How are tidal turbines tested?
At the early design stage, test tanks, such as those at Plymouth University’s COAST Laboratory and Centrale Nante’s LHEEA Laboratory, are used to prove basic principles of operation and to understand performance characteristics.
It’s very important that tidal components and the complete tidal turbine system are thoroughly tested before going into the water for the first time. In the UK, the Offshore Renewable Energy Catapult manages a range of specialist test equipment at its test centre in Blyth to test turbine components and complete turbines. At Blyth turbines can be run for the equivalent of many years, this is called accelerated life testing, and helps to uncover weaknesses and highlight potential system failures.
In France, facilities such as the French Institute for Marine Research IFREMER test laboratory in Boulogne-sur-Mer make it possible to carry out tests on a reduced scale.
Once the turbine has been tested on land it can be tested in at-sea test facilities, such as the European Marine Energy Centre (EMEC) in Orkney, or the Paimpol-Bréhat tidal turbine test site in Brittany. These two open-air test laboratories provide developers of tidal turbine technologies with purpose-built, accredited open-sea testing facilities, making it possible for independent organisations to certify the tests.
EMEC operates two separate tidal test sites in the waters around Orkney. At the full scale test site at Fall of Warness, subsea cables run from each test berth at sea to a substation onshore where electricity generated at the site can then be fed into the UK national grid.
Paimpol-Bréhat has only one berth connected to the national grid, located 15km from the coast and at a depth of 35m, in a demanding environment (strong currents, exposure to the swell, distance from the coast).