Tidal Power’s Surprising Comeback

Below Sea Level: LaRance’s turbine hall

Can a U.K. firm’s novel plant design defuse environmental concerns?
By Peter Fairley

Fifty years ago this July, Électricité de France began sealing off Normandy’s La Rance estuary from the sea. After three years of work, the world’s first large-scale tidal power plant was born. The station operates still, generating up to 240 megawatts of renewable power as the twice-daily tides force water in and out of the estuary through the hydroturbines seated within its 750-meter-long seawall. But the three years of construction were tideless, which devastated La Rance’s ecosystem, killing off nearly all of its marine flora and fauna; it would take another decade for the estuary to bounce back. Due in part to that ecological hangover, La Rance would remain the only tidal station of its scale for nearly five decades …

Excerpted from the July 2013 edition of Spectrum Magazine. Get the full scoop via Spectrum.

UK Rejects Tidal Barrage, but Smaller Tech May Endure

The UK government has shelved schemes to build a tidal barrage across the Severn estuary, West of London, that could have supplied 5% of the UK’s power needs. What reports are missing is the endurance of more nimble tidal turbines and other marine power devices–distributed energy devices that the UK is helping to nurture.

Barrages are essentially hydro dams that capture each high tide and generate electricity from their outflow.The first large barrage and largest currently operating crosses the estuary of the Rance River on France’s Atlantic coast, generating a peak of 240 megawatts–the scale of a large wind farm. Five competing proposals for a Severn barrage were to generate up to 40 times that much from the region’s 14-meter tides. Continue reading “UK Rejects Tidal Barrage, but Smaller Tech May Endure”