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.

Organic Rankine cycle (ORC) machines are used to convert low-temperature heat resources into power. Examples include systems making use of waste heat in a cogeneration system, low temperature geothermal electricity generation, solar ponds, and potentially OTEC.

The four main components of the Rankine cycle are the water pump, boiler, turbine, and condenser. There are four main stages to the Rankine cycle. Compression, heating, expansion, and condensation of the working fluid. The Rankine cycle can be represented by a pressure-volume diagram for each stage.