How does the AlgaRay work?
Like most great innovations, the AlgaRay robot is surprisingly simple.
Its design and operation is inspired by the Manta Ray which glides through the ocean filtering and consuming the algae it passes through. Similarly, our AlgaRay glides along the surface of the ocean collecting Sargassum seaweed before diving into the deep waters below to release it. An open cavity structure exposes the Sargassum within the AlgaRay to increasing water pressure as it dives. This causes the air sacs that give the Sargassum its buoyancy to compress. Below 135m this air is so compressed that the seaweed is no longer buoyant, the AlgaRay continues on down to 200m depth (just to make sure!) and then releases the seaweed where it sinks under gravity to the seabed. It will return to the surface and repeat the process again, four to six times an hour, throughout the day. The really great thing about this approach is that the system is extremely energy and resource efficient. We only have to move material to the right depth and that’s it, job done. It’s just a simple 200m vertical displacement. There’s no intensive processing required or moving the seaweed out of the water. Crucially the bulk of the AlgaRay isn’t impacted by constant changes of pressure: it’s an open structure, so there’s no need for complicated and expensive pressure resistant submarine-like engineering.
Manta Rays are also famous for having the largest brain to body ratio of all fish. Our AlgaRay is just as smart too: driven by our AlgaOS platform, it will operate autonomously and use Artificial Intelligence and Machine Learning to ensure that collection and deposition is undertaken in the most effective and efficient way possible - always thinking and seeking to maximise its impact. Manta Rays travel alone or in groups of up to 50, which also reflects how our AlgaRays can work. The AlgaRay will deploy swarm robotics for dealing with larger Sargassum mats, or during times when intense removal is required. Crucially, the AlgaRay is being built around a modular cavity design, so its internal collection capacity can be increased easily when required. Offshore, where it can move more slowly (around 3 knots) and remove large volumes steadily throughout the day, it will utilise a system up to 10m wide for carbon removal applications; while nearer to the shore smaller, more dynamic, AlgaRays 3m wide will intercept Sargassum before it reaches the coast for beach defence.
The AlgaRay has an amazing memory too, which is infallible: everything it does is captured on video and recorded with a blockchain. This is vital in order to verify and evidence everything that it does. It’s basically got a built-in digital MRV system, which is really important to give confidence to our customers.
The AlgaRay is on an exciting and rapid development trajectory. The first iteration used a solar driven surface support vessel which provided the power and the mechanical support infrastructure to first drive the collecting cavity along the surface, and then sink it down into the depths of the ocean. A mechanical winch then dragged the scoop back up. It was pretty rudimentary in operation, but it allowed us to test all the principles of collection and sinking. The current AlgaRay is more similar to the Manta Ray that inspired it, and more like the final version we envisioned. It’s not tethered anymore, we have already done anyway with the surface support vehicle. The winch has been replaced with a clever buoyancy system which controls the depth positioning of the AlgaRay simply and effectively. Power for propulsion and sinking/resurfacing activity will come from photovoltaics positioned on the top of the robots which supplies onboard lithium batteries, making the AlgaRay carbon neutral in operation.
Once it becomes autonomous, it will be able to operate irrespective of adverse weather which can be experienced in the area. For now, while we are still developing full capability, the AlgaRay is controlled by an operator on a support vessel. This will transition to a semi-autonomous operation with operators in close proximity on an electric support vessel. We have to be aware that we are not the only operators in the sea, hence the human operator just to keep an eye on things. As the autonomous technology matures, we will upgrade the AlgaRay in line with this, the modular architecture of the system is designed to facilitate and accommodate this development.