Less energy around German city (5)
I believe the answer is:
essen
'german city' is the definition.
(city in Germany)
'less energy around' is the wordplay.
'around' indicates a hidden word.
'ESSEN' is hidden in the letters of 'less energy'.
(Other definitions for essen that I've seen before include "Krupp HQ (Ger.)" , "Main industrial city of the Ruhr" , "Industrial centre of the Ruhr" , "city in the Ruhr valley" , "European city" .)