As the Internet of things grows to encompass billions of devices, its power usage will require novel technologies for improving efficiency.

Source: www.technologyreview.com

From IEA study: … the electricity demand of networked devices around the world in 2008—420 terawatt-hours—was equal to that of France; in 2013 the demand surpassed that of Canada, reaching 616 terawatt-hours. By 2025, the report projects, networked devices will account for 6 percent of global electricity demand at 1,140 terawatt-hours. As much as 80 percent of that demand will be used just to maintain a network connection, keeping devices ready and waiting."