EVSE manufacturer WattZilla has received Energy Star certification for its WattZilla Uno, WattZilla Duo, QuadZilla, Wall Wattz and WaltZilla home and commercial charging stations – a distinction that only a handful of the hundreds of charger models on the market have earned.
Energy Star-certified chargers reduce energy waste in the modes of operation when the EVSE is not actively charging a vehicle. The Idaho National Laboratory has estimated that a typical charging station spends over 85% of its time in one of these modes, and that Energy Star-certified chargers use 40% less energy in standby mode than non-certified chargers.

All Energy Star models must also meet electrical safety requirements; something that consumers unfortunately cannot always assume is the case, especially for lower-priced models.
To earn the Energy Star label, EVSE performance must be independently certified based on testing in an EPA-recognized laboratory.
Source: WattZilla