Energy and Climate Change CommitteeWritten evidence submitted by Supervawt Ltd (SEV88)

This paper makes it plain that there is a further design for tidal generation in the Severn Estuary beyond Hafren and Evans Engineering proposals. A floating tidal farm that has the least impact on the Severn Estuary, won’t disrupt shipping and leaves fish unharmed.

The current state of the art in technology will be disrupted by Supervawt Ltd’s new design for a fluid turbine. It stands on its head a number of presumptions about lift based vertical axis designs and is not an incremental improvement in design. Testing has already demonstrated that a number of textbook facts for lift based vertical axis designs do not hold true for the supervawt design.

The patent application, which can be made available, makes it clear how the design operates.

As has been mentioned the design produces more power than any existing vertical axis design.

Why is the vertical orientation important? A vertical turbine does not have a tipping point and so is suitable for floating platforms. This is why floating tidal turbines have not been considered before, because the existing tidal turbines are horizontal axis turbines which are not suitable for floating platforms.

The vertical axis design is also advantageous as the central shaft allows the generating equipment to be out of the water which reduces the complexity of the design, construction and maintenance.

The supervawt design has a simple mechanism that allows the orientation of the turbine to match flow direction and speed.

It takes a visionary to see that whilst a barrage must be arranged in a linear development, a tidal farm can be arranged over a larger area with a consequent increase in power generation.

There would be no need to construct a barrage and so no need for a tidal lock and the consequent disruption to shipping. Fish are unlikely to be affected by the turbines.

January 2013