Google has revealed that the company is set be 100% powered by renewable energy ...

A new blog from Google has revealed that the company is set be 100% powered by renewable energy this year. Over the last seven years, the company has been gradually signing long-term contracts to directly purchase enough renewable energy to power its global server farms. Today, Google claims to be the largest corporate purchaser of renewable power with contracts that add up to around 2.6 gigawatts (2,600 megawatts) of wind and solar energy.

The reason Google decided to start purchasing renewable energy was to reduce its carbon footprint and help combat climate change. But, over time, the decision has made more business sense as renewable prices have fallen. As powering the corporation's huge global network of data centres is one of the largest components in the company’s operating costs, the stability of the contract prices also helps it plan ahead accurately. 

Of course providing energy is one thing, but it is better not to need all that energy in the first place. The blog also claims that work from the company’s engineers now means that Google’s data centres are 50% more energy efficient than the industry average. The company has undertaken a number of initiatives to reduce the power required to operate data centres. It has pioneered a method of running the cold aisle at 80^oF instead of the standard 70^oF, meaning that there is less cooling required overall. Google also free cooling techniques to keep temperatures stable, reducing the time that active cooling is required, and even then, the fans are designed to only spin as fast as required to keep the temperature within limits.

On the power design side, the company employs highly energy-efficient servers that are designed to use little energy in sleep mode. Google claims that it is typical for a server to waste up to 33% of the supplied energy before it even reaches the computational circuits, and that is due to the nature of power conversion and distribution. Taking the AC voltage to the lower DC voltages that the servers requires takes several stages and is often wasteful. Regulating the DC voltage wastes more. Google has implemented an architecture that only requires one intermediate conversion stage, which the company estimates saves 500 kWh annually.