Cloud not always greener than on-premise - study

Well-run on-site server rooms could be more energy efficient than "brown clouds", report finds

Cloud computing may not be as green as proponents would have you believe, a new study suggests.

Research by WSP Environment & Energy and the Natural Resource Defense Council has found that cloud is not always a more energy- and carbon-efficient option than on-premise, despite it commonly being sold on a green agenda.

WSP director David Symons said: "There are many reasons for moving to cloud computing, but a company choosing to do so for pure energy-efficiency reasons needs to look closely at their whole IT set up as well as those of third-party offerings.

"Not all clouds are created equal. An on-site server room that is run with energy-efficiency best practices may be a greener alternative to a ‘brown cloud'."

The research examined best practice, average and worst-case scenarios for five set-ups: on-premise with no virtualisation; colocation with no virtualisation; on-premise with virtualisation; private cloud; and public cloud.

Running a productivity application generally becomes more efficient as you move through those options, but it will depend on the carbon emission factor of the electricity used by the datacentre, as well as its energy efficiency and the capacity at which it is running.

A typical user of an on-site server with no virtualisation will emit about 46kg of CO2 per year in the worst-case scenario, Symons told ChannelWeb. The equivalent figure for a person using a public cloud conforming to best practices is just 2kg.

However, there will be scenarios where public cloud is less energy efficient than on-premise with no virtualisation, said Symons.

"If you are storing data on the public cloud but using a public cloud provider whose servers are not that efficient, are not well used and use electricity from higher-carbon-emitting sources, there could be scenarios where running your own servers is a greener option," he said.

Symons gave the example of a UK firm using a cloud provider in Colorado. Due to the fact it uses more coal, that datacentre will emit twice as much carbon per unit of electricity as one in the UK, he said.

"So, if nothing else, from a carbon perspective it needs to be twice as efficient from a PUE [power usage effectiveness] and utilisation perspective as the one in the UK," said Symons.

The research comes as the latest blow for fans of the fluffy style of IT after analyst Canalys warned last week that the hype surrounding cloud computing is on the wane.

According to Steve Brazier, chief executive of analyst Canalys, the cloud buzz is beginning to subside amid growing recognition that it may be the right move only for options that target consumers, are new, or manage traffic.

"But it makes no sense to take IT that already works and move it into the cloud, just for the sake of it," Brazier said.