Sort of power my generation endlessly put out without carbon (6,6)
I believe the answer is:
atomic energy
'sort of power' is the definition.
'my generation endlessly put out without carbon' is the wordplay.
'endlessly' means to remove the last letter.
'put out' is an anagram indicator.
'without' means one lot of letters goes inside another ('without' can be similar in meaning to 'outside').
'carbon' becomes 'c' (C is the chemical symbol for carbon).
'my'+'generation'='mygeneration'
'mygeneration' with its final letter taken away is 'mygeneratio'.
'mygeneratio' is an anagram of 'atomienergy'.
'atomienergy' placed around 'c' is 'ATOMIC ENERGY'.
(Other definitions for atomic energy that I've seen before include "Power from fission or fusion" , "Nuclear power" .)