power grid vs powerhouse

power grid and powerhouse both are nouns.

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

power grid (noun)	powerhouse (noun)
a system of high tension cables by which electrical power is distributed throughout a region	an electrical generating station
	a team considered to be the best of its class
	a highly energetic and indefatigable person