Energy-Efficient Ethernet

[7] According to a researcher at the Lawrence Berkeley Laboratory, Energy-Efficient Ethernet can potentially save an estimated US$450 million a year in energy costs in the US.

In Fast Ethernet and faster links, constant and significant energy is used by the physical layer as transmitters are active regardless of whether data is being sent.

The data link is considered to be always operational, as the receive signal circuit remains active even when the transmit path is in sleep mode.

First, it detects link status, allowing each port on the switch to power down into a standby mode when a connected device, such as a computer, is not active.

[6] In April 2008, the term was used for switches, and, in July 2008, used with wireless routers that featured user-selectable off periods for Wi-Fi to further reduce energy consumption.

[11] Projected power savings of up to 80 percent were predicted using Green Ethernet switches,[12] translating into a longer product life due to reduced heat.