Organic Rankine Cycles (ORC) are systems that can effectively recover low-grade heat for electric power generation. For ORC to be a viable technology, it should operate safely and efficiently under variable operating conditions due to exogenous and operating specifications changes.

A system that uses the Rankine cycle has four parts: a pump, a boiler, a turbine and a condenser. The pump's job is to deliver liquid to the boiler. The boiler's job is to heat the liquid and turn it to vapor. The vapor is then used to power a turbine.

This process was developed in 1859 by Scottish engineer William J.M. Rankine. This is a thermodynamic cycle which converts heat into mechanical energy—which usually gets transformed into electricity by electrical generation.

The Rankine cycle is named after William John Macquorn Rankine, a Scottish polymath professor at Glasgow University. Heat energy is supplied to the system via a boiler where the working fluid (typically water) is converted to a high-pressure gaseous state (steam) in order to turn a turbine.