The coastline of west Wales offers a powerful and consistent natural wave energy resource. This feature attracted Bombora to set-up its European operations at Pembroke Dock in 2017. Bombora is committed to developing a visually and environmentally “low impact” renewable wave energy converter. After the successful testing of their small and medium scale prototypes, and with the support of local and specialist suppliers, Bombora’s team are currently designing and fabricating a full-scale 1.5 MW mWave prototype in Pembrokeshire. This project will be the first in-water test of the full-scale device mWave device.
mWave will be positioned at East Pickard Bay, approximately 1km from Freshwater West beach in West Wales. The device has a communications cable which sits on the seabed running from the device to shore at East Pickard bay. The cable will run to an on-shore control station, screened from view, which sits 275m from the coastal footpath.
The project is consented with a Marine Licence and Onshore Consent from Natural Resource Wales, Planning permission from the Pembrokeshire Coast National Park Authority, and a Decommissioning Programme from the UK Department of Business, Energy and Industrial Strategy.
The project test plan involves installation of the mWave wave energy converter in August 2021, operation for 6 months, after which it will be fully decommissioned.
Key Environmental Issues
The key environmental issues, as described in the Non-Technical Summary, include changes in coastal processes, underwater noise, benthic ecology, impacts to protected and commercially important species (Atlantic salmon, edible crab, lobster, brown crab, whelks, bass, haddock, harbor porpoise, dolphins, minke whale, grey seal, Atlantic puffin, razorbill, guillemot, and kittiwake), and cumulative effects.
Papers, Reports, Research Studies
- The full Environmental Statement can be provided on request from firstname.lastname@example.org
- Bombora Wave Power. (2019). mWave Marine Energy Device and Onshore Infrastructure Environmental Statement: Non-Technical Summary.
Baseline Assessment: Bombora mWave Demonstration Project
|Receptor||Study Description||Design and Methods||Results||Status|
|Marine Mammals||Underwater noise assessment||Calculation of noise from installation and operation and comparison to species injury levels.||The noisiest activity will be the cable laying vessel. The results showed that for a range of marine mammal species they could be injured from the effects of noise within 0m-50m of the cable laying vessel (if they stayed for 24hours) or disturbed (could hear works) within a 2-7km area. |
Operational noise data is not available yet. A worst case assessment was undertaken using data from other marine energy devices. The results of the assessment showed that marine mammals would have the potential to be injured within a 3m-76m area from the device if they stayed for 24 hours, or they could be disturbed (hear the device) within a 0.5km to 7km area.
|Marine mammal baseline data review.||Desk study.||According to sightings data, harbour porpoise, bottlenose dolphin, short-beaked common dolphin, Risso’s dolphin, minke whale and grey seal are expected to occur intermittently, in low numbers. Grey seals are considered most likely to occur around the northern headland of the Milford Haven Waterway or within the Waterway. |
It was concluded that whilst there would be some increase in underwater noise and potential for collision risk, and therefore accidental pollution as a result of increased vessel numbers, the effect would be limited and not significant due to the scale of works. Notwithstanding this, measures will be put in place during offshore works to further reduce the chance of an incident resulting in accidental pollution or the potential for spread of alien non native species.
In terms of collision, through the design of mWave, there are no moving parts or mooring ropes to hold the device in place, which may affect marine mammals.
The potential for cumulative effects arising from the proposed project, in association with other projects was assessed. In conclusion, due to the limited size of device and the temporary nature of deployment the impacts of the mWave project activities on its own or in combination would be minor and not significant in EIA terms. A screening of transboundary impacts (effects across other EEA states) has been carried out which has identified that there is no potential for significant transboundary effects with regard to marine mammals from the project.
|Fish||Noise assessment.||Calculation of noise from installation and operation and comparison to species injury levels.||The noisiest activity will be the cable laying vessel. Fish could be injured in 1 - 3m of work and disturbed in 7m - 21m. All works on site would not occur for 24 hours continuously and the overall duration of installation is short (a few days). |
Operational noise data is not available yet. A worst case assessment was undertaken using data from other marine energy devices. The results of the assessment showed that for
fish the 24 hour injury area would be 0m-4m with disturbance in a 6m-78m area.
|Fish||Environmental Impact Assessment - fish study.||Baited remote underwater video: fish survey- Baseline informed through data collection Survey – Baited Remote Underwater Video deployment near the site.||The fish species in the area were found to be predominately demersal species (living close to the seabed), including flatfish and elasmobranchs, with migratory fish species, such as Atlantic salmon, lamprey and shad which move to the Waterway which is some 3.5km to the north west. |
Due to the fact that the installation of mWave does not require any site levelling or piling, with the device just placed on the seabed using minimal numbers of vessels, the temporary impacts for the installation and decommissioning were deemed to be of negligible to minor adverse significance (not significant in EIA terms). For operation, as there are no moving parts which may impact on fish, and the size of mWave is small in comparison to the available habitat, all impacts were deemed to be of negligible to minor adverse significance (not significant in EIA terms).
|Birds||Environmental Impact Assessment - bird study.||Desk study.||The marine ornithology chapter of the EIA identifies a range of seabird species as marine ornithology receptors including Atlantic puffin, guillemot, razorbill, gannet, kittiwake, shag, cormorant, brent goose, diving ducks (scaup, red-breasted merganser, common scoter) and divers (red-throated diver and great northern diver). Atlantic puffin, razorbill, guillemot, and kittiwake are notified interest features of the Skomer, Skokholm and the seas off Pembrokeshire/ Sgomer, Sgogwm a Moroedd Penfro Special Protection Area (SPA). |
Potential for displacement and disturbance to occur to coastal birds, or increased risk of collision as a result of an increase in vessel traffic, during installation and operation was assessed. Due to the short times scale of any works on site, and the limited number of vessels required the significance of the disturbance effects was assessed as negligible to minor (adverse).
In terms of increased risk of collision to sea birds who may dive into the water to catch fish, as for marine mammals and fish, the design of mWave means that there are no moving external parts. As such the risk of collision was considered to be negligible.
Accidental pollution may affect sensitive birds, either by resting on the surface the sea or diving to forage. Any offshore works will be undertaken in good sea conditions with a limited number of vessels as such the risk of accidental pollution is minimal. Notwithstanding this, measures will be put in place during offshore works to further reduce the chance of an incident resulting in accidental pollution.
Cumulative impacts upon marine ornithology from the mWave project have been considered together with the impacts predicted to arise from other projects in the area. Overall, the cumulative impacts on marine ornithological interest and designated features of nature conservation sites will be of negligible to minor adverse significance (not significant in EIA terms). Finally, a screening of transboundary impacts (effects across other EEA states) has been carried out which has identified that there is no potential for significant transboundary effects with regard to marine ornithology from the project.
|Invertebrates||Environmental Impact Assessment - invertebrate study.||Literature review, drop down camera video survey, and baseline data collection.||Due to the limited extent of the mWave project, the short duration of activity and the limited number of vessels required, the predicted effects on benthic species, including those associated with designated sites, was of negligible or minor adverse significance (not significant in EIA terms). Decommissioning activities are predicted to have the same effect as installation. |
The operation and maintenance of the mWave project may affect the marine ecology through the presence of mWave and associated cable on the seabed resulting in temporary habitat loss (up to 18 months) or through operation and maintenance activities possibly facilitating the introduction or spread of alien non native marine species. These impacts are predicted to result in effects on benthic receptors and designated features of nature conservation sites of negligible or minor adverse significance (not significant in EIA terms).
Cumulative impacts upon benthic subtidal and intertidal ecology from the mWave project have been considered together with other possible projects in the area. In conclusion, due to the limited size of device and the temporary nature of deployment the impacts of the mWave project activities on its own or in combination would be minor and not significant in EIA terms. A screening of transboundary impacts (effects across other EEA states) has been carried out which has identified that there is no potential for significant transboundary effects with regard to benthic subtidal and intertidal ecology from the project.
|Physical Environment||Wave and current assessment.||Grab sampling – Particle Size; Distribution of deployment area; 3 month ADCP Current velocity collection; 3 month ADCP Wave collection; Hydrographic Survey of deployment site (Multibeam Echosounder, Side Scan Sonar and Sub bottom Profiler)||The assessment found that due to the simple installation method, with no need to prepare the seabed, and with mWave and the cable being placed on the seabed, there will be very little sand disturbed. Any that is disturbed should settle. Only minor changes may be seen in the seabed sand transport as a result of the project due to the open bay location and relatively quickly. |
In terms of changes to sand movement or currents, the device footprint is small and due to its alignment there will be little change, with any change being in the immediate vicinity. The device will result in a local reduction in water depth. Due to this, during major storms some waves may start to break over the area of the device, but as soon as they pass over they will return to background levels.
|Human Dimensions||Marine archaeology baseline assessment.||Desk study.||The marine archaeology chapter identifies the likely effects of the proposed development on heritage assets within the mWave site as well as for an appropriate area around it. There are no statutorily designated assets, such as designated wrecks, within the mWave project site and there are no designated heritage assets within the vicinity of the offshore works. There is one scheduled monument, West Pickard Camp located on West Pickard Bay headland approximately 100m to the west of the cable landfall at East Pickard Bay. This would not be affected by the project. |
The offshore area encompassing mWave and the marine cable route have a medium potential for archaeological deposits dating to the early Prehistoric, post-Medieval and Modern periods. There is high potential for deposits dated to the post-Medieval period, specifically associated with a wreck, believed to be the Highland Home which is about 1.5km from mWave deployment site. The offshore area encompassing mWave and the marine cable have negligible potential for archaeological deposits dating to the Roman and Medieval periods. Where these archaeological deposits survive, they would be of local to regional significance. There is a landing craft gun which is mapped approximately 1.5km from mWave and is a Protected Place under the Protection of Military Remains Act 1986.
A number of potential impacts on maritime archaeology, associated with the installation, operation and maintenance, and decommissioning of the mWave project, were identified. These impacts included disturbance of sediments, buried prehistoric deposits, or archaeological resource (including shipwrecks), as well as increased sediment deposition on the seabed. Assessment of all these impacts results in effects of either negligible or minor adverse significance.
|Human Dimensions, Visual Impacts||Seascape and Landscape Visual Impact Assessment.||Desk study.||The Seascape and Landscape Visual Impact Assessment (SLVIA) assessed the effects on visual amenity of the mWave project from three locations within the 5km study area, which are listed below: |
• Viewpoint 1 – Hill Fort, South West of the Site
• Viewpoint 2 – Wales Coast Path
• Viewpoint 3 – War Memorial, B4319
Effects on visual amenity during the installation and deployment, and decommissioning phase would be restricted to locations within close proximity of the site, including the Wales Coast Path. At close proximity, the movement of vessels within the water will be visible, although the movement of vessels is an existing common feature within this part of the sea. Work to the site entrance, which is located on the B4320 may also be visible, as will the installation of the onshore control station and the laying of the marine cable. Any effects will however by short in duration and restricted to a very small proportion of the total study area.
Locations within the study area where the onshore control station will be visible are likely to be significantly restricted by local landform and vegetation such as hedgerows and trees. Therefore, from the majority of the study area it is predicted that the onshore control station will not be visible.
Effects on visual amenity are not predicted to be significant from all three viewpoints.
Post-Installation Monitoring: Bombora mWave Demonstration Project
|Stressor||Receptor||Study Description||Design and Methods||Results||Status|
|Collision||Marine Mammals||Monitoring cameras will be installed to view from the PTO down the mWave membranes. In clear water this can be used to view the interaction of fish and marine mammals with the device.||NA||NA||Planned|
|Collision||Fish||Monitoring cameras will be installed to view from the PTO down the mWave membranes. In clear water this can be used to view the interaction of fish and marine mammals with the device.||NA||NA||Planned|
|Noise||Marine Mammals||Monitoring will be undertaken during operation to collect underwater noise data for mWave.||NA||NA||Planned|
|Noise||Fish||Monitoring will be undertaken during operation to collect underwater noise data for mWave.||NA||NA||Planned|
|Changes in Flow||Physical Environment, Sediment Transport||Scour monitoring will be included in Environmental Management Plan.||NA||NA||Planned|
|Changes in Flow||Physical Environment, Water Quality||Implementation of Marine Pollution Contingency Plan to manage risk of accidental pollution.||NA||NA||Planned|
|Changes in Flow||Ecosystem Processes||Invasive species risk assessment.||NA||NA||Planned|