Ex-minister pressing for barrage

“There are just a few major concerns that stop us extracting energy from the seven. They are mostly environmental and revolve around it being a barrier. You let the tide in , block it off and then use effectively hydro power to extract the energy.
Other concerns are about how wildlife passes through the barrier because most schemes talk about horizontal or vertical type blades that have a chopping action in the water.
The obvious answer is to mearly extract the energy out of the tide flowing past. Using non chopping type actions. There are really only two types of technology I know off
1) Oscillating devices (like pulsetidal's device)
2) Watermill type devices (like Hales Turbines device)
Both do not have chopping actions, but the hales turbine is far easier to stack vertically so that as the tide rises the complete cross section of the tides energy can be extracted
There are some other advantages as well relating to simple design, no wake effect on exit.
What's the problem you ask? – People get married to an idea and it's tough to think outside the box”

“There are just a few major concerns that stop us extracting energy from the seven. They are mostly environmental and revolve around it being a barrier. You let the tide in , block it off and then use effectively hydro power to extract the energy.
Other concerns are about how wildlife passes through the barrier because most schemes talk about horizontal or vertical type blades that have a chopping action in the water.
The obvious answer is to mearly extract the energy out of the tide flowing past. Using non chopping type actions. There are really only two types of technology I know off
1) Oscillating devices (like pulsetidal's device)
2) Watermill type devices (like Hales Turbines device)
Both do not have chopping actions, but the hales turbine is far easier to stack vertically so that as the tide rises the complete cross section of the tides energy can be extracted
There are some other advantages as well relating to simple design, no wake effect on exit.
What's the problem you ask? – People get married to an idea and it's tough to think outside the box”

“I'm strongly in favour of making the best use of the renewable energy available due to the very large rise and fall of the tide in the Severn Estuary, just not by building a huge barrage across the whole estuary. A barrage is not remotely a win-win.

The barrage would be a vast civil engineering project, consuming vast resources. The financial costs alone would be enormous - more than £30 billion. A huge project means huge impacts, particularly environmental ones (the estuary is very rich in bird life and ecolgically speaking is very productive). There could also be huge economic and social costs because such projects are often plagued by huge cost rises due to delays and unforseen problems. Even if there were no delays it would take a long time to build it - but we need to become more efficient and renewable now!

The idea of building tidal lagoons in the estuary to extract tidal energy is a much better one. Tidal lagoons would not cut across the whole of the area. They may well have a postive impact on biodiversity and would not destroy bird habitats. Lagoons could be built a few at a time, each one having a much shorter construction time than a huge barrage. More lagoons could be added, over time, spreading the financial costs and risks.

We need a proper energy strategy that puts the highest emphasis on energy saving and efficiency and then clean, green energy generation. Being in favour of renewable energy in general terms does not mean being in favour of every single proposal. Its very important to back the project that has the best combination of social, economic and environmental benefits. In the case of tidal energy from the Severn I believe 'smaller is more beautiful'.”