Severn Barrage UK Why no progress?

As you say the Severn Barrage could be a major source of energy for the UK Sadly UK politics - where is the payback before the next election? - and UKresistance to change - yes there will be environmental changes, but the losses are manageable aganist the gains.

However, the option of installing tidal turbines, as being installed this week by Marine Current Turbines - see marineturbines.com - in Northern Ireland, is a sound one. The largest turbine being currently installed is a paired reversible rotor on a single tower delivering 1,5 Mw at peak tidal flow, and these are installed in farms of several machines using the same grid link.

With a tidal range in the Severn of 12 metres and thus very rapid currents, a good generation potential is possible without disturbing the wildlife or the shipping flow. Tidal power is entirely predictable and thus the energy has higher value than wind produced energy.

Clearly a dammed barrage would give more energy, but the cost and time scale gains of separate tidal turbines are clear.

While the Hudson project is a step in the right direction, I don't think the reversible pitch turbine was available in the design phase of the project. There is currently a tidal hydro project in the Bay of Fundy (and area on the east coast of Canada with some of the highest tidal flows in the world). They are currently getting ready to install fixed turbines produced by Cleancurrent. These incorporate the bi-directional blade design that allows them to function with water passing either direction.

You can view it here.

As for the environmentalists, I can only suggest hitting them with a free-fallen (not cut), unadulterated (no chemical or mechanical manipulation that involves anything that isn't biodegradable or found intact in nature) stick.

(My personal preference is a new axe handle, carved as the only product from an entire old growth California Redwood tree, painted in lead based paint and previously used to club baby seals. Nothing like understatement to get your point across.)