Usual Rankine cycles are thermodynamic cycles that employ water as a working fluid to produce electric power from thermal sources. In Organic Rankine cycles, by contrast, water is substituted by molecularly complex organic compounds. Since the vaporization temperature of these kinds of fluids is lower than that of water at atmospheric pressure, low-to-medium temperature sources can be exploited allowing for heat recovery, for example, from biomass combustion, industrial waste heat, or geothermal heat. For these reasons, ORC technology belongs to the class of renewable energies.