A rival Severn Estuary barrage scheme is determined to make waves, with claims its design would be less environmentally intrusive than the latest proposal and cheaper.

The revived REEF project would be even longer than the Great Western Power Barrage but is based on a floating structure rather than a concrete embankment.

It would stretch across the Bristol Channel from Aberthaw, west of Barry and Cardiff airport, to Minehead in north Somerset.

The £30 billion-pound Great Western Power barrage  would cover a shorter stretch from Lavernock Point, just south of Cardiff, to near Hinkley Point in Somerset.

The GWP project was discussed at the recent Green Growth Western Gateway conference run by the Western Gateway Partnership.

But Rupert Armstrong Evans, of Evans Engineering, based in Cornwall, said: "Our project is even larger than the Cardiff to Weston barrage but less environmentally damaging and would provide vast energy storage and some flood protection as well. Only the Chinese are actively researching my system, so why is it so difficult to get ideas accepted here in the UK?"

Evans Engineering estimates that the cost of its scheme would be in the region of £20 billion.

Rupert Armstrong Evas said his firm built the world's first 'Tidal dream Turbine' in Cornwall as long ago as 1990 with no Government support and were the first 'renewable energy business' in the UK. He blamed government bureaucracy for lack of progress on his Severn Estuary scheme.

He explained: "The REEF is a system of very large turbines built into floatable concrete caissons, similar in size and structure to those used in the D-Day Mulberry harbours and stretching from Minehead to Aberthaw, a route that unlike Cardiff to Weston has no sandbanks or mud and would generate 50% more energy."

It's claimed the scheme would generate 30.4TW(hrs) per year, or about 12% of all the energy currently generated in the UK each year, and slightly more than the energy expected to be generated by Hinkley Point C when it is completed, at 30.2TWHrs/annum.

The firm claim an added benefit of the REEF Scheme is its ability to 'hold back the tide' and so to a limited extent store energy for when it is most needed by the grid, helping to reduce the need for gas fired generators to be switched on when sudden demand occurs.

Conventional tidal range barrages can have a number of unacceptable environmental impacts.

Because of the low speed and low hydraulic head of this particular scheme, fish would be able to swim without danger through the openings. The tides themselves would still flow in and out of the estuary and so a substantial part of the habitat for bird life would be retained.

Ships would be able to cross the barrier through very large locks (1km long) for much of the time without interruption or the need to close the gates. The gates themselves would operate in much the same way as flood protection works in Venice, which would float to close and sink to open, like a submarine.