In an effort to hold itself accountable to its sustainability goals, Google has developed a new publicly-available metric that provides an indication of exactly how clean the company's cloud regions are around the world.
Called the carbon-free energy percentage (CFE%), the number reflects the average mix of carbon-free and fossil-fuel energy that is used to power Google's data centers in each region.
The higher the percentage, the more carbon-free power was used in the mix; in other words, a high CFE% is indicative of a "greener" region. On the other hand, a lower-scoring region has more hours in the year that require fossil-fuel based energy.
London's CFE%, for instance, is of 54%; this means that data center applications in the region are, on average, running on carbon-free energy just over half of the time.
The CFE% was calculated for every hour in Google's cloud regions, based on how much carbon-free energy was produced on the local grid at any given moment, as well as the amount of that renewable energy that was purchased by the Search giant. Hourly averages were aggregated for each region and are now available online and in a GitHub repository.