電源 (dengen) means “power” | MotiTan Japanese Dictionary

More examples

出かける前に、電源を切ります。de ka ke ru mae ni den gen o ki ri ma su

I turn off the power before going out.

Describes the supply of electricity that makes a machine work and the point from which that supply comes.

電気denki: Electricity in general as a form of energy used to operate devices.

電気を供給して機器を動かすもと。また、機器を動かすために供給される電力。den ki o kyō kyū shi te ki ki o ugo ka su mo to ma ta ki ki o ugo ka su ta me ni kyō kyū sa re ru den ryoku

The Sino-Japanese compound 電 (den, "electricity") + 源 (gen, "source") forms 電源 (dengen), meaning a source of electric power.

In everyday Japanese, 電源 (dengen) is more specific than English power because it connects electricity directly with a device or its source.