Relief from the sun? Air conditioner energy! (6)
I believe the answer is:
solace
'relief' is the definition.
(I know that solace is a type of relief)
'sun? air conditioner energy' is the wordplay.
'sun?' becomes 'sol' (Latin for 'sun').
'air conditioner energy' becomes 'ace' (this might be a standard abbreviation which I don't know about).
'sol'+'ace'='SOLACE'
'from the' acts as a link.
Can you help me to learn more?
(Other definitions for solace that I've seen before include "Consolation, comfort" , "Kind of comfort - a close thing" , "Comfort and reassurance" , "console" , "Comfort in time of distress" .)