Can rule out sort of energy (7)
I believe the answer is:
nuclear
'sort of energy' is the definition.
(I've seen this before)
'can rule out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'can'+'rule'='canrule'
'canrule' with letters rearranged gives 'NUCLEAR'.
(Other definitions for nuclear that I've seen before include "Relating to part of atom" , "Relating to atomic weapons" , "Relating to fission or fusion" , "Like some physics" , "Such power available" .)