noun
power-saving function; energy conservation feature
Technical term used in computing and electronics for a facility or feature that reduces power consumption.
このプリンターには節電機能がついています。
This printer has a power-saving function.
省エネ is a broader term for energy conservation in general, while 節電機能 specifically refers to a power-saving feature or function in a device.
Compound of 節電 (power saving) and 機能 (function, feature).