Greenpeace maintains that despite a proliferation of industry-created metrics for sustainability, none answer the questions: How much dirty energy is being used, and which companies are choosing Green energy to power the Cloud?

The organisation examined a representative sample of each company's most recent infrastructure investments, looking at the estimated size of electricity demand and the amount of renewable energy being used to power each facility. It contacted each company, requesting information on the data centres, as well as information about infrastructure siting and mitigation efforts.

"We expect these companies to play a pivotal role in ensuring we move to clean, safe renewable energy systems and avoid future disasters like Fukushima," Greenpeace IT policy analyst, Gary Cook, says.

"But the IT industry's failure to disclose basic information on its rapidly growing energy footprint has hidden a continued reliance on 19th century dirty coal power to power its 21st century infrastructure."View in a larger map

One of Greenpeace's gripes is that too often the IT industry equates sustainability with energy efficiency -- an area that has seen good progress in recent years. The problem is that any gains in efficiency can be quickly negated by increased growth. And we are all too aware of the near exponential rise in data volumes over the coming years. The other issue is a lack of transparency. When Amazon Web Services reviewed Greenpeace's power demand estimates, for example, it responded that the figures were not correct but did not provide alternative figures. Similarly for Google, which indicated the Greenpeace estimates had substantially exceeded Google's current electricity demand, but did not provide additional information.