The invention relates to a system (12) for the recovery of energy from exhaust gases from at least one turboshaft engine, comprising a turbine (34) fitted rotatably around a recovery shaft (40), adapted to bleed off at least a part (14) of the exhaust gases, known as bleed gases (14), and to expand said bleed gases (14) to become expanded gases (42) at a pressure below atmospheric pressure, a first heat exchanger (44), adapted to use a cold source (45) to cool said expanded gases (42) to become cooled gases (46), and a compressor (36) fitted rotatably around said recovery shaft (40), adapted to compress said cooled gases (46) to atmospheric pressure.