The Organic Rankine Cycle's principle is based on a turbogenerator working as a conventional steam turbine to transform thermal energy into mechanical energy and finally into electric energy through an electrical generator.

ORCs operate on low temperatures and low pressures with comparative to conventional Rankine Cycles. Therefore, organic fluids or refrigerants can be used as the working fluids for ORC applications, instead of water, which is more suitable for high-pressure and high-temperature applications.

Steam Rankine cycle is known as one of the main power-generating cycles, which consists of four key devices, namely a boiler (heat exchanger), a steam turbine, a condenser (heat exchanger), and a pump, as illustrated in Fig.

It can be applied to heat and power plants (for example a small scale cogeneration plant on a domestic water heater), or to industrial and farming processes such as organic products fermentation, hot exhausts from ovens or furnaces (e.g. lime and cement kilns), flue-gas condensation, exhaust gases from vehicles, ...