The fuel cell produces a power output of 1198 W at a current of 24A. It has 50% efficiency and hence produces an equal amount of waste heat. That waste heat is used to drive an organic Rankine cycle (ORC), which in turn produces an additional 428 W of power at 35% efficiency.

Additionally, ORCs eliminate the need for full-time plant operators because they operate at lower pressures and do not need water chemistry maintenance. However, working fluid cost, decomposition, temperature limits are an organic Rankine cycle's primary disadvantages.

Answer: (η_T)_Rankine = 30.4% (there is no change in (η_T)_Rankine to three significant figures). Note that the interstage reheating used in Example 13.7 increases the Rankine cycle thermal efficiency by only 0.8%. However, it has the much more important effect of reducing the moisture content at the turbine exit.

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).