Swedish company CorPower Ocean has successfully verified the survival mode of its C4 wave energy device, weathering through two major storms along the Portuguese coast which unleashed waves of up to 13 meters.
The storms marked the most energetic period at the Aguçadoura site in northern Portugal since CorPower Ocean deployed its first commercial-scale device in August .
With major depressions building up over the Atlantic, Storm Babet and Aline unleashed waves up to 13 meters, providing an ideal opportunity to test the C4’s design principle for robust operation in extreme weather .
The storms were widely reported, leaving a trail of destruction across Portugal resulting in strong winds, torrential rain, flooding and building collapses.
Patrik Möller , CorPower Ocean’s CEO, said: “This was our most robust test so far in terms of storm survivability. We are happy to report that the device operated as intended with minimum motion and loads, despite being battered by waves up to 13 meters. The C4 was fully submersed under wave peaks on a regular basis. Last week’s operation has provided solid verification of the C4’s ability to endure extreme ocean conditions.”
The C4’s unique survival mode feature is enabled by a frequency detuning principle. In big storm waves, the C4 exhibits almost no response to the incoming wave power. This limits the loading on the structure to a similar level to regular operation in moderate ocean conditions. The survival mode is the natural state of the machine, making it a passive fault tolerant protection feature.
With the wave energy device operating as intended in survival mode, the loads recorded were slightly lower than predicted by advanced simulation models.
The models have been calibrated in several steps since 2012, by prototype testing in wave tanks and by the previous CorPower C3 scale 1:2 device that was operated at the European Marine Energy Centre (EMEC) in the Orkney islands in 2018.