OES-Environmental distributes metadata forms (questionnaires) to solicit information from developers involved in environmental monitoring around marine renewable energy project sites around the world. This page provides project descriptions, baseline assessment, post-installation monitoring, and links to available data and reports. Content is updated on an annual basis.

Lysekil Wave Energy Site

Description

The project was started in 2004 and old consents did run until the end of 2013. A new round for permanent permits, and for an extended test site, was initiated in 2014 and was filed to the Environmental Court in December 2014. A 20-year permit was issued in June 2015 by the Environmental Court in Vänersborg. The new permit allows arrays of maximum 20 wave power devices, 2 substations, and land cables, plus related equipment.

During the first 10 years of the project a maximum of 10 generators was allowed to be deployed simultaneously, plus two submarine substations. Additionally, the project was/is allowed to use 30 smaller buoys, with foundations, for studies on environmental impact, and a surveillance tower for monitoring the interaction between waves and converters was installed on a nearby islet. At the time the research area holds one sea cable connected to a measuring station onshore and a Datawell Wave Rider ™ buoy for wave measurements. The measuring station is connected to the grid. The wave energy converters are based on a linear synchronous generator (with ferrite or permanent magnets depending on tests) which are placed on the seabed and driven by a heaving point absorber at the ocean surface. The converter is directly driven, i.e. it has no gearbox or other mechanical or hydraulic conversion system. This results in a simple and robust mechanical system and a sophisticated electrical system. As of 2024, more than 10 different generators have been tested.

Location

The Lysekil research site is situated on the Swedish West coast, about 100 km North of Gothenburg, near the municipality of Lysekil. The site is located 2 km offshore, between a northern (58º 11’ 85” N, 11º 22’ 46” E) and a southern navigational marker (58º 11’ 63” N, 11º 22’ 46” E) signalling the research area to avoid interference with shipping.

Licensing Information

During 2004–2011 the County Administration gave several necessary consents for ten wave energy converters, along with an additional 30 buoys for environmental impact studies. Special consents were needed, such as for the sea cable from the project area to the mainland grid at the nearby island of Gullholmen. All old consents ran until the end of 2013. At the end of 2014, a full-scale application was filed to the Environmental Court which was proceeded by a large number of consultations and full-scale Environmental Impact Assessment. Consultations with stakeholders involved local inhabitants, fishing organizations, local governments and the National Maritime Administration and were necessary in order to obtain the permits referred to above and thereby the use of the area. The new permit came into legal force in June of 2015 and lasts through 2034. It allows arrays of maximum 20 wave power devices, 2 substations and land cables, plus related equipment. The new permit allows for the use of an area of 0.5 km2 and will make it possible for external use of test site area. External users, however, will need consent from regional authority regarding equipment whereas the EIA can be used for area description, etc.

Project Progress

The establishment of the research test site has been done in several steps. The launch of the first wave power generator, including the sea cable to shore, was made in March 2006. The number of WECs deployed and active has varied over the years, depending on current research focus and funding. Several different contractors have been working within the project during the commissioning and decommissioning phases of equipment. Current permit ends in 2034.

Key Environmental Issues

The environmental studies have so far focused on marine organisms living in the seabed (the infauna), organisms involved in biofouling and on mobile fauna, mainly fish and more recently crustaceans. Reef effects directly after deployment of the devices/foundations have been assessed, and continuous investigations on long-term effects have recently been finished. A significant difference in number of edible crabs, even 12 years after deployment, between foundations with and without cavities is one of the findings, showing how habitat complexity can be applied on a low-cost basis (Bender et al. 2020). Focus has also been set on measuring underwater noise with extensive development of hydrophone equipment. A PhD program where sonars are developed and adapted for passive or remotely controlled underwater monitoring ended in 2019 (Francisco et al. 2022). Seabed mounted sonars have been found to aid in monitoring the abundance and behaviour of fish and marine mammals (harbour seals) in the vicinity of wave energy (and other marine energy) installations, being able to operate continuously and autonomously for longer periods. Cage fishing studies over a four-year period aimed to reveal the influences of the Lysekil research site on the abundance and size of local decapod species (Bender et al. 2021). 

The purpose of the environmental studies being undertaken at the Lysekil test site is to follow up expected, known possible stressors/receptors, follow up new findings, and develop “new” monitoring techniques. Also, and as a condition for the 20-year project, post-construction studies are required by the permit, and under the control of the regional authorities. Monitoring is being undertaken by Uppsala University, Department of Electric Engineering (former Engineering Sciences), Division of Electricity, and funded by various research foundations, utility companies, etc. So far, and a key finding, is that effects/impact by presence or operation of WEC’s is low and that positive effects in terms of artificial reef effects, FAD’s and no take zone (esp. crustaceans) also are important. Since 2020 there has been no active field research activities and for the next few years no additional environmental studies are anticipated.

For additional information on current research areas, view the wave energy research group at Uppsala University’s current research site here.

Papers, Reports, Research Studies

 

Baseline Assessment: Lysekil Wave Energy Site

Receptor Study Description Design and Methods Results Status
Invertebrates Infauna characterization: analysis of species composition Sediment sample collection inside the test area and in control areas.

A hap-score with a diameter of 14 cm was used. The sediment sample was filtered using a 1mm sieve and animals were removed and preserved in formalin. Diversity data (number of individuals, number of species and Shannon Wiener diversity) were compared with a one-way ANOVA. 		The sediment samples contain in total 309 individuals of 68 different species. There is significantly higher species abundance in the buoy area compared to the control area. This can be explained by the variety of sediment substrate: sediments in the test area contains both silt, sand and shell gravel whereas the control area contains silt and shell gravel. The biodiversity in sandy sediments with medium grain size is most often higher than in other soft bottom. For wave power devices anchored on soft sediments the type of sediment and infauna the area contains should be an important issue.

Polychaete worms were the most abundant species in the sediment and very small, juvenile organisms were found. There were no red listed species in those areas and thus no concern about extinction of sensitive local species arose from this study. 		Completed
Physical Environment Time series of wave elevations at the Lysekil research site continuously since April 2004. Wave climate. Datawell Waverider buoy - the measured spectrum has been used for numerical studies of the power capture capability of a cylindrical buoy. It has also been used to calculate the wave climate of the site. The average energy flux during 2007, excluding August, was 3.4 kW/m. While the most frequent sea state has a value for TE around 4 sec and HS less than 0.5 m, the main energy contribution comes from the more energetic sea states. Due to its relatively low energy flux, the wave climate at the Lysekil test site would not be ideal for commercial wave power production. Ongoing

Post-Installation Monitoring: Lysekil Wave Energy Site

Stressor Receptor Study Description Design and Methods Results Status
Noise Fish, Marine Mammals Investigation of eventual effects by wave energy converter generated noise Recordings over long periods by multiple hydrophone systems positioned on seabed Noise is generated, especially during higher wave states. Noise not regarded as a severe impact mainly as back ground noise is far loader. Completed
Habitat Change Fish Investigation of the effects of wave energy converters on macrofaunal species abundance in surrounding soft bottoms The succession of colonization patterns in different organisms was investigated. A reference site was selected and used for comparison. 9 core samples were taken both at the reference and the deployment site using a Hapscore sampler. Macrofaunal species were identified to the lowest possible taxon. Differences in biomass, number of individuals, species and diversity were most probably due to sediment transportation and hydrodynamic processes rather than biological processes. The deployment of WEC’s in the Lysekil site would rather have minor direct ecological impacts beyond the level of natural variances. Completed
Habitat Change Invertebrates Investigation of the succession of colonization patterns in different organisms. In the spring of 2005, 4 biology cylindrical buoys with a diameter of 1.8 m and a height of 0.8 were installed at 25 m depth on a seabed consisting of firm shell gravel and silt. They were moored with stiff lines to 10-tonne concrete foundations having a diameter of 2.8 m. The distance between the buoys were100 m to 300 m. An additional bigger buoy, with a diameter of 3 m, moored to a 40 tonne concrete foundation was also installed.

In the Spring of 2007, 21 additional bouys (ten of them without holes and eleven of them with various holes) were put in place with a distance of 15-20 m between each other. The succession of colonization patterns in different organisms has been investigated. 		Vertical structures were more colonized than horizontal ones but there was no significant difference between foundations with and without holes. The low light penetration was identified as the most probable cause of low biomass at the location. Completed
Habitat Change Invertebrates Decapod community effects/trends Application of baited Prawn and Lobster creels (inside and control areas). Four years of sampling performed (2016-19) within wave park area and control areas. Completed
Displacement Fish, Marine Mammals Development of seabed mounted sonar system for monitoring of marine mammals and fish. Data loggers and large battery system allow for recording up to several weeks, independent of weather etc. Single fish, or shoals, and seals are frequently, or are commonly recorded. Completed