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Tidal stream turbine

Our turbine design offers the following advantages:

Capital Cost

As our turbine spins much faster than competing devices we do not require a complex multistage gearbox. Also, as our device captures energy from an area greater than the projected area of the device it is more efficient, therefore, for a similar power output to our competitors, our device will be smaller. In the Marine sector, costs quadruple with the doubling of size, therefore our device is likely to be significantly cheaper.

O&M Cost

In the Wind Turbine Industry gearbox and turbine blade are the main causes of failure and represent the majority of Operational and Maintenance costs. This is likely to be an even greater issue for Tidal Stream devices as the forces are greater and the installation sites less accessible. Our device will have a greatly simplified gearbox, (potentially no gearbox at all), significantly reducing servicing costs. Also, as our device creates a vortex before reaching the rotor, the turbulence, which leads to the fatigue and subsequent failure of turbine blades in our competitor’s devices, is eliminated creating a stable force profile at the rotor greatly reducing fatique stresses and therefore rotor failure.

Sea Life Survivablity

All our competitors rely on blades cutting across the water current flow, as a result, sea creatures travelling with the flowing current of water are likely to be killed or injured by the blades. In our device any trapped sealife will pass unharmed through our turbine, (possibly a bit dizzy). This advantage is of particular importance in run-of-river installations.

Siting Options

The cut-in speed of a regular bladed turbine is around 2 meters per second, this restricts the number of sites available to install tidal farms economically to areas of high tidal flows. Our turbine cut in speed is 1 meter per second allowing our turbines to be installed economically in a greater number of sites and are therefore more likely to be nearer to grid connection points on the mainland further reducing costs.

As with wind farms, tidal stream turbines will need to be spaced at least 3 turbine diameters apart to prevent interference from one turbine to the next increasing failure rates due to turbulence induced failures of blades and drive-train and reduced efficiency due to shadowing effects. As our device conditions the flow before reaching the rotor, turbulence is ironed out allowing our turbines to be nested closer together. This increases the amount of extractable energy per square km of seabed and also reduces the length of the cables connecting them, a major contributor to installation costs.

Run-of-river turbine

In the UK alone there are records of there being 5,000 watermills over the centuries and we would expect many of those sites to be suitable for our technology. The UK’s Environment Agency has issued a recent report estimating there are about 4,000 ‘barriers’ (usually weirs) in the UK that are “win – win” schemes capable of generating about 1,800 GWhrs per year.

Also the UN has identified a need for renewable electricity in remote communities in the Developing World, much of which could be supplied by in-river generation. We have had a lot of interest in our technology from Brazil and, with the right partners, expect to capture a significant proportion of the South American run-of-river market. Once this has proven successful we intend to role out a similar technology transfer strategy in Asia and China.

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