NOVELTY - The system (1000) has a series of one-way pressure/vacuum (PV) valves (202, 302, 308) for keeping flow of fluid (20) in conduits (10) along same direction. An electric generator is interoperably connected to a turbo (214) of an expansion cycle subsystem (210). The generator is interoperably connected to an electric motor being used for auxiliary direct propulsion for an internal combustion engine of a vehicle, where an energy capture subsystem (100), the expansion cycle subsystem, a condenser cycle subsystem (250) and a reservoir subsystem (300) are interconnected by the conduits.    USE - Energy retrieval system i.e. self-contained thermodynamic energy retrieval system, for an internal combustion engine of a vehicle e.g. self propelled mobile vehicle such as automobile/car. Can also be used for a ship, boat, train, lorry, bus and a streetcar, and for habitable structures i.e. buildings.    ADVANTAGE - The system is designed such that a battery is interoperably connected to the electric motor that assists in propelling the mobile vehicle when a heat source e.g. solar panel, does not generate heat. The system is designed such that the fluid is not hazardous to human health if the fluid is exposed to humans. The system allows heat energy created by the engine to be converted to other forms of energy e.g. kinetic energy, that can reduce workload on the engine to make total automobile to be more efficient and reduce fuel required to run the automobile with the engine that produces heat during operation regardless of engine size or type of the vehicle to which the engine is tasked with powering. The system allows the engine to be automatically started when battery power is not sufficient and allows the engine to take over propulsion duties of the automobile when the heat resulting from the internal combustion recharges the battery and provides some propulsion of the vehicle. The system allows the engine to operate at considerably higher temperatures or full operating temperature such that the system can be fully operational and quicker. The system creates cold compressed air for keeping temperatures in combustion chambers of the engine at normal temperatures so as to reduce pollution from the engine. The system provides heat required to operate a cooling system at considerable less cost.    DETAILED DESCRIPTION - The fluid is selected from a group consisting of air, water, ammonia, helium, common air-conditioning refrigerants and noble gases e.g. neon, argon, krypton, xenon and radon.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic block diagram of an energy retrieval system.    Conduits (10)    Fluid (20)    Energy capture subsystem (100)    Heat source (102)    Energy extraction Subsystem (200)    One-way PV valves (202, 302, 308)    Expansion cycle subsystem (210)    Turbo (214)    Condenser cycle subsystem (250)    Reservoir subsystem (300)    Energy retrieval system (1000)