“The most dangerous thing that you could have when it comes to wave energy sector is skepticism. That is, probably, my greatest concern when it comes to UK market,” Mr. Ulf Lindelöf, CEO of Waves4Power said in an interview for Tidal Energy Today.
Lindelöf spoke about his company’s latest achievement, the recently deployed WaveEL wave energy device at Runde wave energy test site off Norway, as well as the issues this emerging renewable energy sector is currently facing.
The device, which was deployed in February this year and has since successfully weathered several storms, with waves reaching heights between 12 and 15 meters and wind speeds above 25 m/s, is beginning to prove its expected operational and endurance capabilities, Lindelöf said.
The installation of the buoy itself went smoothly, but the company faced delays with the launching of the system, due to unexpected equipment damage.
“During the launch of the connection hub a misplacement of a mooring line was discovered which required corrective action. The hub and its anchor was recovered to fix the mooring line and during this operation the connection hub was damaged and could not be relaunched without prior repair. The repair has started and the relaunch of the connection hub will take place as soon as possible. The wave power device itself works perfectly well and it is operational now, but we need the cable connection to shore in order to start pumping electricity to the power grid and that still has some delay.”
The working principle behind the WaveEL wave energy device, put simply by Lindelöf, is similar to that of a bike pump.
“We have the water column that is standing still in the long vertical tube. We use that as a counterweight to the movement of the buoy. As the buoy moves up and down the water column is acting on a water piston placed in the tube. The piston in turn is connected – via a piston rod – to a hydraulic pump (the ‘bike pump’), which creates a tremendous hydraulic pressure. The pressurized oil is passing through an accumulator from which the oil flows to a hydraulic motor driving the generator. The benefit of the accumulators is to smooth any power spikes resulting in an even, high quality electricity output from the system.”
The electricity is converted to 50 Hz onboard the buoy itself, after which it’s delivered as 490 V to the connection hub, where it is transformed to the right voltage for the power grid – in Runde’s case to 22 kV – and transmitted via sea cable to shore, ready for usage.
When it comes to the rating of the WaveEl wave energy system, Waves4Power is aiming at producing 250,000 kWh per year for the grid using the Runde buoy, Lindelöf revealed.
“The system itself will produce more energy, but we have losses during the energy transfer. We are also planning to make improvements in the control system during the test phase, so we expect to improve the output from the system to 350,000 kWh during the demonstration period. The system and its function we’re very confident about, but we believe there is potential to improve the control system to get more energy out of it. We’re working to optimize the output from the buoy in different wave conditions so we can extract more energy out of the system. That’s the research we’re going to undertake during the Runde project and we expect to achieve a 30% improvement.”
WaveEL wave energy device at Runde test site (Photograph courtesy of Waves4Power AB, Sweden)
When asked about the best approach for commercializing the wave energy sector, Lindelöf said the best way to go is step by step – building array structures to stimulate construction of larger wave energy parks, which could consequently lead to full commercialization.
However, the company has no intention of expanding the Runde demonstration project with additional buoys, but is looking at the European Marine Energy Centre (EMEC) in Orkney, UK, where it has plans to deploy an array of wave energy devices, as well as Norway for other applications.
“At EMEC we are looking at deploying a partial array – of say 10 buoys – in order to simulate what the full park would look like. In parallel, as an alternative, we’re working together with the Norwegian authorities and companies to look at the possibility to power fish farms off the Norwegian coast.”
Waves4Power’s Chief Executive added the company, for the time being, sees Norway as a very promising market for off-grid applications, and the UK for grid application for their wave energy system.
Nevertheless, Lindelöf drew attention to the growing doubts in the UK wave energy sector development, characterizing the current UK view on wave energy sector as ‘optimistic skepticism’.
“That is maybe our biggest concern. We do understand that in the UK there has been a number of failures for big, high-profile projects and there’s skepticism, and I think that is the most dangerous thing you can have particularly in the UK right now.
“The wave energy companies that have failed in the UK in the last year or two present a part of the evolution process and I think that should not stop UK from being in the forefront. I think that’s important.
“In my opinion, the UK has a very well developed test site system, Contracts for Difference (CfD) system which is an excellent way of promoting success, and everything in place to have wave power deployments in the UK, but there is reluctance or skepticism. That’s why we need to prove this properly, and we will do that. However, this skepticism, which we don’t see in Norway to be honest, might prevent us from coming to EMEC,” concluded Lindelöf.
Interview prepared by Amir Garanovic