Abstract: A waste heat recovery system for use with an internal combustion engine, that includes a first heat exchanger and a second heat exchanger; an exhaust conduit for receiving an input of waste exhaust gas flow from the internal combustion engine; a working fluid configured to absorb thermal energy; a heat collecting circuit operatively connected to the first heat exchanger and the second heat exchanger to transfer heat energy from the waste gas exhaust flow to the working fluid. The working fluid is first directed to the second heat exchanger then directed to the first heat exchanger, the first heat exchanger being positioned upstream, with respect to the waste exhaust gas flow, of the second heat exchanger and then to an electrical generation means. The flow of the working fluid is controllable by way of a control module as is the flow of the exhaust gases, in order to optimise both generation of eletrical energy and operation of the engine.