Sunday, February 01, 2009

Google�s Big Shadow, Small Feet

According to this Telegraph article, for about thirty minutes, a Google search was flagging every non-Google web site and some of its own with the warning �This site may harm your computer�. What caught my eye, though, was the following sentence:
Google is so popular worldwide, earning �3bn in income during 2008, that it has been claimed 750 megawatt-hours of electricity could be saved every year if the home page was changed from white to black.
Now that sounds like a lot of money and electricity. But by way of comparison, look at Toyota, whose latest operating income forecast (January 6) for 2008.4-2009.03 shows a precipitous 73.6% year-on-year drop, yet still clocks in at 0.96 trillion yen, or �7.3 billion (�1=\131). Google must be well ahead of Toyota in terms of its ubiquity as well as its lead over its competitors, but even in a bad year, it still has a long way to go before it can overtake the manufacturer. And there�s a much, much greater gap in revenue.

Now let�s see what kind of equipment it takes to produce 750 megawatt-hours per year. Assume a power generator that runs 24/7, 300 days a year. 750 MWh�24h�300d)=104.16 kW, which gives you the output of this generator. Yanmar is a leading manufacturer of small power generation systems and equipment. It offers a series of standby diesel generators, of which the smallest one has an output of 100 kW*. In other words, the electricity savings from the home page color switch would be barely enough to run a small hospital, if that**.

I bring this to your attention not to trivialize Google in any way; rather, I was struck by the fact that the economic and environmental footprints of something that has such an enormous impact on our lives are so small. Also the fact that the Telegraph threw out a number that made no specific point as such, but I�m beginning to bore myself with my incessant rants against the mainstream media.

* Yanmar also has a range of smaller emergency systems to meet minimum safety requirements. The minimum here is 17.6 KW. The Yanmar web site is inconsistent so I went with the catalogued items.

** The Google home page savings occur over 365 days, so the actual day-to-day savings and the corresponding capacity requirement for the standby system would be proportionately smaller. But downtime needs to be absorbed into the overall demand on the public power grid, so I believe that my example gives a better sense of the dimensions.


Janne Morén said...

That savings idea is interesting to me since it's an example of old truths no longer holding as technology advances.

The idea is that a CRT monitor that paints an image needs to shoot a stronger beam the brighter the color, with no beam at all for pitch black. So a black screen with a little white text would use much less energy than a white screen with a little black text.

But CRT monitors are becoming rare today, supplanted by LCD monitors of various stripes. And they have an always-on light source that is blocked or not by the individual liquid crystal pockets on the screen surface. As the light source stays the same the energy use doesn't change at all.

And in fact, it may be worse - for LCD monitors, a white screen will in fact draw slightly less power than a black one. First, for some LCD technologies darkening a pixel draws energy while brightening it does not. Second, as a practical matter, when the screen is white and bright the users will tend to lower the screen brightness, and so reducing the power use of the backlight.

Graham said...

Google search was flagging every non-Google web site and some of its own with the warning "This site may harm your computer"

Actually, they even flagged themselves, according to TechCrunch's screenshot.

On Google's power use implications, there's been some controversy...

Jun Okumura said...

Janne: That’s fascinating. The second point about LCD monitors is particularly instructive because it highlights the human element that can foul up the best plans.

Graham: Thanks The Sunday Times appears to have been a big story for techies, this article being a fairly thorough one, including some relevant links, that also reflects unfavorably on the ST.