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.

The ORC technology is particularly suitable for the exploitation of medium-to-low enthalpy sources. It is a cost-effective solution with power outputs reaching up to 40 MWe per single generator for sources with water temperature from 100°C to 200°C or higher.

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.

Geothermal power generation Rankine cycles require an organic-based working fluid with a lower boiling point than water, and are thus often used with lower temperature geothermal resources. The four major pieces of the Rankine cycle include the boiler, turbine, cooling tower, and feed pump.