The title says it: plugged into the wall (120vac), but disconnected from the MacBook Air, how much power is consumed by the power supply?

1 Answer 1


I have measured the consumed energy of an Apple MagSafe 2 60 W Power Adapter over a period of three weeks while idle.

The energy consumption drops to 0.00001 kWh per day after less than 30 minutes since the last usage.

I am confident that the MagSafe 2 45 W Power Adapter will behave the same.

Apple MagSafe 2 60 W Power Adapter

Note: Other power supplies I have do consume a measurable amount energy with no devices attached. So Apple seems to have done a really great job building these power supplies.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .