Energy and the Internet

There's been a lot of debate lately about the growing amount of energy needed to power the Internet, and we wanted to weigh in on the discussion. A few months ago, I first blogged about the about amount of energy used in one Google search. Our engineers crunched the numbers and found that an average query uses about 1 kJ of energy and emits about 0.2 grams of carbon dioxide. But those raw numbers don't really put the environmental impact of searching the Internet into perspective. To add some context, below is data about the C02 impact of some everyday activities and items compared to Google searching:

Activity	Google Searches
CO2 emissions of an average daily newspaper (PDF) (100% recycled paper)	850
A glass of orange juice	1,050
One load of dishes in an EnergyStar dishwasher (PDF)	5,100
A five mile trip in the average U.S. automobile	10,000
A cheeseburger	15,000
Electricity consumed by the average U.S. household in one month	3,100,000

We work hard to provide our users with the fastest products using the least amount of energy. We have a team of dedicated engineers focused on designing and building the most efficient data centers in the world. In fact, through efficiency innovations, we have managed to cut energy usage in our data centers by over 50 percent, so we're using less than half the energy to run our data centers as the industry average. This efficiency means that in the time it takes to do a Google search, your own personal computer will likely use more energy than we will use to answer your query.

And the energy used by computers is growing; people are more plugged-in today than ever before in history. There are more than one billion PCs and laptops currently in use, and that number is expected to grow to four billion by 2020. We've got cell phones, PDAs, iPods, and GPS devices — not to mention the data centers that store all of our digital information "in the cloud." The electricity needed to run all of our computers, gadgets, and gizmos is growing and now accounts for half of all ICT emissions. (ICT stands for "information and communications technology.")

Although the amount of energy used to power ICT is growing, it's important to measure all of the ways information technology helps us save energy too. A study by The Climate Group, in fact, shows that ICT emissions pay for themselves (PDF) (and then some) by enabling significant reductions in emissions by other sectors of the economy. After all, it's much more efficient to move electrons than to move atoms. "Virtual" tools like email, video-conferencing, and search engines replace more carbon-intensive activities like snail mail, business travel, and driving.

We can still make progress at improving computing efficiency across the industry, however, and Google is committed to doing so. In 2007 we co-founded the Climate Savers Computing Initiative, a non-profit organization committed to reducing global CO2 emissions from the operation of computers by 54 million tons a year by 2010. Check out their website for more information on how you can reduce the environmental impact of your own computer use.

Update 7/16/09: Google's Q2 2009 data center efficiency measurements are now available here. 

Posted by Urs Hölzle, Senior Vice President, Operations