How much electricity can one marine turbine produce?
The amount of power each turbine will produce depends on the speed of the tidal flow, the size of the turbine rotor, the tidal cycle and the efficiency of the design. There are nearly two high tides and two low tides each 24 hours in the Kaipara. Each turbine will be in action for about 15 hours each day. Spring tides generate more flow than neap tides, and the outgoing or ebb tide is more powerful than the incoming or flood tide. Wind, air pressure and rainfall in the catchment area also play a role in determining the speed of the tidal current. On average each turbine is expected to generate 0.75 MW. The formula is : P = dAV3Cp d = density of seawater (1.025 kg/m3) A = swept area of the blades (m2) V = velocity of the currents Cp = power coefficient Thus the current speed and blade radius are the major factors determining power output. Water is non-compressible and 830 times denser than air which also contributes to the high power output. Crest also knows that the ebb tide is not exa
