Focus on low carbon: Appliances still consume electricity after being turned off?

Leung Yiu-cheung, a professor in the Department of Mechanical Engineering at the University of Hong Kong, provided data from a recent study that confirmed that some electrical appliances continue to consume power even after being turned off without unplugging. According to its research data, these household appliances that still consume electricity after switching off consume anywhere from 2 to 24 watts per hour, which means that every Hong Kong household can save nearly 30 KWH of electricity a month if it unplugged.

According to their tests, desktop computers consume an average of 43.06 watts per hour when they are on standby, and 12.34 watts per hour if they are not unplugged after they are turned off. The power consumption of audio equipment, electric fan and TV decoder (set-top box) without unplugged after shutdown is 3.91 watts, 3.38 watts and 1.56 watts respectively. The copier consumes an average of 116.7 watts per hour when it is in standby mode, and 24.8 watts per hour when it is turned off.

Why do some electrical appliances still consume power if they are not unplugged after shutdown? Liang Yaochang explained that there are transformers in general electrical appliances, used as circuit transmission, and connected wires and plugs, unless the power is directly cut off, such as pulling out the plug or turning off the wire switch, by turning off the switch of the electrical appliance, some components of the electrical appliance may still be in a standby state, so it will continue to consume power.