Vertical Axis Water Turbine
The energy extraction from a vertical axis water turbine (VAWT) has been simulated. The flow through a channel driven by the tide for example can generate a lot of energy in the form of electricity. On the axis of the turbine (Darrieus Waterturbine) a dynamo can be mounted, and the conversion of mechanical rotation energy into electrical energy can be efficient. In this case three blades were mounted in a test rig, and the measurements of the power of the system were compared with the simulation software.
The initial investment needed for such installations is typically high. To make it worthwhile and obtain a high power yield, a large number of turbines would be required. However, as fish are known to collide with the turbines placed in their stream, the authorities have imposed guidelines that allow no more than 0.1% fish mortality per passageway. The system has been tested, and has been proven to meet these specifications,
FEM simulation of VAWT.
The turbine is designed to be self starting, due to a confidential system to control the blade orientation. The turbine can be used in rivers while fish can still pass the turbine system.