Endless energy - The Renewed case for Tidal in the North Sea

Endless energy - The Renewed case for Tidal in the North Sea

Tidal energy in Europe just got a boost with the go-ahead for a demonstration project off the coast of Scotland’s northern coast. The Pentland firth has some of the fastest tidal currents in the world. If the six vast underwater turbines prove the concept, then more than 50 will be installed on the seabed off Caithness.

Meanwhile in Northern France, Tidalys - a French company backed by a Dutch private equity firm, has already won a national innovation award for its floating turbine. The West Normandy Marine Energy board is confident that by 2020, 4% of European electricity production will come from renewable marine energy.

Eric van den Eijnden, CEO of Dutch Expansion Capital, says all the numbers now favour a renewed look at tidal energy projects in the North Sea off the Dutch coast.


“The Tidalys turbine generates clean energy at half the cost of off shore windmills, without the challenges that they bring of horizon pollution. In addition, initial construction, installation and maintenance costs of this new design of turbines are significantly lower than competing designs. The floating structure is easy to manoeuvre into position and all electrical components remain above the water surface. The design can withstand the fiercest of storms ever recorded. ”
“In short, we can offer a much cleaner solution than conventional land-based power plants. Our designs and technology mean our total generating costs reach price points similar to nuclear energy but with considerably lower investment, environmental impact and much faster payback time”.


Engineers have been looking at ways to tap into this huge natural energy sources for decades. Unlike wind or solar power in this part of Europe, whose strength is often difficult to predict, the advantage of tidal power is simple; the high and low tides are always there and can be predicted very accurately. Ocean tides are the result of the gravitational interaction between the Moon and the Earth's rotation. Which means the power is endless and not subject to any political actions here on earth. No-one can turn the Moon off!

Water is over 700 times the density of air, so that mean a tidal turbine produces much more energy for the same size turbine blades. The process is totally carbon neutral because no carbon dioxide is released into the atmosphere. And the earth is the energy source.

French engineers have had a dream to harness the tides for decades. In fact, a study 60 years ago suggested that a barrier across the river Rance in Normandy could generate power from the tides at its mouth. But it took 20 years before work started on the project on July 26th 1963. With a peak rating of 240 MegaWatts, the 24 turbines are still in operation today.


So, if the tides have so many advantages, what has stopped the industry from scaling up so far? Arnaud Blosseville, CEO of Tidalys explains the reason is simple.
“Costs have held things back. The original construction of the Rance dam took three years to build. The bill in 1966 was the equivalent of €94 million. That would be billions today. It took 20 years for the scheme to pay for itself. And blocking the mouth of the river has ecological impacts as well.”

“We have taken a completely different approach with Tidalys. We’re able to show that we can vastly reduce the costs of reliable tidal power to a point where it becomes the cheapest renewable energy source in the world.
We have taken a very different approach to achieve this. Others have tried to build turbines on the sea floor. But these are extremely difficult and expensive to maintain. Hauling the heavy machinery to the surface requires specialized vessels.”
This is why the Tidalys design involves constructing a floating turbine. That means the turbine propeller can automatically align itself to the direction of the current, making the most efficient use of the natural energy source. We’ve actually adapted knowledge and designs from very different industries: because those who design aircraft propellers and Formula 1 racing cars have always tried to push designs to the limit.

The Basse-Normandie coastline around Cherbourg, known as Raz Blanchard, has ideal natural conditions for tidal energy production. The velocity of the current often exceeds six metres per second, which translates as an energy generating potential up the 6 GigaWatts. And the proximity of the Maine-Cotentin high voltage power lines means that the energy generated can easily and cheaply be pumped into the French national grid.


But Eric van den Eijnden believes that the technology is highly relevant for the slower moving currents in the North Sea.
“This technology has reached its tipping point. New materials and computer modeling have reduced the cost and speed of development. Our goal is high reliability combined with light weight and low maintenance.”

“And we have uncovered a wealth of relevant expertise in the Netherlands. Fokker, has over 100 years of specialist knowledge of aero-dynamics. Airborne Marine are industry leaders in the supply of turbine blades. They have unique knowledge of materials. And Vryhof are the company that off-shore platforms rely on for heavy duty anchoring and mooring. Together with German and French suppliers, we know we have the winning combination to make this a major global business.”

“Tidalys will always team up with local partners so that the construction of the turbine systems generates local jobs. It doesn’t make sense to manufacturer parts in East Asia and then ship them half way around the world. In the end that’s false economy. And think of the carbon footprint. We have already shown that scale models are reliable as well as robust. And this science is already proven. So we’re now ramping up to build a full size prototype very soon.”

“We’re now looking to the Dutch government to give the go-ahead to a similar tidal energy park in the North Sea as we have seen in Scotland, France and Wales.”
“We’re convinced that what we’re building here is going to change the world of renewal energy production. That’s not only good news for the North Sea region. It’s great news for our planet.”