Amazon recently reached a deal to use waste heat from a neighbouring, non-Amazon data centre, to heat its new corporate office complex.

The agreement provides that the Westin Building Exchange, a 34-story data centre with over 60,000 square feet of managed colocation space, will vent its heat to a central plant in the Amazon tower. Waste water is then run through heat-reclaiming chillers to raise the temperature to 130°F, and that heated water is used to provide warmth to the Amazon offices through the chilly Seattle winter.

The waste heat recovery system will eventually cover five million square feet of office space, once construction on the new facility is completed. It is expected, over the course of 25 years, to save approximately 80 million kWh of electricity use by Amazon.

Reclaiming waste energy from a nearby data centre is not a unique idea. The H&M data centre in Stockholm provides waste energy directly to the city’s power grid. However, this may be the first time that an American company has struck a deal to use waste heat from a data centre that is not their own.

This project, first conceptualized more than three years ago, is part of the larger Amazon initiative toward sustainability. Last year, the company announced plans to create five new solar farms to provide power to cloud data centres. Amazon currently has six solar farms and five wind farms in operation throughout the United States, delivering a total of 2.6 million MWh to AWS data centres in Ohio and North Virginia.

The company is moving steadily toward a long-term sustainability goal of using 100% renewable energy, no small feat for an organization that holds the position of the largest public cloud provider by a large margin. The Amazon sustainability page notes that the company exceeded the goal of 40% renewable energy by the end of last year, and is on track to meet the updated goal to be powered by 50% renewable energy by the end of 2017.

Amazon also set a goal to install solar energy systems at 50 of their locations by 2020. 15 of these will be located in the U.S., with 41 MW total combined capacity.