IIRC, a cascade of turbines, going from high-temperature water steam to basically room-temperature ammonia, can reach a total efficiency exceeding 50%.
Of course, ammonia is chemically active, and water at 700K is also chemically active, so the turbines, as usual, require special metallurgy and regular maintenance.
Of course, ammonia is chemically active, and water at 700K is also chemically active, so the turbines, as usual, require special metallurgy and regular maintenance.