ORC: How it works In a typical ORC design, a thermal energy source feeds an evaporator to drive an expander or “reverse compressor”, which in turn generates the electricity. The provider of the heat can be natural, such as in the case of geothermal energy, or waste heat from any number of industrial waste heat sources.

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.

The working principle of the organic Rankine cycle is the same as that of the Rankine cycle: the working fluid is pumped to a boiler where it is evaporated, passed through an expansion device (turbine, screw, scroll, or other expander), and then through a condenser heat exchanger where it is finally re-condensed.

ORC technologies operate by transferring heat from the source through an evaporator to boil a fluid and create vapor that is expanded across a turbine or other work extraction device. This creates shaft power that can be easily turned into electrical power through a generator.