Mistake supplying energy to house (5)
I believe the answer is:
gaffe
'mistake' is the definition.
(a gaffe is a mistake or error)
'energy to house' is the wordplay.
'energy' becomes 'e' (physics symbol as in E=mc2).
'to' is a charade indicator (letters next to each other) (I've seen this in other clues).
'house' becomes 'gaff' (gaff can informally mean someone's house).
'e' after 'gaff' is 'GAFFE'.
'supplying' is the link.
(Other definitions for gaffe that I've seen before include "Blundering remark" , "Embarrassing blunder" , "A foolish error" , "A blunder, faux pas" , "embarrassing error" .)