EnerBLOG

The internet is abuzz with the results from a report by a Harvard physicist showing that a typical Google search generates ~7 grams of carbon dioxide (something the search giant disputes). But the fact that Google owns data centers full of servers that consume electricity, and consequently contribute to greenhouse gas emissions, shouldn’t come as a surprise to anyone.

However, the increasing focus on “cloud” computing and its reliance on such server farms raises an important question - how will expanded server-based computing affect overall power consumption?

So-called cloud computing refers to systems and applications which utilize data storage and processing power at large server farms rather than on personal computers. The vision is that rather than utilizing local resources, any computer (or device) with an internet connection, can access all the applications and data that are needed. Examples of “cloud” computing include web-based email services like Gmail and word-processing applications like Google Docs. Both Gmail and Google Docs depend on Google’s server farms and require minimal system resources from your local system. A search for servers or hard drives on Amazon.com will now even lead you to an option to simply purchase computing/storage access, Amazon Web Services, rather than build the infrastructure yourself.

A cloud-based future would potentially allow for users to own simple, small, and efficient computers - if all the processing and storage takes place on server farms, there is no need for power-hungry CPU’s, large local hard drives, and cooling fans within each person’s computer. Your computer would simply be a “gateway” to the internet and the greater “cloud.” This trend is plowing ahead steadily. Just look at the ubiquity of “netbooks” at this year’s Consumer Electronics Show. Recognizing that people are increasingly relying on the cloud for email and other services which once utilized local system resources, manufacturers are churning out these low-cost, bite-size laptops with minimal processing power and storage capabilities (and consequently reduced power requirements). As consumers continue to adopt smartphones, reliance on the cloud will also increase - server farms are the backend for the Apple iPhone’s MobileMe service and all of the applications on phones utilizing Google’s “Android” OS.

If we all start to depend more on the cloud and switch to devices like netbooks, the electric meters in our homes and businesses will show a drop in consumption, but in reality, that consumption is being transposed to another location. However, that isn’t necessarily a bad thing. Let’s examine the power requirements of typical laptops and desktops vs. those of servers in data centers:

The processing power of today’s CPUs has already allowed for manufacturer’s to build less power-hungry machines: a big, hulking, tower system is no longer needed to provide sufficient levels of performance. Laptops have already surpassed desktops in sales, resulting in serious gains in efficiency as they use 20-90 Watts compared to desktops that consume on average a few hundred watts, and as much as 750-1000 watts in some high-end gaming machines. Even desktops are becoming more efficient as they utilize laptop internals - just look at the Apple’s Mac Mini, Dell’s Studio Hybrid, and Shuttle’s XPC. But, are such systems still wasteful compared to the servers that comprise the cloud?

A recent report from Faronics notes that “The energy used by 1,000 workstations in one year is equivalent to 880 barrels of oil, or 43,180 gallons of gasoline. It results in the release of 380 tons of CO2 into the atmosphere and the creation of 130 tons of landfill waste. And, assuming those 1,000 computers are always on, this energy costs more than $90,000.” What if instead of 1,000 desktop computers a business utilized 1,000 “thin-clients” that simply provided access to a server-based solution? A recent study from Hewlett Packard / Forrester Research sought to answer this question. It estimated the power consumption of desktop thin-clients to be in the range of 6-50 watts, about in line with an laptop computer. When examining the power consumption of the thin-clients AND the server infrastructure required to support them, HP/Forrester found that the server-based solution could be conservatively estimated to reduce power consumption, and CO2 emissions, by about 1/4.

How is this possible? Server farms don’t just use energy-efficient servers, they also utilize virtualization to maximize the amount of computing power from a certain amount of hardware. While a data-center may be power hungry as a whole, when viewed from a per-user standpoint, it’s significantly more efficient than the locally-based alternative.

In short, don’t worry about the seven grams of CO2 generated by your Google search. In fact, do the world a favor: buy a power-sipping netbook and use Google Apps for all your computing needs.