The proliferation of electronic devices and appliances in homes
and their impact on the efficiency and cost of smart-grid
electrical power has given rise to a public debate over whether
Wi-Fi or ZigBee represents the most energy-efficient way to deal
with the situation.
On one side is General Electric, which argues that ZigBee is
more energy efficient than Wi-Fi. On the other side, the Wi-Fi
Alliance maintains that "Wi-Fi offers unsurpassed capabilities for
the smart grid" and that GE's recent study hailing ZigBee "is
flawed, resulting in inaccurate findings." The Wi-Fi Alliance on
Monday released its rejoinder to GE's early December white
paper.
In its report, a team of GE engineers and technicians from the
appliances and lighting units studied Wi-Fi, Bluetooth, and ZigBee
solutions to determine which of the existing technologies would
best minimize the energy impact of home energy networks. The GE
team dismissed Bluetooth quickly, arguing that its limited range
made it unsuitable for home networking of appliances and other
products.
In comparing Wi-Fi with ZigBee, GE said it found that components
for ZigBee-based devices were less expensive than Wi-Fi components.
In addition, the GE investigators said ZigBee's mesh networking
capability resulted in energy savings as did other features of the
ZigBee standard.
The GE team argued that overall home network energy cost savings
for ZigBee over Wi-Fi would result in theoretical annual savings of
USD 315 million based on an assumed population of 750 million
devices.
In its release rebutting the GE findings, the Wi-Fi Alliance
said the GE investigators based their findings in part on older,
less efficient Wi-Fi technology that has been upgraded since the GE
report was issued.
"Because the evaluation was based on old technologies," said the
Wi-Fi Alliance, "its conclusions present an inaccurate
characterization of the energy efficiency of both ZigBee and Wi-Fi
technologies and cannot be used to draw generalized conclusions
about the state of smart grid communications technology today."
The Wi-Fi Alliance noted that more recent Wi-Fi releases, including
802.11n, are more energy-efficient than the older Wi-Fi technology
examined by the GE team.