New Charger Harvests Energy from Wi-Fi Signals

Alot of electronics put themselves into a "wait" state, a lower power state that still lets them accept some outside input, whether it's to wake up and start making coffee at a certain time, or begin a scheduled backup or just turn on at the touch of a button and be instantly available for use. Many of these states are energy efficient only in comparison to what they normally draw, and even the ones that are pretty efficient still draw a charge that adds up over time or mass quantity.

Additionaly, a lot of electronics simply by virtue of being plugged into the wall create a circuit that "bleeds" some energy, whether the device is on or not. So yeah, there is a lot of incentive to improve efficiency, especially as we migrate to electronic everything.