WaveRoller
WaveRoller is a device that converts ocean wave energy to electricity. The machine operates in near-shore areas (approximately 0.3-2 km from the shore) at depths of between 8 and 20 meters. Depending on tidal conditions it is mostly or fully submerged and anchored to the seabed. A single WaveRoller unit (one panel and PTO combination) is rated at between 350kW and 1000kW, with a capacity factor of 25-50% depending on wave conditions at the project site. The technology can be deployed as single units or in farms.
The back and forth movement of water driven by wave surge puts the WaveRoller panel into motion. To maximize the energy that the WaveRoller panel can absorb from the waves, the device is installed underwater at depths of approximately 8 – 20 meters, where the wave surge is most powerful. A single panel absorbs 1.5-2 MW of power from the wave surge. The panel spans essentially the entire depth of the water column from the seabed up to the water surface level.
As the WaveRoller panel moves and absorbs the energy from ocean waves, hydraulic piston pumps attached to the panel pump hydraulic fluids inside a closed hydraulic circuit. All the elements of the hydraulic circuit are enclosed inside a hermetic structure inside the device and are not exposed to the marine environment. Consequently, there is no risk of leakage into the ocean. The high-pressure fluids are fed into a power storage and smoothing system, which connects to a hydraulic motor that drives an electricity generator. The electrical output from this renewable wave energy power plant is then connected to the electric grid via a subsea cable.
The WaveRoller technology provides three unique empirically validated benefits:
It is installed and operating in the nearshore area – easy access to site, protected from extreme conditions and minimized balance of plant infrastructure cost.
It captures power with a bottom fixed panel (oscillating wave surge converter) – highly efficient power capture, can operate in low-, mid- and high-sea states with no cut-off and with only one moving part.
It converts movement to electricity using an onboard power storage and hydraulic system – smooth and grid-compatible power output, ability to establish and support grid and low maintenance design with inverters on shore.
phenomenon
The surge phenomenon is a universal physical event that occurs when waves approach the shoreline. Waves in deep water are essentially water particles moving in a circular motion.
As waves approach the shore, they start “shoaling” as some of the water particles moving in a circular motion meet the seabed. This interaction with the seabed elongates the circular motion into a horizontal elliptic shape. This in turn amplifies the horizontal movement of the water particles in the near-shore area, creating a strong surge zone, which is the optimal location for WaveRoller.
WaveRoller technology is well positioned to replace environmentally unfriendly power sources with clean and renewable energy generated from ocean waves. Harnessed by WaveRoller, this blue energy source is not only more benign to the environment than fossil fuel technologies but it also poses fewer risks than nuclear energy and is on par with, or even superior to other renewable energy sources.
A WaveRoller does not produce any emissions during operation. Other emissions during its lifecycle, from building the devices to its disposal, are significantly smaller than those of plants powered with fossil fuels.
WaveRoller utilizes waves, which carry far more energy than wind in a site of comparable size. A WaveRoller provides about seven times more nominal power generating capacity than a wind turbine in a similar sized area.
Apart from its low space requirement, a WaveRoller device operates underwater and has a very low visual impact. The panel height is designed to minimize or completely eliminate its protrusion above the water surface, ensuring the preservation of the natural beauty of the sea and coastline.
WaveRoller follows the movement of the water, which makes it very friendly to the surrounding marine life. The hydraulic, mechanical and electrical systems are also fully sealed inside the WaveRoller hull, which protects the marine life from noise and other possible pollutants.
Ocean waves contain more energy than other renewables and are reliably frequent. Their power is on average 30-40 % less intermittent than wind and solar energy.
WaveFarms and wave energy devices can be ‘plugged-in’ and developed in parallel with coastal wind and solar projects to bolster a hybrid clean energy mix that is sustainable and secure for communities. The energy that is harnessed from WaveFarms is inserted into the electricity grid and used to power houses and buildings – commercial and residential.
It is a clean energy solution that is fully complementary to wind and solar power, and better supports the growth of renewable sources of energy.
AW-Energy operates a world-unique dry-land test facility for the WaveRoller technology in Finland. With the test facility, AW-Energy can make significant cost and time savings by being able to test and fine-tune PTO units in factory conditions, instead of having to carry out expensive and time-consuming ocean tests for each separate unit.
The WaveRoller Test Centre operates a wave machine consisting of a hydraulic piston creating the immense forces matching those of waves in the oceans. With torques of more than 3 MNm the wave machine feeds the WaveRoller Power Take Off system (PTO) with energy levels similar to real life conditions.
Stochastic wave conditions recorded anywhere in the world can be fed into the system allowing the wave machine to deliver identical input. With up to 2 MW of input power, the wave machine can simulate some of the most energetic wave conditions in the world.