Island possibly giving us energy (8)
I believe the answer is:
guernsey
'island' is the definition.
(I've seen this before)
'possibly giving us energy' is the wordplay.
'possibly' indicates anagramming the letters.
'giving' says to put letters next to each other.
'us' next to 'energy' is 'usenergy'.
'usenergy' with letters rearranged gives 'GUERNSEY'.
(Other definitions for guernsey that I've seen before include "Lyric poem" , "Second largest Channel Island" , "Second-largest Channel Island" , "Sir Walter Scott novel" , "One of the Channel Islands" .)