Wave energy has never taken off: two plants in Portugal and Scotland are about to change that

While there are renewables such as solar or wind that are accelerating decarbonization, others remain a melon to open. This is the case of wave energy. The potential of waves is enormous, as island countries like Japan and rough coasts like Galicia know well, but half a century later it is still stuck in the experimental phase.

There is some installation, such as the one in Mutriku, but its size and performance are discreet. To take wave power to another level, you need technology reliable enough to create a large plant and someone external to attest to it. There the fence is reduced to two places and one company: Portugal and Scotland, both with the help of the Swedish CorPower Ocean.

CorPower Ocean's C4 power converter measures nine meters in diameter, 18 meters in height and about 100 tons in mass. Since 2023, it has been installed and operational in the testing phase four kilometers off the coast of Aguçadoura, in the north of Portugal, at a depth of 45 meters.

The device has achieved a historic milestone: it has received the first prototype certificate awarded by Det Norske Veritas, the world reference entity in offshore energy. In practical terms, it means that the technology meets the requirements for resistance, reliability and security. In addition to the conceptual development, detailed engineering, structural fatigue analysis, manufacturing, assembly and installation, the most striking thing is that its performance in storms with waves of up to 18.5 meters has been approved.

Wave energy has been the pending issue of renewables for more than half a century, far behind in performance and exploitation compared to wind or solar. That an independent certification body has given the go-ahead means that the technology is ready to make the leap into commercial production in terms of performance and safety.

Here is the crux of the matter: if the technology is reliable, it is easier to convince financial and investment entities that it is worth betting on it.

Since the first prototypes were patented in 1981 by engineers Laithwaite and Salter, other states such as Japan, Spain and Italy have tried it without much success. Among the problems are the unpredictability of the waves—variable in height, pace and direction—and the difficulty of the marine environment for the design and maintenance of the devices.

Certification is not the final stage, but the beginning of commercial implementation: CorPower is already preparing its first two commercial parks, in Portugal and Scotland, with the stated objective of placing wave energy as the third major renewable source next to wind and solar. If everything goes according to plan, they will enter into operation between 2027 and 2029. Their next model, the C5, is already pending certification.

What has been certified is a prototype, not a mass-produced device, which is the next step necessary for large-scale production. And older plants like Mutriku, in operation since 2011, show that this energy produces considerably less electricity than expected compared to wind or solar, with a yield of 11%. It remains to be seen whether these new parks will meet expectations.