Saving money by moving IT operations to the Cloud may have freed up some of your tech budget, but there’s a good chance the shift may be having a lousy impact on your “green” initiative. That’s because a recent report from the folks at Greenpeace finds that some of the most popular Cloud providers are also owners of the dirtiest Cloud services.

The Greenpeace report – “How Clean is Your Cloud” – awarded Cloud service providers with a score based on the energy efficiency of data centers and the type of energy used to power them.

Apple got lousy marks, incuding a D in energy transparency and an F in “infrastructure sitting.”

Amazon got nearly straight Fs across the board. Google had the highest scores, with an A in renewables and advocacy, and a B in energy efficiency.

The report noted that it’s tough to parse the true efficiency of so-called green data center and that metrics that many companies use, like Power Usage Effectiveness, aren’t the right ones.

Says the report:

“The engine that drives the Cloud is the data center. Data centers are the factories of the 21st century information age, containing thousands of computers that store and manage our rapidly growing collection of data for consumption at a moment’s notice.

“These cloud data centers, many of which can be seen from space, consume a tremendous amount of electricity; some consume the equivalent of nearly 180,000 homes. Unfortunately, despite the tremendous innovation they contain and the clean energy potential they possess, most IT companies are rapidly expanding without considering how their choice of energy could impact society.

“Given the energy-intensive nature of maintaining the cloud, access to significant amounts of electricity is a key factor in decisions about where to build these data centers. Since electricity plays a critical role in the cost structure of companies that use the cloud, there have been dramatic strides made in improving the energy efficiency design of the facilities and the thousands of computers that go inside.

“However, despite significant improvements in efficiency, the exponential growth in cloud computing far outstrips these energy savings. Companies must look not only at how efficiently they are consuming electricity, but also the sources of electricity that they are choosing.”

To drive home their point, the report’s authors cite this jaw-dropping comparison: “If the Cloud were a country, it would have the fifth-largest electricity demand in the world.”

Both Apple and Amazon dispute the numbers Greenpeace cited and Apple’s touting the energy efficiency of its new data facility in North Carolina.

Regardless, you’ll want to investigate how energy is supplied and managed by your Cloud provider before you sign on for services, especially if your clients and customers have policies about doing business only with environmentally conscious vendors.

Tags: Amazon, Apple, cloud, efficiency, energy, Google, green, Greenpeace, providers