절전이 · 절전을
saving electricity, power saving
Example
여름에는 절전을 위해 에어컨 온도를 높이세요.
In summer, raise the air conditioner temperature to save electricity.
Word parts
절 economize+전 electricity
Literally 'economize electricity'.
Good to know
On devices you'll see 절전 모드 = power-saving or sleep mode.
Related words