Powerhouse (6)
I believe the answer is:
dynamo
'powerhouse' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for dynamo that I've seen before include "Generator (sometimes 'human'?)" , "Monday (anag)" , "Converter of mechanical to electrical energy" , "Electricity generator or energetic person" , "Electricity generator or vigorous person" .)