2 2.2
Dell 2407WFP-HC 24 1920×1200 82.7 81.3 1.4
NEC LCD2490WUXi 24 1920×1200 73.7 69.6 4.1
NEC LCD2690WUXi 26 1920×1200 89.3 85.2 4.1
ViewSonic VX2835wm 28 1920×1200 106.8 109 -2.2
Samsung 305T 30 2560×1600 111.5 107.5 4
AVERAGES 51.1 51.2 -0.1

CRT models
Acer AC915 19 1280×1024 75.9 64.6 11.3
Compaq P1210 22 1280×960 112.6 96.2 16.4
Digital PCXBV-HY 15 1024×768 73.6 65.1 8.5
Mitsubishi DV1770 17 1024×768 72.5 65.4 7.1
AVERAGES 83.7 72.8 10.8

Comentário de Adolfo Emmanuel em 21 novembro 2009 às 20:57

Eu adotei essa idéia...