The efficiency of power plants with supercritical steam generators is higher than that of subcritical steam, since, at supercritical pressure, the steam at higher temperature is more efficiently converted into mechanical energy in the turbine.
It is generally considered that: the efficiency of the supercritical generator is higher because to generate the same thermal energy, less fuel is needed; Exhaust emissions, especially carbon dioxide, are relatively lower due to lower fuel consumption for the same generation, and the size of the boiler is relatively smaller with the same installed capacity.
When talking about supercritical conditions, currently, several conditions can be distinguished:
Supercritical.
Ultra-supercritical.
Advanced ultra-supercritical.
What should be noted is that the design and operation of this type of plants lead to certain specifications and considerations when handling these conditions, from the point of view of mechanical design, feed water and steam treatment, safety, among others.