What If Yahoo, Google, MSN, Youtube and Myspace Turned Black?
In my last post I described how Google can save almost 15 MW energy per day if they switch to dark colored pages and as a result save $1800 PER HOUR for all users combined (at 12 cents/KWH) . This saving is excluding the synergistic savings the users will achieve (such as a tiny saving in air conditioning cost, because the monitor emits less heat).
Going back again to alexa.com, I see that yahoo has about the same reach as Google (around 25% of Internet users), but every visitor sees about 15 pages on yahoo, which is 3 times that of for Google. Keeping all our assumptions same, this means if yahoo switches from bright background to dark, the users will save of order of 45 MW.
Now this is getting interesting. The third ranked website as of today is Youtube. On Youtube people spend a lot more time per page watching video. Assuming most of them are not watching full screen version, can we assume that on an average a Youtube user sees the page for 2 minutes?
So Youtube’s percentage reach is about one third of that of Google. But page views per user is about 11. Let’s round it off to 10, which is double of Google. Also we assumed a Youtube user stays on one page for 2 mins, or 120 seconds (24 times that of Google). So now their total user-page-seconds will be (Google figure / 3)* 2 * 24 = Google figure * 16.
Agreed a big square on the website is the video playing, so we will reduce this by about 25% because that area is covered by video panel, color of which cannot be changed. Still the user-page-seconds figure of Youtube is about 12 times that of Google. That means 15 MW x 12 = 180 MWs of energy.
The only assumptions I am making while doing this calculations are approximately how long a user stays on that website( which is 5 seconds for Google and yahoo and 2 minutes for Youtube). Also I am using calculations about Google, shown in my previous post, as reference. I made one more assumption there, about the total number of LCDs in the world to be approximately 20%. LCDs are far more prevalent in USA and Europe, but still most of the remaining world is using good old CRTS.
Doing similar analysis for MSN.com and Myspace.com, we get the following.
MSN.com – 30% reach,8 pages per user, so white-on-screen index is almost twice of that of Google, so if they switch, they will save about 30 MW.
Myspace has reach about 5%, but page view per user about 35, so white-on-screen index is about 1.5 times of that of Google, so about 22 KW of savings.
So in all total, top five websites, Yahoo, Google, MSN, Youtube and Myspace, if switch to dark page colors, will save 15 + 45 + 180 + 30 + 22 = approximately 300 MW of energy PER HOUR. If you consider the air conditioner saving factor, this saving is higher. Also my assumptions are little on conservative side, so the real savings will most likely be even higher.
In monetary terms, this amounts to saving $36,000/ hour combined saving to the total Internet user base at 12 cents/KWH. This amount is saved from going to utility company and will be available as disposable income of consumers. This savings is apart from reducing the CO2 emissions by almost 350,000 lbs (per HOUR) and all that good stuff. Because even today majority of electricity in USA and rest of the world (except a few European countries) is produced by coal fired power plants.