The Rankine cycle is an idealized thermodynamic cycle describing the process by which certain heat engines, such as steam turbines or reciprocating steam engines, allow mechanical work to be extracted from a fluid as it moves between a heat source and heat sink.

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 Rankine cycle is an idealized thermodynamic cycle of a heat engine that converts heat into mechanical work while undergoing phase change. The thermal efficiency equals 1 minus the ratio of the low-to-high pressures to the power of 1 minus the reciprocal of the heat capacity ratio.

The organic Rankine cycle can be used in the solar parabolic trough technology in place of the usual steam Rankine cycle. The ORC allows electricity generation at lower capacities and lower collector temperature, and hence the possibility for low-cost, small scale decentralized CSP units.