An organic Rankine cycle (ORC), is fundamentally the same as a steam Rankine cycle; however, it uses a lower boiling point organic fluid to better match its operation to lower temperature heat sources. ORC systems can achieve better efficiencies than steam turbines for smaller systems (less than a few MW_e).

Opteon™ MZ working fluid is the best choice for organic Rankine cycle systems.

for a typical ORC installation with an electric output power of 1 kW, used the R245fa as refrigerant obtained a thermal efficiency of the system from 0 to 6% depending on the working conditions [29].

This study considered five different working fluids for ORC, such as R245fa, Benzene, Methanol, Ethanol, and Acetone. The ORC generates additional electricity of 9.91 MW e for R245fa, 14.11 MW e for Benzene, 13.71 MW e for Methanol, 14.04 MW e for Ethanol and 13.97 MW e for Acetone.