THE TURBINE BE LOCATED AT THE SURFACE OR ON THE SEA FLOOR ?
it is possible, it is better to use a floatting current converter, whith a
turbine just below the surface.
surface technology is five times cheaper than underwater technology (development,
construction, repair, maintenance and removal).
turbine will receive numerous operations all along its life: cleaning, small
corrective maintenance, preventive maintenance, repairs, checks, installation
or change of sensors and gauges, improvements, upgrades, refitting, and,
at the end, removal. For subsea current converters set on the seabottom,
these operations can be done only by getting the turbine out of the water
which requires heavy means, hardly available and costly. The cost of repairing
an underwater turbine can possibly exceed its value.
currents are generally stronger near the surface than in the bottom. Look
at the well known ADCP record below showing how the current velocity decreases
looking at this picture, you immediatly know where to settle the current converter
15% current velocity loss results in a 50% power loss.
made for a 2,3 m/s current velocity)
reason is quite simple: in the power formula the current velocity has
a cubic factor:
d Cp S V³