Replace electricity Her Grace wasted (8)
I believe the answer is:
recharge
'replace electricity' is the definition.
(fill a device with electricity again)
'her grace wasted' is the wordplay.
'wasted' is an anagram indicator.
'her'+'grace'='hergrace'
'hergrace' is an anagram of 'RECHARGE'.
(Other definitions for recharge that I've seen before include "Pass on cost" , "Replenish power supply for, say battery" , "Provide with fresh energy (as battery)" , "Give new power" , "Top up (battery)" .)