Is Gmail the World's Greenest Email?

IT and consumer computer use are major worldwide contributors to carbon emissions and there's no doubt that email is responsible for more than its share of that total. And every time you send and receive email and even when you merely store email on a server you use energy.

In an OpenWeb Developer's Journal, Bob Gourley makes the argument that Gmail is the greenest email in the world. His argument is straightforward. Google does a remarkable job greening its massive data centers, using techniques such as water evaporation for cooling, and in general streamlining their electrical infrastructure. He says "They even take the Graphics Processing Units (GPUs) out of their servers to lessen energy requirements."

The result of all this is extremely energy-efficient and green data centers. The most widely accepted measurement of power usage for data centers is Power Usage Effectiveness (PUE), which is calculated by taking the total energy used by a data center, and dividing it by the energy use of IT technology in the data center. The lower the PUE the better, and the lowest PUE possible would be 1.0. That's impossible, of course, because data centers need to be lit, cooled, and so on. But the closer to 1.0, the more energy efficient the data center.

Gourley says that Google has set an eventual PUE goal of 1.1 for its data centers overall, and already, some data center are down to a 1.11 PUE rating, which is remarkable. Microsoft is also a leader in PUE, and overall, Gourley says, the global PUE average for its data centers is 1.60, which is quite good as well.

Google takes other steps to reduce the carbon footprint of its data centers, such as using renewable energy in some of them, recycling their cooling water, and so on.

All this is why he argues that Gmail is the greenest email in the world, it's powered by the greenest data centers. He also recommends Hotmail, because Microsoft's data centers are quite green as well.