Introduce power to remove exhaust (7)
I believe the answer is:
deplete
'exhaust' is the definition.
(synonyms)
'introduce power to remove' is the wordplay.
I cannot really understand how this works, but
'power' could be 'p' (symbol in physics) and 'p' is found in the answer.
'remove' could be 'delete' (deleting is a kind of removing) and 'delete' is found within the remaining letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for deplete that I've seen before include "Use up resources of" , "Reduce (amount of supplies etc)" , "Reduce the number of" , "Use up, exhaust" , "Spend" .)