Time to test wave power on a large scale
In Lysekil the foundation is being laid for Sweden’s first commercial wave power array. Wave power stations are being mass produced, based on many years of research at Ångström Laboratory. Now we’ll see whether the Uppsala construction can withstand the waves and storms and turn a long-term profit.
The proximity of the sea is immediate in the wave power factory at North Harbour in Lysekil. An open door lets in the sound of waves and the cries of seagulls. It’s the power from those waves that is to be harnessed and transmitted straight into electrical outlets.
The technology is provided by the company Seabased, a spin-off company from Uppsala University. They are to build a wave power array for the energy company Fortum, with partial financing from the Swedish Energy Agency. This autumn production will start on 42 wave power stations, to be finished by next summer. They will then be shipped to Sotenäs outside Kungshamn for underwater deployment out to sea.
Each station rests on a platform of concrete and has a line attached to a buoy that bobs up and down on the surface. It’s the up-and-down movements of the waves that is converted to electricity in a linear generator.
Wave power trials have been run in other countries, like Portugal and France. What’s unique about this model is that the “dirty” electricity that comes from the generator is converted to 50 hertz – the standard frequency in our outlets – in relays under the sea. The electricity is then sent via sea cable to land and straight to the grid.
When we visit the factory training is underway at the new laser machine used to cut steel. A bit further in Daniel Käller is working from high up, attached to a safety line in the ceiling. He’s assembling a translator, built of thin layers of magnets alternating with steel plates. When finished, it will weigh more than five tons and constitute the very core of the unit.
Daniel Käller is an assembler and previously worked with various research projects at Ångström Laboratory. Now he’s moving to Lysekil to work full time at Seabased. He worked with the prototype for several months, but now it will all go much faster. One unit a week will be assembled in the factory hall.
‘Things have to be done in an orderly manner in order for this to work’, says site manager Hans Hillerborn.
‘We’re trying to be as economical as possible with resources and produce as efficiently as possible, according to the concept of “lean production”. We assemble every part in a standardised and predetermined way.’
With a background with Saab in Trollhättan, he knows how important that is.
‘What we’re building has to work flawlessly for 20 years; the demands are high. We have to know that it doesn’t leak, that the welds are done properly and according to instructions.’
Just a few metres from the factory, there’s a quay, where the units will be shipped from. When the first 42 units have been deployed at the bottom of the sea, they will be tested for a period. Once the testing is completed and any tweaks have been made, a further 378 units will be manufactured. There will be a total of 420 units in Sweden’s first, and the world’s largest, wave power array.
Many years of research at Ångström Laboratory in Uppsala lies behind the units, led by Professor Mats Leijon. His unique system for wave power is based on calculations and simulations and has also been tested in reality outside Lysekil. Moreover researchers have evaluated the environmental impact and the marine biological and marine ecological aspects.
In 2001 Mats Leijon started the company Seabased, but it took the company some time to find funding to construct and test the technology on a large scale. Not until December 2011 did the EU approve partial financing with government funds, making it possible for a contract to be signed with Seabased, the Swedish Energy Agency, and Fortum.
Researcher Jan Sundberg at the Division of Electricity is among those who have followed
the project from the outset.
‘When I started in 2002 there were four researchers and two PhD students here. Now 90 people work at the Division, including 46 doctoral students.’
Besides wave power the Division also does research on marine current power, wind power, and electric vehicles. Wave power has made the most progress, but the field is far from exhausted, says Jan Sundberg:
‘No, just because Henry Ford started mass producing cars in the early 20th century, auto production didn’t stop developing. We’re going to be busy for a long time to come.’
There are many different parts that can be adjusted and tweaked, to improve efficiency
and increase profitability.
‘You might think that one per cent up or down wouldn’t make a difference, but if you consider how much money is involved, there’s a lot to be gained.’
Jan Sundberg sees two clear advantages to wave power. First and foremost it’s environmentally friendly. Research shows that wave power arrays can actually promote marine fauna by creating secure ‘reefs‘ where fish and crustaceans can find a safe haven from fishing vessels and other traffic.
‘Another great upside of wave power is that it has the potential to be profitable. It’s
possible to mass produce the equipment, and once it’s up and running minimal maintenance is needed.’
At the Lysekil factory industrial thinking will help improve the technology, perhaps mainly through efficient work modes and use of as little material as possible. But there are challenges, of course. The units are supposed to last for 20 years without maintenance at a depth of 48–52 metres. The construction also has to withstand high waves and storms.
‘It’s a matter of coping with the occasional high wave’, says Hans Hillerborn.
With the storm Gudrun fresh in our memory, it’s all about preparing the units to stand firmly on the ocean floor without needing repair for 20 years.
An exciting, indeed critical, period for wave power is just starting. The world is following what’s happening on the west coast with great interest. And researchers from Uppsala University continue to visit Lysekil frequently. They have a new unit underway to be placed in the sea autumn, at Islandsberg outside Lysekil.
‘It’s actually strange that we have made such progress on this marine technology here in Uppsala. But maybe it’s because we don’t come from a coastal city that we have been enthusiastic enough to keep working all these years’, says Jan Sundberg.
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FACTS/How it works
Wave power units, so-called linear generators, are deployed on the ocean floor. The units are connected with buoys on the surface that capture the kinetic energy of the waves, which is converted into electricity in the generators. The units, in turn, are connected to each other through underwater relays to a wave power array, from which alternating current can be supplied via a sea cable directly to the land-based grid. Source: Seabased
FACTS/The wave power array at Sotenäs
Together with the energy company Fortum, Seabased will set up Sweden’s first commercial wave power array outside Kungshamn/Smögen in Sotenäs Municipality. The wave power array will have an operational life of 20 years and is estimated to provide an installed output of 10 MW and comprise a maximum of 420 generators. Source: Seabased
Annica Hulth