Similar to a simple Rankine cycle, a basic organic Rankine cycle (ORC) consists of four processes: increasing pressure of the working fluid through a pump, high temperature heat addition through an evaporator, expansion of the high temperature as well as high pressure fluid through a turbine, and low temperature heat ...

The organic Rankine cycle is is similar to the Rankine steam cycle, but uses an organic fluid such as refrigerants and hydrocarbons instead of water as the working fluid. The ordinary Rankine cycle uses thermal power to convert water to steam, which expands through a turbine in order to generate electricity.

Ormat's REG system captures waste heat to heat the Organic working fluid (directly, or through intermediate heat media). The heated working fluid vaporizes and expands in a turbine, which is connected to a generator that produces electricity.

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.