The main aspect of this project is to describe and model the water/steam cycle in super critical pulverised coal fired power plants. Then use that model to investigate the potential of a ultra-super critical pulverised coal fired power plant. The Unit 3 in Nordjyllandsværket is chosen as base for the modeling of a steam/water cycle in super critical power plant because of the high thermal efficiency and it is regarded for many as the state of the art super critical coal fired power plant. A model is developed and it is concluded that the model is fairly accurate, when comparing the solutions from the model with design data from unit 3 in Nordjyllandsværket. The model is also verified by investigating the tendency for the solutions when altering the temperature and pressure inputs. The tendency is as expected. A investigation of the potential of ultra-super critical steam data is performed. The tendency in the solutions is as expected and shows increased thermal efficiency when the temperature and pressure of the steam is increased. By raising the temperature from 580 °C to 760 °C and the pressure out of the high pressure feedwater pump from 33 MPa to 42 MPa, the thermal efficiency improves by about 4%. This improved efficiency is in accordance with resent literature on the subject and supplements further to the verification of the model.