The Ebb and Flow Of Tidal Power In The UK  

The WSJ has a look at tidal power news in the UK - Tidal-Power Project Ebbs in U.K..

Tidal power has been hailed by some as the wave of the future. But in the United Kingdom, the shifting tides of public policy threaten to leave it high and dry.

Puns aside, last month, the U.K. government withdrew its support for one of the world's most ambitious renewable-energy projects—a $24 billion tidal barrage across the Severn Estuary that potentially could have generated as much as 5% of the U.K.'s electricity. The British government said a two-year feasibility study determined that the project would actually cost about $54 billion, and it couldn't justify public funding of such a high-cost, high-risk project.

But there was another factor weighing against the project: its environmental impact. Though the barrage—which would stretch across the estuary and function a bit like a hydroelectric dam—was pitched as a clean technology, green groups argued it would destroy marsh and mud flats used by thousands of birds, and block the migration routes of fish. The government agreed.

"Harnessing the huge tidal power of the Severn has to be right, but it cannot be right to trash the natural environment in the process," says Martin Harper of the Royal Society for the Protection of Birds, a U.K. charity.

While many people believe the government's decision is a death blow to the project, the private consortium behind the barrage, Corlan Hafren Ltd., has vowed to proceed without government support.

The barrage isn't the first renewable-energy project to run afoul of environmentalists. That may be why interest is growing in the U.K. in another type of marine power that draws fewer objections from green groups: tidal-stream energy. Experts have said 15% to 20% of current U.K. electricity demand could ultimately be met by wave and tidal-stream energy, where turbines are placed in fast-flowing currents or tidal steams and powered by the moving water in much the same way moving air powers windmills.

SeaGen, the world's first commercial tidal-stream generator, operates in Strangford Lough, Northern Ireland, an inlet chosen for its extremely fast tidal current. Marine Current Turbines Ltd., the company behind SeaGen, also is working with a unit of the German utility RWE AG on a tidal-energy farm in North Wales. By the end of the decade, they plan to have major tidal farms off Scotland's Pentland Firth—an area often described as the Saudi Arabia of marine energy—and off the northern Irish coast.