The Sotenäs project was a joint effort between Seabased, Fortum, and the Swedish Energy Agency.The Swedish Energy Agency awarded an investment grant to Fortum and Seabased for the wave power plant in February 2010.
Map of wave park in Sotenäs
On December 13th, 2015, Seabased and Fortum connected the Low Voltage Marine Substation (LVMS) to the Nordic grid in Kungshamn in what was heralded as the first ever grid connected subsea generator switchgear.
The installation of Seabased´s LVMS (Low Voltage Marine Substation) in Sotenäs
Shortly thereafter, the first four buoys were connected to their respective wave energy converters and on January 14th, 2016 the wave energy park generated electrical power to the Nordic power grid for the first time. The event received widespread international attention as the world’s first grid-connected multi-generator wave park.
The installation of buoys in Sotenäs
Based on the generation results from Sotenäs, coupled with what we have learned about cost control and installation during the project, we have been able to calculate that given a wave climate and installation conditions suited for the technology, Seabased should be able to deliver electrity to the grid for under 10 cents per kWh. This price makes the technology competitive in many areas of the world today, such as off-grid islands dependant on diesel generators.
Phase 1 of the Sotenäs Wave Power Project is now complete, and all the equipment included in it has been manufactured and installed. This includes 36 wave energy converters (WECs), a subsea switchgear (LVMS) and an almost 10 km long transmission link between the wave energy park and the mainland grid. Seabased also assumed responsibility for all permits, including environmental permits.
Overview diagram of Seabased´s wave energy system in Sotenäs
See also: Sotenäs Facts and Figures, Seabased Technology
Studies in advance of the project concluded that wave power could be a very competitive green alternative. The load factor, or the average percentage of power produced per MW installed, in the region was determined at approximately 23% for wind turbines. Seabased Wave Energy Converters (WECs) offer a much higher load factor of 55%
Research and Development within Seabased was carried out in close cooperation with researchers at the Centre for Electric Renewable Energy Conversion at the Ångström Laboratory, Uppsala University with full access and cooperation on MSc and PhD projects led by the founders of Seabased, professors Mats Leijon and Hans Bernhoff.
The actual generation results were significantly higher than anticipated at the start of the project, in part due to generator redesign. Because of the increased efficiency of the new generators, the 36 WECs suggest an installed capability up to 3 MW. The previous design would have rated the same number of WECs at about 1 MW. More on Generation Results
Manufacture and Installation
A great deal of effort went in to adapting the production of wave energy converters for efficient large scale manufacture. Parameters for choice of both materials and processes included series production quality control, cost-efficiency, environmental friendliness, and ease of manufacture.
The project also involved the testing of a number of different installation techniques. Installation using a specialized Light Construction Vessel (LCV) proved the safest and most cost-effective method, and allowed for more equipment installed and connected per trip. At an installation depth of 50 meters, the use of a ROV (Remotely Operated Underwater Vehicle) was preferable to using divers, for reasons related to. More on Manufacturing and Installation
With a full lifecycle (“cradle-to-cradle”) approach, the manufacture, installation and use of Seabased wave parks fulfill all of Sweden's 16 environmental quality objectives that relate to wave energy and contribute to the increased use of renewable energy with little or no emissions or adverse environmental impacts.
Emissions are minimal and limited to production and transportation; power production itself is zero-emission. All materials used are tested extensively and considered safe in subsea environments; in addition, they can be recycled. There are no underwater moving parts that could harm animals.
It is still too early to draw firm conclusions about how wave power affects the marine biological environment of the park area, but preliminary results from research indicates that the effects are neutral or positive for the marine environment. The installations of the wave power park create both an artificial reef and a protected zone for plant and animal life which can be likened to a marine wildlife reserve. More on Environmental Aspects
The Sotenäs project has been extremely valuable for Seabased, as it has demonstrated the potential of our wave technology to generate large amounts of power at low wave heights. This in turn, opens up huge new markets, from the Great Lakes in the United States to the tropics, where waves are relatively small and stable.
The results show that our technology is already quite competitive in many parts of the world, such as islands or other "off-grid" areas that depend on diesel-electric power. As the solution is modular, potential customers could be found everywhere from densely populated coastal areas with the ability to scale up to thousands of MW, to offshore installations, such as fish farms or oil platforms that only need a small number of generators for their operation. In addition, there will be opportunities for cooperation with other growing sea-based activities such as desalination plants or offshore wind farms.
Seabased will be therefore focusing its future efforts on commercialization. More on Next Steps