For energy, helping to provide a great deal (13)
I believe the answer is:
proliferation
'a great deal' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'for energy helping' is the wordplay.
'for' becomes 'pro' (as in being 'pro' something).
'energy' becomes 'life' (I've seen this in another clue).
'helping' becomes 'ration' (a ration is a serving or helping).
'pro'+'life'+'ration'='PROLIFERATION'
'to provide' is the link.
Can you help me to learn more?
(Other definitions for proliferation that I've seen before include "Increase in numbers" , "Increase (of nuclear weapons)" .)