electric company vs power company

electric company and power company both are nouns.

Word	Noun	Adjective	Verb	Adverb
electric company	Yes	No	No	No
power company	Yes	No	No	No

As nouns, electric company and power company are synonyms defined as:

electric company and power company: a public utility that provides electricity

Other synonyms of electric company include light company, power service.

electric company (noun)	power company (noun)
a public utility that provides electricity	a public utility that provides electricity