Marine Current Turbines design
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A 300 kW prototype is currently being tested off Lynmouth in Devon.
Expansion of this testing to a 2 x 500kW test-model is planned, with a target of
commercial installations by 2006. This is the most common turbine concept,
where axial flow rotors are used to drive a generator via a gearbox similar
to a hydro-electric or wind turbine. The power units of each system are mounted on
wing-like extensions either side of the tubular steel monopile, and in this design
the rotor can be raised to the surface for maintenance purposes. A similar design
by Seapower Scotland and Delta Marine is planned for implementation in the near future
to supply power to the Shetland grid. back to top
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Stingray by Engineering Business
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A 150kW demonstration model has been installed in the Shetlands.
The next stage is design, build and operation of a 5MW pre-commercial model after 2004.
In this design, a stack of hydroplanes have their angle relative to the water stream altered.
Lift and drag forces cause the arm to oscillate, and a hydraulic cylinder attached to the
main arm subsequently extends and retracts pumping high pressure oil to a motor /generator.
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AWCG by Engineering Business
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A scale model of this concept was built and tested in dry docks in 1999, but little research
has been carried out into the concept since. The Active Water Column Generator features
hydroplanes acted upon by moving water to move a part-sealed collector up and down.
As it moves, air is drawn in and expelled from top of chamber powering an air-based turbine.
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Seasnail by Robert Gordon University and AREG
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This research project is based more around the novel design of the turbine support frame
rather than the operation of the turbine itself. Testing of a half-size frame prototype
has taken place off Orkney, with a full size prototype, capable of generating 750 kW of
electricity planned. The 30-tonne prototype can be taken down to any depth on the sea floor
and back on command. It is expected to be useful for smaller sites and enable planning of
future developments by ease of recording site data. back to top
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Tidal Fence by Blue Energy |
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A 100kW prototype was tested in 80s, and a 500kW pre-commercial unit near British Columbia
is currently in progress. There are plans for a full scale 50MW fence in Phillipines followed
by 2.2GW array. The basic design involves multiple 25kW vertical axis Davis Hydro turbines
installed as a tidal fence array. The Davis Hydro turbine has four fixed hydrofoil blades
connected to a rotor to drive a generator. Via hydrodynamic lift on the blades, the turbine
moves proportionately faster than speed of water. back to top
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Polo by Edinburgh University |
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A working prototype is expected at some point in 2004. The design consists of a vertical-axis
rotor, with the generation plant at the surface in a sealed compartment at atmospheric pressure.
The rotor uses variable-pitch blades where pitch is set by control of the moment about the pitch
axis. back to top
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Rochester / Gentec Venturi by Rvco Ltd |
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A working model (0.6m aperture system) has been tested successfully in Grimsby, and a larger
scale demonstration is expected soon, with a commercial power station to be built in Iceland
this year. The innovative concept involves a wing / funnel which is placed underwater to channel
tidal flows. As the water passes through the choke it decreases in pressure and accelerates,
sucking more water into pipes and driving an on-shore turbine to generate electricity. The
advantage of this design is that it has no moving parts under water and can generate constant power.
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Underwater kite – Abacus Controls |
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A 40-foot wide twin-turbine is intended for deployment in the Gulf Stream off Florida. The 120kW
system also works in tidal basins and rivers. The design features a self-contained moderately buoyant
turbine-generator suspended like a kite within the tidal stream. back to top
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Exim by Seapower, Delta, and Stromturbiner |
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A prototype turbine has been used in tests to find best site for a tidal generator to supply the
Shetland grid. Currently a final evaluation of locations with good streams is being implemented,
with the first production unit expected this year. The design features a Savonius turbine mounted
under a buoy which is anchored so that it cannot rotate with the stream. back to top
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Gorlov Turbine by GCK Technology |
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A permanent turbine array is being installed off South Korea intended to generate 100MW. The plan
is to install 6 twin-turbines in a vertical, side-by-side arrangement. The turbine design itself
is an improvement of the Darrieus design. The blades are similar in appearance to an aeroplane
wing twisted into a helix. Water flowing into the blade causes a thrust force, and blade's
wing-shape generates lift and drag. These forces combine to rotate the turbine faster than the
water speed. back to top
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