Produces energy packing containers (7)
I believe the answer is:
creates
'produces' is the definition.
(I've seen this in another clue)
'energy packing containers' is the wordplay.
I cannot really see how this works, but
'energy' could be 'e' (physics symbol as in E=mc2) and 'e' is located in the answer.
'containers' could be 'crates' (crate is a kind of container) and 'crates' is located in the remaining letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for creates that I've seen before include "coins" , "Brings into existence" , "Complains" , "Makes" , "Produces" .)