Last year Google estimated that Gmail is up to 80 times more energy-efficient than running traditional in-house email service. Now the company has calculated that a typical organisation can achieve energy savings of 65-85% by migrating to Google Apps as a whole – documents, spreadsheets, email and other applications.
Google points to three main energy impacts from the use of a Google apps:
A typical organisation has a lot more servers than it needs—for backup, failures and spikes in demand. Because servers draw nearly the same amount of energy regardless of how busy they are, this results in a large waste of energy. Cloud-based service providers like Google aggregate demand across thousands of people, substantially increasing how much servers are used, so fewer are needed. The net result is a 70-90% reduction in the direct energy used.
In addition, almost every unit of energy that a server consumes ends up as heat, causing air-conditioning systems to work harder than they otherwise would. In many situations each watt of direct power consumption needs 1.5 additional watts of cooling. But Google’s data centres need just 0.13 watts of cooling for each watt of direct power. The company estimates that overall, using Google apps will see energy costs for server cooling decrease by 70–90%.
But these savings are not free. Using cloud-based services results in some additional energy consumption from the use of Google servers and an increase in traffic on the Internet. The analysis suggests a net increase of 2–3% in energy consumption for office computing migrating to the cloud.
Google quotes research from the Carbon Disclosure Project that found that by migrating to the cloud, companies with over $1bn in revenues in the US and Europe could achieve substantial reductions in energy costs and carbon emissions by 2020. UK companies would save £1.2bn and more than 9.2 million metric tonnes of CO2.
Google also points to the experience of the US General Services Administration (GSA), which recently switched 17,000 users to Google Apps for Government. The GSA was able to reduce server energy consumption by nearly 90% and carbon emissions by 85%, saving 93% of the energy costs - $285,000 annually.
There’s more detail in the white paper (see the link above), but Google’s findings do further substantiate the carbon emissions benefits of using cloud computing. (Microsoft conducted a similar exercise that found that, for large deployments, the company’s cloud solutions can reduce energy use and carbon emissions by more than 30% for large deployments and 90% for small deployments).
But these are the major, on-line resource companies that have a lot to gain from making their data centres as efficient as possible. Not all IT services providers will have such efficient facilities, so the cloud/non-cloud benefit will not always be so stark. If reduced emissions is the reason for adopting cloud services, then it’s always worth checking.