QED Naval’s Subhub technology is a submersible, gravity based, foundation platform that can support and array of generic tidal turbines in either vertical axis turbine (VAT) or horizontal axis turbine (HAT) configuration. Subhub aims to reduce the cost of deployment of tidal turbines by installing an array of tidal turbines in a single offshore operation using small, low cost support vessels.
The Subhub’s ballast system provides an alternative to large, heavy-lift or specialised support vessels used to install and retrieve tidal turbines. With its submerged stability characteristics, the SH-CD design includes neutral ballast tanks that are flooded to sink the structure and firmly anchor to the seabed during operation. Once fully ballasted on the seabed, Subhub can produce power on the first tide. The Subsea Manifold is essentially a remote control unit for the Subhub installation and retrieval operations. It is designed to be easily deployed and retrieved from the seabed where it lies most of its life in service. The manifold enables all the ballast and data systems to be connected directly into the Subhub. The Crossbeam supports an array of up to three tidal turbines.
The SubHub Community Demonstrator (SH-CD) is the smallest version in the Subhub range that supports up to three sub-100 kW turbines to provide a total power output between 150 – 300 kW. The SH-CD serves the community-scale market, typically remote island diesel replacement market, with enough energy to power a community of around 50 – 80 homes. The SH-CD design was built in accordance with Det Norske Veritas Germany Lloyd’s (DNV GL) standards and is currently situated within Strangford Lough in Northern Ireland for testing on the performance of its ballast system. To date these trials have demonstrated the Subhub’s seamless installation and recovery process.
Located at QUB tidal test site, Castle Ward Bay in Strangford Narrows.
The Department of Agriculture, Environment and Rural Affairs (DAERA) Marine and Fisheries Division carries out licensing and enforcement functions in Northern Ireland territorial waters, under the Marine and Coastal Access Act 2009 (MCAA) Part 4. Other institutions involved in the process include the Northern Ireland Environment Agency. QED Naval’s marine licence application was received at DAERA in August 2017. A Variation Licence was issued 1 March 2019 which was valid until 29 February 2020.
Regarding the environmental legislation, wildlife licenses were required under The Conservation (Natural Habitats, etc.) Regulations (Northern Ireland) 1995 (as amended) and under the Wildlife (Northern Ireland) Order 1985 (as amended) for any operations which might impact on national and European Protected Species.
The SubHub Community Demonstrator project is largely funded through private equity investors from Kelvin Capital. However, the Scottish Investment Bank (SIB), has a minor share in the company. QED Naval have been collaborating with Queen’s University Belfast (QUB) and the Centre for Advanced Sustainable Energy (CASE), part of Invest Northern Ireland’s £10m centre for industry-led sustainable energy research. This collaboration has led to the deployment of Subhub in Strangford Lough at the QUB tidal test site in January 2019. The same month, Subhub was approved and certified by the Marine Coastguard Agency for towing operations.
In February 2019, Subhub was set up to undergo the initial ballast and flow augmentation trials that started in May 2019 for a period of three months in the sheltered Castle Ward Bay. The ballast trials were successful, with no other moorings required during deployments/retrievals and the self-installing platform with the single offshore operations completed in less than 15 minutes. The Subhub installation method is very directionally stable and self-aligns with the flow.
Since June 2019, QED Naval is closely and actively collaborating with local community groups such as Portaferry Past and Future. QED are currently raising funds for the next stage encompassing long term submergence trials to build on the Operations and Maintenance strategy. QED naval also intends to conduct performance trials and validate grid energy yield. It has recently completed the acquisition of 3 Tocardo, T1 tidal turbines to validate their modelling software TWEET (Tidal and Wave Energy Evaluation Tools).
QED Naval is a partner in the Interreg Tidal Stream Industry Energiser (TIGER) project running from 2019 – 2023. QED’s TIGER project is supported by a £3m European Regional Development Fund grant and will validate the performance of their SH-CD device and costs of deployment, operations and maintenance. QED will also start the development of the 2nd generation Subhub technology at Industrial scale with an output of between 600kW and 1.2MW.
Key Environmental Issues
- No significant ornithological issues associated with the project detected from the Northern Ireland Environment Agency (DAERA, 2019).
- No objections to the proposed development from the Inland Fisheries division from DAERA (DAERA, 2019).
- No issues or concerns raised from an aquaculture/sea fisheries aspect from the Sea Fisheries division from DAERA (DAERA, 2019).