What is the Cloud?

How many photos do you think there are on Facebook?  500 million?  1 billion? 7 billion – one for each person on the planet? Current predictions have the number around 100 billion.  That is 200 million uploads per day.  Where do you think 100 billion photos are stored?  What about all those Gmails, Tweets, or blog posts?  They reside on the cloud, of course.  Putting it on the cloud is the cool thing to do these days.  Our photos, emails, bank statements, car payments, books, movies, video games, and our favorite YouTube videos are all on the cloud.  All this good stuff isn’t stuffed into our iPhones…so where is it?

The cloud is just a fancy name for a computer that can be accessed to retrieve information. A single computer cannot hold 100 billion Facebook photos, but thousands can.  Place thousands of computers in a warehouse with no windows, turn them all on, and we have a place to put your summer vacation photo album; likes, tags, and comments included.  This windowless warehouse full of running computers is called a data center.  Data centers are full of thousands of running computers very similar to the one that you have at home.  Data centers are the cloud.

Data centers can be located just about anywhere.  There is a big one right in downtown San Francisco, although it is not obvious.  There is a place in Silicon Valley where you can throw a stone at four without moving.  Facebook just opened a new state of the art data center in the small town of Prineville, Oregon. All of these facilities are highly secure and operate 24/7.  Even just a minute of downtown can cost a company millions of dollars.  Besides, how frustrating is it when we go to check our bank statements but we can’t because of online maintenance.  Since so much of our daily lives take place online and in the cloud, great care is taken to ensure that data centers never ever shut down.  In order for this to be possible the highest level of security and uninterrupted electrical supply is required.  I want to focus on the power supply for data centers because the amount of electricity required to operate them is enormous.

Typical data centers draw around 1 – 5 megawatts (MW) of electricity.  The largest require 20 MW of electricity.  For reference, 20 MW is enough energy to power ~16,000 homes.  The most recent study completed by Johnathan Koomey in 2011 estimates data center energy use to be 2% of total US electric consumption (report).  As more services migrate online and we shift to a culture of mobile computing, the more energy we will need to power our data centers.  The tech sector is growing at a rapid pace and the energy required to power it will need to keep up.   The next time you go on facebook and check your friend’s new photos, be cognizant of the fact that each photo is not a white puff in the sky, it is a little spinning disk located in a windowless warehouse consuming electricity.  Lots of electricity.


5 thoughts on “What is the Cloud?

  1. Really well written article. I will surely recommend this to anyone who doesn’t understand the concept of cloud. The figures are pretty impressive. Didn’t know that so much electricity is used. Makes sense though.
    Thanks for sharing!!

  2. Hi Dan,

    Great article, I have a question, according to Emerson’s article in 2011, there are more than 500,000 data centres worldwide. When I look at the world data centre maps (http://www.datacentermap.com/datacenters.html), there are only 3000 data centre’s located on the map. Do you know by any chance any map that shows all the data centres in the world? I am doing a research in school and I have a hard time finding such map. Thanks!


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