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Harnessing the Dance between the Moon and the Planet

Anja Kueppers, Swansea Bay, WalesApril 22, 2015

Swansea Bay in southern Wales could soon host the world's first energy-generating tidal lagoons. The British government says it may support the project, which combines technology with a local appreciation of the tides.

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Geplantes Wasserkraftwerk Tidal Lagoon in Swansea Bay, Großbritannien
Image: TLP

"We're a tidal nation," says Mark Shorrock, CEO of Tidal Lagoon Power.

He's the man with a somewhat low-tech, but very green vision. "It's free. It's ours. It's the dance between the moon and the planet. Why wouldn't you want to harness that?"

Shorrock has worked hard to persuade the UK government that tidal lagoon technology, coded by Mother Nature, is an excellent low carbon energy option.

"We reckon 20 percent of UK energy should come from tidal," says Shorrock, who sees up to 13 more tidal lagoons in the offing.

Geplantes Wasserkraftwerk Tidal Lagoon in Swansea Bay
The project harmonizes with the understanding of Swansea locals of the tidesImage: DW/A. Küppers

First of its kind

The British Government knows it needs to put more renewable energy projects on the fast track if it's to reach its 2020 carbon reduction goals. And, last month, when Britain's Chancellor of the Exchequer announced the much-hyped budget update, he confirmed that negotiations on the billion-euro tidal lagoon plan had moved into a more advanced stage.

The initial site in Swansea Bay is meant to serve as a prototype to show that high tide locations can be cost-effectively used to harvest energy.

If successful, the world's first man-made energy-generating lagoon could power more than 155,000 homes thanks largely to the coastline topography - and the topography just off the coastline - which makes Swansea Bay's tidal range much larger than most other places in the world.

Ton Fijen, Tidal Lagoon's technical director, unabashedly acknowledges that the plan for Swansea Bay, including the creation of a 9.5-km wall to hold back and guide massive amounts of water through energy-producing turbines, relies on technology that goes back centuries, even a millennium.

Ancient tidal mills, designed to take advantage of tidal power, still dot the British seaside and riversides. Only a few, most now serving as museum pieces, are in working order, but they illustrate what once was - and what could be again.

"We're using existing technology in an innovative way", says Jane Davidson, a former lawmaker in the Welsh Parliament who's now teaching at the University of Wales Trinity Saint David, an institution that will benefit from the proposed tidal lagoon. She says there's been a lot of talk of harnessing tides across the centuries.

Tidal Lagoon Power plans to dredge part of Swansea Bay, then lay down a long, looping breakwater with a modern sluice gate, maneuvered for maximum efficiency by its own computer applications.

Geplantes Wasserkraftwerk Tidal Lagoon in Swansea Bay, Großbritannien
Water rushes in, water rushes out - the Swansea project looks to harness the energy of the surroundingsImage: TLP

Big bathtubs

A step up from the tidal mills of the 11th century, water will roar through as many as 16 huge turbines as the tide comes in, and then again hours later as the tide goes out. It's this rushing water that will create energy to power TVs, refrigerators, lights and industry in Swansea. And it's the turbine technology - another bit of clever tech from the past - that could push the UK and other high tide zones around the world into the future.

The six miles of breakwater that create the lagoon - a "big bathtub" as Tidal Lagoon Power's Shorrock calls it - will be topped by a bike and walking path, a visitor and educational center, art installations, aqua farming locations and boating, all making the idea more palatable to locals.

Some, like Swansea resident Chris Pallatt, seem happy to embrace the low carbon experiment.

"I know it's expensive, but what are the alternatives? I'd rather that than a nuclear power station."

But the sheer scale cost of the project, requiring decades to payback, are a concern to others. "I think it's an awful lot of money," says Pat Clement, also from Swansea, "and it's not going to get the return that's expected."

Mark Shorrock , TLP
Mark Shorrock is credited with envisioning the idea of the tidal lagoonsImage: TLP

Old merges with new

Regardless of the skepticism in a part of the world where coal was king only a few decades ago, there's now a buzz of expectation regarding the tidal lagoon proposal, says Ian Isaac. He's a former coal miner who's active in promoting the project as part of a revitalization of Swansea's once hardworking harbor. Isaac says that although the clean technology is based on low-tech advances, it will "last for 100 years, and has the potential to be rolled out nationally."

That kind of argument is music to Mark Shorrock's ears.

"If we can prove the first one, a lot of countries can dust off some very decent engineering drawings from the last century", says the CEO of Tidal Lagoon Power.

Shorrock sees dozens of possible locations around the world, including the Bay of Fundy in Canada, coastal India, and the inlets not far from northwest France's Mont St. Michel, as potential candidates to embrace this modern version of very old-school technology.