to the diverging section 68 and extending outside the duct 62 to such seawater the converter 61 is placed in the draft tube 67 a classical way to increase the water velocity is to block a tidal current and release it through a small area in which according the invention the converters may be placed see fig1 an mhd converter 61 is placed in a discharge tube 71 which is part of the barrier 72 in this discharge tube section the water velocity is high due to the hydraulic head created by the barrier a hydraulic ram type of kinetic energy densifyer is shown in fig1 it consists of one or more main tubes 81 in which the tidal current 66 induces a flow of water when a critical water velocity is reached valves 82 suddenly close the impulse of the water columns in the tubes now is released at high speed through a relatively small cross sectional area tube 83 enclosing the mhd converter 61 when the velocity in the main tubes 81 gets lower than a threshold value the valves 82 re open again and the process repeats to flatten the pulse wise discharge flow of a single ram tube two or more tubes can be placed parallel hydraulically separated by one way valves 84 in practice the structure could have a 3d appearance as shown in fig1 an mhd converter may replace the air turbine in an andreau enfield.