Serve up dry plonk - after starting it'll provide you with energy (7)
I believe the answer is:
turbine
'it'll provide you with energy' is the definition.
'serve up dry plonk after starting' is the wordplay.
'serve up' is a reversal indicator.
'dry' becomes 'brut' (type of wine).
'plonk' becomes 'wine' (I've seen this before).
'after starting' means to remove the first letter (only the letters found after the first are used).
'brut' back-to-front is 'turb'.
'wine' with its initial letter taken off is 'ine'.
'turb'+'ine'='TURBINE'
(Other definitions for turbine that I've seen before include "Machine driven by wheel turned by flow of water or gas" , "Machine producing power when water drives a rotor, for example" , "Rotary engine" , "Power-producing machine" , "Rotary motor" .)