Wave power has been the poor cousin of renewable energy technologies. The ocean is always moving, and we know there’s this vast clean source of power endlessly lapping at our shorelines. Tapping it has so far been quite tricky, but a variety of technologies have been developed and piloted, with a few installed commercially. There are wave capturing steel floats, undersea turbines and buoys, among others.
British company Zyba have a new idea that caught my attention. They are developing a wave power unit that doubles up as a form of coastal protection and grows an artificial reef.
The energy generating unit is called a CCell, and it’s an 8 metre high anchored paddle made from glass fibre composites. Waves hit its flexible curved surface and push it back, and the energy from the motion is captured. The curved shape of the CCells make them very strong for their weight, and they’re resilient to storms and extreme weather. It’s also very simple. The fewer things there are to go wrong, the less maintenance there will be. CCells have just ten parts, and they are designed to last for a decade. Here’s one being tested in a tank:
Where it gets really interesting is on the sea floor though. Zyba plan to anchor the CCells to a wire mesh and then grow a natural concrete on it, creating a breakwater and encouraging coral formation. 90% of the energy generated by the wave power system would be exported to the grid. The remaining ten percent would be directed towards the Biorock process, which is an established method for growing or repairing coral reefs.
Biorock works by running a small electrical current through a steel mesh, extracting calcium carbonate and other minerals from the seawater and building up layers of ‘seacrete’. Two or three centimetres of seacrete form every year, creating a platform for corals to colonise. Coral grows four times faster under these conditions, and since climate change is threatening the complete destruction of the world’s coral, this is a potentially important technique.
There are multiple benefits to this system. Clean energy is generated. A natural concrete breakwater develops, reducing erosion and protecting coastal communities from storm surges. Reefs are created, which in turn provide a habitat for fish. That makes it a technology that address both climate mitigation and adaptation at the same time, and that enhances the biodiversity around it – a nice example of restorative development.
- Feature image by Johnny Chen