Description
The project was gradually ended throughout 2017-18 as funding ceased. At present, the initially deployed 34 seabed-based units are still in place, and discussions are undergoing in order to keep them at the site as artificial reefs. No buoys are attached or have been since 2016. The following and updated text should, therefore, mainly be seen as historical information.
Seabased’s WEC uses a simple, ring-shaped buoy tethered by a steel and synthetic line to a power unit housed on the seabed and based on the technology developed at Uppsala University. As the waves rise and fall, the buoy pulls up and down on a cable attached to a linear ‘translator’ —a kind of rotor—that uses a permanent or ferrite-magnet system encased in stators to generate power.
Location
Skagerrak, North Sea, Swedish waters outside the municipality of Sotenäs and the town Smögen, ca 120 km N of Gothenburg, at approximately 50 m depth.
Licensing Information
A full-scale permitting process, including an Environmental Impact Assessment (EIA) and consultations, started in 2007 and in October 2009 an application was filed to the permitting body, the Environmental Court in Vänersborg. Final court negotiations took place in May 2010 and the permit was issued in July 2010. Seabased was responsible for and carried out the Environmental Impact Statement (EIS), including consultations, etc., for the whole permitting process. Due to unclear competitive legislation, under the EU, the project awaited clearance from the EU for one and a half years before the project approval and start was given, which halted the project for approximately 18 months. A large number (35+) of additional permits/consents/licenses, from various authorities, were also required in order to enable necessary pre-construction studies, the project start itself, and operation.
Project Progress
First phase, 1 MW (34 units), was completed in early 2015.
Second phase, up to 9 MW, was under negotiation during 2016-17.
The Sotenäs project was shut down, but the remaining generators were permitted to remain at site as a artificial reef no take zone for trawling.
Key Environmental Issues
Although the project area was chosen carefully, in order to minimize competing interests and conflicts without compromising with necessary siting requirements, the permit from the Environmental Court was conditioned with four “control programs” (post-construction studies) regarding the marine environment: effects on the Norway lobster population (also a very important commercial species in the area); (benthic) fish population and behaviour changes in relation to the wave power park; eventual changes in the seabed conditions and therefore also the benthic faunal community, and finally; underwater noise monitoring.
The only study eventually performed was on Norway lobster. During 2016-18 and 2020 test cage fishing was performed within the park area and two nearby control areas. Approximately 75 (225 cages in 2018) cages were used each year, and Norway lobsters were caught, measured (and some marked) before being released as near to the catch site as possible. During 2016-17 a ROV with video cameras was also used to aid in counting burrows of lobsters. The aim of this study was to determine the eventual size and density differences in lobsters between the park area (no-take zone) and the nearby control areas where trawling still was ongoing. Preliminary results of ROV studies are published in the AWTEC 2018 Conference Proceedings with the title “Effects of Wave Energy Generators on Nephrops norvegicus” (Bender & Sundberg 2018) and indicate that wave power sites may be beneficial for the number of Noway lobster burrows. Final results including all study years and sampling methods are currently under analysis (Bender et.al).
A by-product of the ROV data was the possibility to count and analyse densities of sea pens within the park area and the surrounding control areas (Bender & Sundberg 2019). Results indicate neither the presence of the wave power generators nor the restrictions for marine activities seem to have a noticeable effect on the two investigated sea pen species.
A survey of artificial reef fauna was undertaken with positive results before consent was given to leave infrastructure to support the artificial reef effect.
Environmental Monitoring:The purpose of the environmental studies to be undertaken at the Sotenäs wave energy park was to follow up expected, known possible stressors/receptors, follow up new findings, and with “new” monitoring techniques. The project was conditioned with four specific study/control programs considering eventual effects from: underwater noise, seabed changes, population alterations in (1) Norwegian lobster, and (2) fish in general within the project area. Seabased AB intended to conduct and be responsible for the monitoring with support from Uppsala University (coordinating) but also Swedish University of Agricultural Sciences and Gothenburg University, plus independent consultancy firms, foremost Marine Monitoring AB in Lysekil.
Environmental Webpage: https://seabased.com/ecosystem
Environmental Monitoring: Sotenäs Project
| Phase | Stressor & Receptor | Design and Methods | Results |
|---|---|---|---|
| Baseline | Changes in Flow Physical Environment |
Wave measurements Satellite data, during operation Datawell WaveRiderTM Buoy | |
| Baseline | Habitat Change Physical Environment |
General baseline information of benthos Sediment sample collection in wave park area and surrounding control areas | Completed Baseline information |
| Baseline | Human Dimensions | Marine uses/users. National statistics | |
| Baseline | Marine Mammals | N/A National statistics | |
| Baseline | Collision, Habitat Change Fish, Fisheries |
Population effects/trends Fisheries statistics | Completed Baseline information |
| Baseline | Birds | N/A National statistics | |
| Baseline | EMF, Habitat Change Invertebrates |
Norwegian lobster population effects/trends Fisheries statistics | Completed Baseline information |
| Post-Installation Monitoring | Collision, Habitat Change Fish |
Population effects/trends Passive sonar monitoring and complementary test fishing (nets, trawls etc.) | |
| Post-Installation Monitoring | Collision, Habitat Change Fish, Demersal Fish |
Population effects/trends Standardised test fishing – focus benthic fish | |
| Post-Installation Monitoring | Noise Fish, Marine Mammals |
Disturbance from underwater noise Hydrophone recording during different phases of the project (deployment, operation, maintenance etc.). | |
| Post-Installation Monitoring | EMF, Habitat Change Invertebrates, Fisheries |
Norway lobster population effects/trends - also some other benthic invertebrate species will be able to be included
ROV equipped with video camera on standardized routes within park and control areas. Also, application of baited Prawn creels (inside and control areas) |
Ongoing Two years of sampling performed (2016-17) within wave park area and control areas. At least two more years of sampling remain. |
| Post-Installation Monitoring | Habitat Change Physical Environment, Invertebrates |
Population effects/trends for benthos Sediment sample collection in wave park area and surrounding control areas | Ongoing Two years of sampling performed (2015-16) within wave park area and two control areas. At least two more years of sampling remain |
| Post-Installation Monitoring | Changes in Flow Physical Environment |
Wave measurements Datawell Wave RiderTM Buoy |