Dig out study describing energy record (6)
I believe the answer is:
deepen
'dig out' is the definition.
(thesaurus)
'study describing energy record' is the wordplay.
'study' becomes 'den' (I've seen this before).
'describing' is an insertion indicator (describe can mean to form the outline of).
'energy' becomes 'e' (physics symbol as in E=mc2).
'record' becomes 'ep'.
'e'+'ep'='eep'
'den' placed around 'eep' is 'DEEPEN'.
(Other definitions for deepen that I've seen before include "make room for more water" , "Intensify" , "Get stronger" , "Go lower" , "To grow" .)