Google’s major data centres are supported by at least 50 megawatts of electric power, with some estimates ranging as high as 103 megawatts - which is what Harpers magazine guesses is the power load for Google’s data centre in The Dalles, Oregon. We suspect that estimate is slightly high, as it assumes 500 watts per square foot across the total footprint of the facility – which includes both technical and non-technical space. By any measure, Google uses a boatload of power. The company has sought to avoid disclosing its power usage in its data centres. Prior to Google’s announcement of its Pryor, Oklahoma project, state legislators passed a law exempting municipal power companies from the requirement to report the amount of power used by their largest industrial customers. There are other data centre complexes that use more power than Google’s facilities. Digital Realty Trust has a facility in Chicago that has a 100 megawatt power feed, and a data centre campus in Ashburn, Virginia that is wired for 225 megawatts.