powerhouse vs power plant

powerhouse and power plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
powerhouse	Yes	No	No	No
power plant	Yes	No	No	No

As nouns, powerhouse and power plant are synonyms defined as:

Other synonyms of powerhouse include power station.

powerhouse (noun)	power plant (noun)
an electrical generating station	an electrical generating station
a team considered to be the best of its class
a highly energetic and indefatigable person