In a world concerned about the consequences of climate change, the utilisation of wave energy appears to be a promising alternative to coal or nuclear power. Nevertheless, progress in this sector has so far been rather slow.
The idea started over 30 years ago.
- Copyright AW Systems
The idea for the Waveroller was born back in 1993 when a diver, inspired by the movement of a shipwreck hatch, recognised the possibility of using the power of the waves to generate electricity. Since then, the company has worked intensively on the development of this pioneering technology.
In 2019, the first commercial waveroller was successfully connected to the power grid off the Portuguese coast. Despite the challenges posed by the harsh marine environment, the company proudly emphasised the longevity and quality of the system.
Since 2020, the company has been working with the support of the EU to adapt the technology for series production and use in arrays called WaveFarms. These WaveFarms will sit on the seabed and be between 8 and 12 metres deep, no more than 2 km from the coast.
What exactly is a waveroller and how is the electricity generated?
The waveroller is a device that converts the energy of ocean waves into electricity. The machine operates close to shore (approximately 0.3-2 km from the coast) at depths between 8 and 20 metres. Depending on the tidal conditions, it is partially or fully submerged and anchored to the seabed. A single unit (a combination of a panel and a PTO) has an output of between 350 kW and 1000 kW, with an efficiency of 25-50% depending on wave conditions at the project site. The technology can be used as a single unit or in integrated systems.
The back and forth movement of the water, driven by the wave motion, sets the waveroller panel in motion. To maximise the energy that the panel can absorb from the waves, the device is installed at depths of around 8 to 20 metres under water, where the wave motion is strongest. A single panel absorbs 1.5-2 MW of power from the wave motion. The panel covers virtually the entire depth of the water column from the seabed to the surface.
As the waveroller panel moves and absorbs the energy from the ocean waves, hydraulic piston pumps attached to the panel pump hydraulic fluids into a closed hydraulic circuit. All elements of the hydraulic circuit are enclosed in a hermetic structure within the device and are not exposed to the marine environment. Therefore, there is no risk of leakage into the sea. The high pressure fluids are channelled into a power storage and smoothing system which is connected to a hydraulic motor that drives a power generator. The electrical output of this renewable wave energy power plant is then connected to the power grid via an underwater cable.
The advantages of the Waveroller
- Copyright AW Energy
Waveroller technology offers three unique empirically validated advantages:
Installation: it is installed and operated close to shore – easy site access, protected from extreme conditions and minimised plant infrastructure costs.
Efficiency: It captures energy with a bottom-mounted panel (oscillating wave motion transducer) – highly efficient energy capture, can operate in low, medium and high sea states without shutdown and with only one moving part.
Innovation: It converts motion into electricity and utilises an integrated power storage and hydraulic system – continuous and grid-compatible power output, ability to set up and support the grid, and a low-maintenance design with onshore inverters.
The generator is well positioned to replace environmentally unfriendly energy sources with clean and renewable energy from ocean waves. Utilised by Waveroller, this blue energy source is not only more environmentally friendly than fossil fuel technologies, but also poses fewer risks than nuclear energy and is on par with or even superior to other renewable energy sources.
It does not destroy nature and takes up little space compared to the output.
The technology utilises waves that carry far more energy than wind in an area of comparable size. A waveroller device provides about seven times more nominal power capacity than a wind turbine in a similar sized area.
Apart from its small footprint, a waveroller device operates underwater and has little visual impact. The height of the panel is designed to minimise or completely eliminate its overwater projection to preserve the natural beauty of the sea and coastline.
The device follows the movement of the water, making it very friendly to the surrounding marine life. The hydraulic, mechanical and electrical systems are also completely sealed in the waveroller hull, which protects marine life from noise and other possible pollutants.
AW-Energy operates a globally unique test facility for the waveroller technology in Finland. The test facility enables AW-Energy to achieve significant cost and time savings by testing and optimising PTO units under factory conditions instead of having to conduct expensive and time-consuming sea trials for each individual unit.
What does the future hold for the AW Energy?
The technology has the potential to put Europe at the forefront of innovative renewable technologies and contribute significantly to the European economy, with a projected addition of €275 million and the creation of 500 jobs over the next ten years.
Despite its promising potential, AW Energy global project pipeline is currently rather modest. The company has signed a letter of intent with a clean energy company to build a WaveFarm on the Swakopmund coast.
Waveroller technology could play a crucial role in integrating wave energy into the global renewable energy mix. Its environmentally friendly characteristics and the ability to utilise the energy of ocean waves efficiently make it a promising alternative in the world of renewable energy.
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Sources and further links:
European Commission. (n.d.) Waveroller: Turning Waves into Electricity. Available at: https://projects.research-and-innovation.ec.europa.eu/en/projects/success-stories/all/waveroller-turning-waves-electricity (accessed 04 February 2024).
Interesting engineering. (n.d.) Waveroller: Sea Floor Generator Tech. Available at: https://interestingengineering.com/energy/waveroller-sea-floor-generator-tech (accessed 04 February 2024).
New Atlas. (n.d.) Waveroller: Wave Energy. Available at: https://newatlas.com/energy/waveroller-wave-energy/ (accessed 04 February 2024).
European Commission. (2024) WaveFarm unleashes wave energy for a sustainable future. Available at: https://oceans-and-fisheries.ec.europa.eu/news/wavefarm-unleashes-wave-energy-sustainable-future-2024-01-31_en (Accessed: 04 February 2024).
AW-Energy. (n.d.) Home page. Available at: https://aw-energy.com/ (accessed 04 February 2024).