In the last few years, devices based on ZigBee, the wireless communications technology, have gained momentum in the energy sector.
Some U.S. utilities have deployed ZigBee-enabled smart meters, and have encouraged customers to purchase home area network (HAN) devices that can connect to such smart meters for improved energy management.
Source:
http://smartgrid.testing-blog.com/2013/04/19/zigbee-smart-energy-devices-to-pass-219-million-units-by-2020/#more-31517
