The Cloud Begins with Coal

Big Data, Big Networks, Big Infrastructure and Big Power.

An Overview of the Electricity Used by the Global Digital Ecosystem.

Executive Summary.

The information economy is a blue-whale economy with its energy uses mostly out of sight. Based on a mid-range estimate, the world’s Information-Communications Technologies (ICT) ecosystem uses about 1,500 TWh of electricity annually, equal to all the electric generation of Japan and Germany combined – as much electricity as was used for global illumination in 1985.  The ICT ecoystem now approaches 10% of world electricity generation.  Or in other energy terms – the zettabyte era already uses about 50% more energy than global aviation.

Reduced to personal terms, although charging up a single tablet or smart phone requires a negligible amount of energy, using either to watch an hour of video weekly consumes annually more electricity in the remote networks than two new refrigerators use in a year.  And as the world continues to electrify, migrating towards one refrigerator per household, it also evolves toward several smartphones and equivalent per person.

The growth in ICT energy demand will continue to be moderated by efficiency gains.  But the historic rate of improvement in the efficiency of underlying ICT technologies started slowing around 2005, followed almost immediately by a new era of rapid growth in global data traffic, and in particular the emergency of wireless broadband for smartphones and tablets.  The inherent nature of the mobile Internet, a key feature of the emergent Cloud architecture, requires far more energy than do wired networks.  The remarkable and recent changes in technology mean that current estimates of global ICT energy use, most of which use pre-iPhone era data, understate reality.  Trends now promise faster, not slower, growth in ICT energy use.

Future growth in electricity to power the global ICT ecosystem is anchored in just two variables, demand (how fast traffic grows), and supply (how fast technology efficiency improves):

  • As costs keep plummeting, how fast do another billion people buy smartphones and join wireless broadband networks where they will use 1,000 more data per person than they do today; how fast do another billion, or more, join the Internet at all; how fast do a trillion machines and devices join the Internet to fuel the information appetite of Big Data?
  • Can engineers invent, and companies deploy, more efficient ICT hardware faster than data traffic grows?

To estimate the amount of energy used to fuel everything that produces, stores, transports, processes and displays zettabytes of data, one must account for the energy used by:

  • Data centers that have become warehouse-scale supercomputers unlike anything in history;
  • Ubiquitous broadband wired and wireless communications networks;
  • The myriad of end-use devices from PCs to tablets and smart phones to digital TV, and,
  • The manufacturing facilities producing all the ICT hardware.

Hourly Internet traffic will soon exceed the annual traffic of the year 200.  And demand for data and bandwith and the associated infrastructure are growing rapidly not just to enable new consumer products and video, but also to drive revolutions in everything from healthcare to cars, and from factories to farms.  Historically, demand for bits has grown faster than the energy efficiency of using them.  In order for worldwide ICT electric demand to merely double in a decade, unprecedented improvements in efficiency will be needed now.

Electricity fuels the infrastructure of the world’s ICT ecosystem – the Internet, Big Data and the Cloud.  Coal is the world’s largest single current and future source of electricity.  Hence the title of this paper.

The study is available at

Partner & Fellow Blogs