Is the cloud really as green or cost-friendly as widely thought?

More power efficient?

There is, however, an oft-touted benefit of using the cloud for data storage, and that is power savings. Broadcasters are only now becoming aware of the importance of controlling power costs. Moving forward, technical managers can expect federal, state and local government bureaucrats to increasingly drive companies to use less electricity. One proposed way to reduce electrical costs is to move large-scale data storage off-site to a server farm. A huge server farm may be more efficient, have newer servers consuming less power and operate with lower costs than can a local production or broadcast house — right? Cloud storage providers may tell you so, but the real answer requires a bit of investigation. Let’s look at a real-world example.

In July 2011, the General Services Administration (GSA) announced it was the first federal agency to completely migrate its e-mail system to the cloud. The company overseeing the project, Unisys, claims to have completed the move of 17,000 employees to Google Apps for Government. The entire system now runs on Google’s cloudbased storage and email system. The conversion process required just more than a year. According to Google, that project saved the GSA 93 percent on GSA’s annual server energy costs. Google claims GSA’s annual electrical operational costs dropped from $307,400 to only $22,000. (See Table 1.)

With regards to the GSA project, Google SVP for technical infrastructure, Urs Hoelzle, wrote, “Last year, we crunched the numbers and found that Gmail is up to 80x more energyefficient than running traditional inhouse email … Our results show that a typical organization can achieve energy savings of about 65-85% by migrating to Google Apps …

“We found that the GSA was able to reduce server energy consumption by nearly 90% and carbon emissions by 85%. That means the GSA will save an estimated $285,000 annually on energy costs alone, a 93% cost reduction.”

Not so fast, Hoelzel, says energy expert and GreenMonk blog writer Tom Raferty. The truth may not be so simple, and statistics fog may hide some other important considerations.

First, the GSA opted to farm out all computing to Google. The agency choose to not update its own servers and data centers. However, according to Raftery, a 30-percent improvement in server efficiency could have been had by simply replacing five-year-old server technology with the latest versions. Second, what is entirely missing from the above Google calculation is the cost of data transfer. For media applications, moving large files up to a cloud and down again involves three things: personnel time (transfer wait), electrical power for the local desktop/ laptop, and switches and maintaining sufficient storage in the cloud. As we’ll see, for applications that require repeated operator interaction with the data, transfer power costs are not insignificant.