Google's energy-saving is explained a little in the release of a white paper on how neural networks are helping it in its quest.
It’s no secret that we’re obsessed with saving energy. For over a decade we’ve been designing and building data centers that use half the energy of a typical data center, and we’re always looking for ways to reduce our energy use even further. In our pursuit of extreme efficiency, we’ve hit upon a new tool: machine learning. Today we’re releasing a white paper (PDF) on how we’re using neural networks to optimize data center operations and drive our energy use to new lows. Google Releases White Paper on How It's Using Neural Networks To Optimize Its Data Centers [googleblog.blogspot.com]