This article relates to diesel engineering and can be used by design organizations and river fleet vessels in operation. The device of the energy-saving installation of a river vessel uses a heat pump with a high-temperature two-stage compressor and an Organic Rankine Cycle (ORC). In a two-stage compressor, the temperature of the low-boiling substance reaches 100°C. Further, this steam is condensed in the ORC condenser, while the coolant is heated to 95-98°C and the resulting coolant is distributed through a three-way valve: part of the coolant flow enters the heating object, the other part of the coolant enters the ORC evaporator through a three-way valve, where heat exchange with a low-boiling substance takes place. The resulting high-pressure steam then enters the turbine. In this case, the steam turbine is driven with a generator and electrical energy is generated. The proposed energy-saving installation can be used by river vessels during cargo operations and forced stops, during which the power plant: the main marine diesel engine, diesel generator and auxiliary boiler plant are inoperative, which leads to significant fuel savings of the ship power plant.