Just how green is cloud computing?

Facebook recently tweeted a statistic that gives the public a sense of how much new data enters cyberspace on a regular basis.

Over New Year's weekend, Facebook users uploaded a record 750 million photos. According to the company's count, over 100 million photos get uploaded to Facebook each day. And as more of our day-to-day computing activities migrate from hard drives to Internet servers, environmental groups are worried that the trend will result in a bigger carbon footprint.

Typically, data that is created and uploaded to websites like Facebook is stored at data centers, sometimes referred to as server farms or server clusters. Electricity keeps a majority of these data warehouses running and comfortably air-conditioned to prevent overheating, which can result in some pretty hefty energy consumption. Data centers are responsible for two percent of the world's greenhouse gas emissions, and experts expect that number to increase.

Some companies, however, point out that a growing trend towards cloud computing is making online computing more energy-efficient. Cloud computing allows users to access products and services like applications and data storage remotely. By storing and running processes on the "cloud," websites can share the resources stored on a wide network of servers, which can keep them from going idle and wasting the energy used to power them.

A study commissioned by Microsoft and conducted by IT consulting firm Accenture estimate that companies could cut energy consumption and carbon emissions by 30 percent by switching over to the cloud. And an analysis by market research and consulting firm Pike Research backed up some of these reported benefits, suggesting that data centers can reduce their energy consumption by 38 percent, according to an article in PC World magazine.

But a recent news report on the website of the PBS citizen journalism TV program Mediashift highlights some of the doubts that environmental groups like Greenpeace and other skeptics have with regard to just how green cloud computing can truly be.

"There is a lot more proof that needs to be put in place to show that the cloud can be green," said Simon Mingay, Gartner's vice president of research. In collaboration with the World Wildlife Fund, his firm recently released a study examining the carbon footprint of the ICT industry. "Whilst we all recognize the potential of it, I haven't seen anything yet that convinces me that that's a reality today," Mingay said.

The report continues to say:

Environmentalists are concerned about the industry's apparent confusion with the difference between efficiency and sustainability. Companies "need to recognize that energy efficient is not 'green' on its own, and is no longer enough. NGOs, and increasingly customers will demand more," Mingay wrote in a post on Gartner's blog.

Greenpeace blogger Jodie Van Horn explained why her NGO is so concerned about this confusion: "A highly efficient data center powered by coal destroys the planet, it just does so more slowly than one lacking in state-of-the-art efficiencies."

Greenpeace is hardly joking around. Here's a video it made that's critical about Facebook:

Although the critics haven't shown any sign of letting up, they do bring up an interesting question. While energy efficiency is a worthy goal to strive for, can it still be considered a step towards sustainability even as the technology becomes more ubiquitous?

Some companies have responded to these types of concerns by going a step further and building data centers that tap into alternative energy as a greener way to power their severs. Last year, Hewlett-Packard built a data center in Billingham, a town off the northeast shore of England, so that the addition of a fan-based cooling system can take advantage of the high winds coming in from the North Sea. And Yahoo has opened a data facility designed to work similarly to a chicken coop, allowing hot air to vent off the top of the housing.

(To learn more, check out SmartPlanet editor Andrew Nusca's report on HP and Yahoo's green data centers.)

Such efforts won't entirely ease the concerns of some environmental groups, but they do suggest that as the market for cloud computing grows, alternative energy solutions will likely play a much larger role.

Photo: Yahoo!

This post was originally published on Smartplanet.com