‘Tidal energy double of world’s nuclear capacity by 2050’
Electricity made by using the movements of the tides can be double of the world’s nuclear energy by 2050, experts say, as technology in this field is maturing fast. It could provide 10% of all energy needs by then, good for 76 million households, the EU estimates.
In June 2018, at the closing days of the International Conference on Ocean Energy (ICOE) in Cherbourg (France), the world’s first tidal turbine factory was inaugurated nearby in Cherbourg. The Naval Energies’ plant will be able to produce 25 of its 16 metre diameter underwater turbines per year initially, but can expand production capacity in the near future.
Turbines at 30 metre depth
For now the tidal turbines will serve in the Normandie Hydro Project off of Alderney Island in the Alderney Race or ‘Raz Blanchard’, as called by the French. Seven turbines placed at 30 m depth will provide about 14 megawatts.
The Alderney Race is a strait that runs between Alderney and Cap de la Hague, a cape at the northwestern tip of the Cotentin peninsula in Normandy (France). Tidal currents are strong there, up to 12 knots at certain times, providing a never-ending source of energy.
Inexhaustible source of energy
As tides are caused by the gravitational force of the moon and have an effect worldwide, they are an inexhaustible and always available source of ‘blue’ energy, provided you have the technology that can resist the strong forces and the salty environment of the sea.
Two methods have evolved farthest to be commercialized: using the tidal forces or using the force of the waves, swept up by the wind. For tidal energy turbines or underwater rotors are mostly used that can be mounted horizontally or vertically in the tidal stream.
The rotor can also move constantly under an anchored underwater wing, which allows to point always toward the changing currents. Comparable to a wind mill turning always in the wind.
To use wave energy systems are developed like a float moving up and down along a pole, a swinging peddle anchored on the seabed or a water column moving up and down compressing the air in a tube, propelling a turbine at the end, among others.
According to the EU, this ‘blue energy’ is needed in the future. While solar and wind energy increasing with 75% between 2013 and 2016, it still represents only 10% of all energy sources. A major benefit of tidal energy is that it’s always available, something you can’t expect from wind and sun.
400.000 new jobs
Ocean Energy Europe (OEE), the network of blue energy professionals with some 120 European industries, agencies and research institutes, estimates that this emerging industry can create 400.000 new jobs in Europe in regions that saw jobs and income disappear with declining shipping and fishery.
“Biggest challenge now is to push down costs”, says Donagh Cagney from OEE. “Therefore you need subsidies, especially in France and the UK, where the potential for tidal energy is the highest. You need a financial boost to start to follow the path of wind and solar energy where prices are going down and subsidies are no longer needed.”