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How does higher operating temperature affect the efficiency of an MHD power plant?

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magnetohydrodynamic power generator Comparison of the operating principles of (A) a turbogenerator and (B) an MHD generator.

In a magnetohydrodynamic (MHD) power plant, higher operating temperatures significantly increase the potential efficiency of the system.1

According to the Carnot cycle, the maximum theoretical efficiency of a heat engine is determined by the difference between the hot source temperature and the cold sink temperature, divided by the source temperature. Because MHD generators can operate at much higher temperatures than conventional rotating mechanical turbines, they offer the potential for higher ultimate efficiency—typically in the range of 60 to 65 percent, compared to the 35 to 40 percent achieved by modern conventional plants.1

Furthermore, high temperatures are essential for the functional performance of the generator. For an MHD system to operate competitively, the plasma must reach a temperature above approximately 1,800 K to ensure sufficient electrical conductivity. While higher temperatures improve efficiency and performance, they also necessitate the use of specialized materials and seeding additives to maintain the required ionization levels.23