Waste energy making jam (6)
I believe the answer is:
scrape
'jam' is the definition.
(both can mean a difficult situation)
'waste energy' is the wordplay.
'waste' becomes 'scrap' (synonyms).
'energy' becomes 'e' (physics symbol as in E=mc2).
'scrap'+'e'='SCRAPE'
'making' acts as a link.
(Other definitions for scrape that I've seen before include "Clean with something sharp" , "Clean with edge of knife" , "Save with difficulty - sounds abrasive" , "What violinist does" , "Bark" .)