As the deployment date for the full-scale Laminaria wave energy device approaches, Chief Executive of the Belgian wave energy company Laminaria, Steven Nauwelaerts, shared with us the latest information on the current status of their device, as well as the next steps leading to its commercialization.
Laminaria’s wave energy device falls under the attenuator type of wave energy converters, and is constituted from vertical surface that interacts with the incoming horizontal wave energy.
As a result of the horizontal movement in the water, Laminaria’s device is subjected to tilting and translational motion, which is transferred through the mooring ropes to the generators which produce electricity.
However, this device boasts another feature representing its ‘unique selling point’ as Steven Nauwelaerts puts it – that of integrated energy regulation. What this means is that the device can adapt to waves with significant difference in height, such as those found in stormy conditions, while maintaining both the steady energy production and the safety of the entire system.
Over the past years, Laminaria has been working with the European Marine Energy Centre (EMEC), INNOSEA, Ghent University, and Tension Technology International (TTI) on the technology development of the device under a project dubbed LAMWEC, which was partially financed through the EU-funded Oceanera-Net program.
The scaled version of the device was tested in real-sea conditions in the North Sea, while last year, Laminaria conducted tank tests with INNOSEA, which according to Nauwelaerts, proved the integrated energy regulation capabilities of the device.
“The device has a built-in algorithm regulating the height in the water column and it can in any sea state determine the maximum load on the device. Whenever the wave height exceeds what we need, the device senses that the loads in the mooring lines are adding input torque, or that the production of power is going up outside the predetermined range programmed in the algorithm, reacting accordingly by adjusting the position of a device in the water column.
“If there is too much energy present in the sea state, it would lower the height in the water column and therefore decrease energy exposure of a device. It is an ongoing process that happens incrementally – whenever the loads or parameters go up out of range, the device is lowered, and every 10 minutes it is checked if there is enough energy to produce nominal power. If not, it allows the device to resurface.
“The energy production stays steady, and also the loads on the mooring lines on the power take-off (PTO) system, and on the entire structure. It’s actually not only keeping the energy production steady, but all the mooring lines, anchoring, and PTO beneath a chosen threshold. This is unique to wave energy that we can regardless of the sea state choose the maximum threshold of the loads that we want to endure,” said Nauwelaerts.
In addition, the testing prompted Laminaria to build a slightly bigger device than originally planned for the EMEC deployment in order to increase the energy production.
“That was the second thing that was shown from the additional tank testing and intensive data analysis with INNOSEA. Based on their studies we have scaled up the device by 18%. The reason behind the decision is that by upscaling the device by just 18% we can increase the efficiency in capturing the energy of the waves known as capture width,” Nauwelaerts confirmed.
(Photo: Laminaria; INNOSEA)
The deployment at EMEC was backed by another EU-funded program called FORESEA in November 2016, which provided the operational support by funding some of the operational costs. The full-scale Laminaria device could hit Scottish waters in the late summer this year, at the earliest, Nauwelaerts said.
“We’re still working very hard to get the device at EMEC in late summer, so we want to deploy before late year storms start – but it is going to be tight. In worst case, we will be deploying at March 2018, after the winter season. We are still on schedule to deploy in September this year, however, we are very much aware that if we run slightly behind schedule, we will hit the winter weather and it’s probably more advisable to put off deployment until the spring time next year.”
The device at EMEC will be deployed for one year in order to have one full winter of operation, Nauwelaerts said, adding that one of the main reasons Laminaria is testing at EMEC is to prove the survivability of the device at even the worst storms, for which EMEC offers a suitable testing environment. Furthermore, Laminaria plans to tap into Orkney’s marine renewables supply chain to conduct the installation of the device.
“We are talking to two local marine operators, Green Marine UK, and Leask Marine, because we want to use the local marine operators as we consider it invaluable to have an operator with local knowledge especially for the first deployment. Also, both of the mentioned marine operators have experience in deploying both tidal and wave energy devices.”
The device destined for EMEC is currently in the early stages of construction with most of the work being done in Belgium. However, one of the most important parts of Laminaria’s device, the mooring lines, are being built in the UK.
“The mooring lines have threefold function – first of all, the sea keeping; second, to drive the PTO; and third, for energy exposure regulation for the height of the station. The work on the mooring lines is currently being done in Scotland and England where TTI, Marathon Belting and DSM have the first full scale rope samples woven. They are currently on a test bench at the laboratories of TTI,” noted Nauwelaerts.
The device to be deployed at the grid-connected wave test site at Billia Croo at EMEC will produce about 600MWh of power per year, Nauwelaerts predicts, adding that with that same device the energy produced yearly could range from 1500MWh to 1900MWh at the more exposed sites such as those found in the Outer Hebrides, also known as the Western Isles, in the UK, or at the sites in the west coast of Ireland.
So far, around €800,000 has been invested for the full development of Laminaria’s technology up to technology readiness level (TRL) 6, with additional budged for the 3-year project trialing the full-scale device reaching just under €3 million, Nauwelaerts revealed.
As the next step for the company, Laminaria is considering to do the first commercial demonstration project of 5MW that would feature between 14-17 devices, possibly in Ireland, or a smaller roll out at EMEC first, Nauwelaerts said.
“One of the sites in Ireland that is of interest to is the Atlantic Marine Energy Test Site (AMETS), located west of Belmullet, Ireland, which is being jointly developed by EMEC and SEAI. Our current shareholders are willing to provide the investment for the first commercial demonstration project in order to get the project bankable and insurable.
“Usually the shareholders don’t invest in the technology, as they are more interested in project development rather than technology development, but they are very keen on exploiting our technology. Their aim is to eventually develop wave parks that would use Laminaria’s wave energy technology,” concluded Nauwelaerts.
Interview prepared by Amir Garanovic