The Tide Is Turning, Part 2  

The Glasgow Herald reports on a new tidal energy era for Dounreay.

Tidal energy production could replace nuclear research to support the economy in a remote part of the Highlands, the Scottish Government said yesterday. Environment secretary Richard Lochhead visited Dounreay - Scotland's biggest nuclear site - where a massive clean-up operation is expected to last until 2025.

Decommissioning will lead to radioactive waste being stored in the area and the buildings will be flattened. Union leaders have said more must be done to find alternative jobs to keep some of the 2000 employees in Caithness.

Mr Lochhead met community representatives at Thurso where he was briefed on progress to regenerate the economy - including the development of a new tidal power station in the Pentland Firth.

Further south, the BBC reports on the haggling over what sort of tidal power facility to build in the Severn estuary - Severn tidal 'fence' idea floated.

Plans for an alternative tidal energy project to a £15bn Severn barrage have been put forward by opponents. Those behind the idea say it will allow shipping to move freely and keep ports at Cardiff and Bristol open and provide a balance with wildlife concerns. ...

Backers of the barrage - which is facing a government feasibility study - say it will provide a huge amount of renewable energy at a stroke, providing 5% of the UK's needs. A feasibility study on behalf of the Welsh Assembly Government and UK Government was announced in January.

But conservation groups claim the £15bn dam, spanning the Severn estuary from Lavernock Point near Cardiff, to Brean Down, near Weston-super-Mare, would affect wildlife.

Now STF Group has been formed and will lobby Parsons Brinkerhoff, the company behind the feasibility study into tidal power. Key to its strategy is that a tidal "fence" would leave open major ports which it claims might otherwise be forced to close if a barrage is built across the Severn.

The fence, which it is estimated would cost around £3.5bn, is a continuous line of underwater tidal current turbines, which would force water flow through them. It would be around 9km long, in three 3km sections, passing near to the Bristol channel's two islands.

Although the fence would produce less energy, STF Group claims this approach would be a compromise between conservation, commercial interests and renewable targets.

Marc Paish from the STF Group said the fence would have a capacity of 1.3GW - slightly more than Sizewell B nuclear power station - and provide around 1% of the country's electricity supply. "Importantly, the fence would allow shipping to pass through and so keep the ports of Cardiff and Bristol open, whereas the barrage risks their closure," he said.

In addition to the tidal fence, the group is suggesting a small barrage or tidal lagoons to ensure continuous output - and which could bring the total capacity to 2% of UK supply. The fence would produce most power at the middle of the tidal cycle, whereas the barrage or lagoon would produce most power at high and low tide.

David Ehrlich at Cleantech.com has an article on a new (albeit small) tidal power development in Brittany - Tidal power gets modern in France.

The country that built the first tidal plant in the 60s is getting a pilot project from EDF, which plans to put turbines off the coast of Brittany. State-owned Electricite de France is bringing tidal power up to date in the country, announcing plans to put three to six turbines off the northern coast of Brittany.

EDF operates the world's first tidal power plant, the La Rance tidal power station, which was inaugurated in November 1966. It's one of only three barrage plants in the world, and it's the largest, producing 240 megawatts of electricity on the Rance River.

But the La Rance barrage, also sited in the Brittany region, has since fallen out of favor for being too damaging to the environment. Today's systems usually involve individual, sometimes free-floating, turbines, as opposed to the barrage system, which is similar to a dam.

"We are going choose a technology, and pass the contract to some constructors and they will build the turbine, and we will finance them and use them," Caroline Muller, spokeswoman for EDF, told the Cleantech Group.

Muller would not say which companies EDF is talking to, but the energy operator plans to go with firms that have proven systems. "We have tendered towards constructors that have already tested their prototypes in real conditions," she said.

The grid-connected project is expected to cost between €23 million to €27 million, or $36.4 million to $42.8 million, with a total capacity of between 4 MW and 6 MW. The turbines are expected to go in the water by 2011 off the coast of the city of Paimpol, where EDF said the currents are among the strongest in Europe.

The company said tidal power could make a significant contribution to the production of electricity from renewable sources in the region, with France having the potential to generate 10 million MW hours per year from the tides.