Ocean currents caused by tidal movement contain a rather large amount of energy. Mostly the concentration however is rather small. But at certain places the energy concentration, which means the occurring velocity, is high enough for being exploited economically. In order to allow a competitive electricity generation compared to other sources a rather safe, robust and cheap technology has to be applied.
In this paper the development of a tidal current turbine (TCT) is shown. For a robust design a turbine with fixed blades (no mechanical pitch assignment) has been chosen. To account for the changing current velocity the turbine runs at variable speed. For the drive train of the turbine unit mostly standard components (gear box, generator etc.) are used in order to reduced the price and the risk of failure. Figure 1 shows the turbine unit. The turbine has two fixed blades, which are rather large in order to be insensitive to dirt (muscles, sea weed etc.) and to produce a rather large torque at zero speed.
In the presentation the design aspects are discussed in detail.