Subhub Demonstration Trials Begin

QED Naval have completed the setup of the performance trials of the ballast system of the Subhub Community Demonstrator. The trials will take place over the next 3 months, initially situated at a sheltered water, low flow site in Castle Ward Bay. The conditions will be progressively increased in magnitude by moving offshore into deeper waters and higher flow rates.

QED Naval are being assisted by Cuan Marine who will conduct all the marine operations using the their 10m Multicat called “Cuan Cat”. Using this modest but highly effective work boat keeps the costs down. Cuan Marine are also providing a test barge for the Subhub Ballast Control Centre (BCC) and Subsea Manifold.

Subhub is unique in the manor in which in installs/recovers subsea equipment. It is more stable in the submerged or dive condition than it is in the transit condition. The net weight which causes the Subhub to dive is relatively small between 1 -10tons so the dive can be controlled easily and recovered quickly to the surface, within minutes.

Subhub has already proved itself in the transit condition having been deployed from Belfast to Strangford Lough which involved a passage ranging 50nm offshore in near gale conditions experiencing a sea state in excess of 2m in significant wave height.

Subhub has spent that last 3 months at sea experience the winter storms and freezing temperatures and it is clear that Subhub is coping well in its new habitat. There is 100% availability on all ballast systems and instrumentation which is testament to the design and quality of supply chain equipment.

However, it is clear that in the transit condition, floating at the surface, Subhub, like any marine structure, attracts significant marine fouling. This is a result of being at the surface in a relatively benign flow environment in pristine and fertile waters.

QED Naval have planned maintenance two times a year (April and October) to deal with the marine fouling issue and this plays to the Subhub’s strengths that it is easily and cheaply recovered for servicing the turbines and electrical equipment and maintenance of the hull structure. This may be reduced to once a year as the company learns more about the O&M requirements.

Setup of Cuan Marine’s barge to support ballast system and performance trials.

Subhub, umbilical and subsea manifold all secured on the mooring ready for installation/recovery.

Canadian Patent Granted for Subhub

QED Naval’s Canadian patent application (2837613) for the Subhub tidal platform has recently been granted. It covers submersible apparatus and methods of installing anchoring equipment and refers to the hydrodynamic impacts of the Subhub.

With this award of patent and the validation data from the technical demonstrator, QED Naval are looking to exploit the Subhub technology and market in Canada. QED Naval are keen to forge relationships with Canadian stakeholders within the tidal, shipbuilding and fabrication sectors including energy companies, project and infrastructure developers, and marine operators.

The key features of the Subhub are:

  • It supports all the requirements of an offshore tidal power plant and enables the fully integrated platform to be towed offshore using low costs tugs or work boats.
  • Once on site it uses its patented submersible, self-installing and recovery methods, again using low cost installation vessels in a single, quick offshore operation.
  • Its hydrodynamic form accelerates the flow into the turbines significantly increasing capacity factors and energy yield. It also generates down-force to reduce the amount of solid gravity based ballast.

These key features of the Subhub technology provide a step change in the Levelised Cost of Energy of tidal systems which enables communities to manage their own assets as well as utility scale systems to compete with offshore wind.

If your organisation have an interest in partnering and utilising Subhub technology in Canada, please contact Andrew Smith (no relation) at andrew.smith@dejablueconsulting.com. Or if you have any technical queries regarding the technology please contact Jeremy Smith at jerem@qednaval.co.uk.

Subhub’s arrival at the mooring in Castle Ward Bay after overnight offshore passage from Belfast Harbour.

Subhub Ready for Ballast Trials

QED Naval returned to Subhub following the completion of the tow on a cold but bright winter’s morning to tidy things up and secure Subhub for the initial ballast system and flow augmentation trials.

The moorings were re-set so that Subhub now aligns to flow on the flood and ebb tides where flow speeds of up to 1m/s are experienced which is ideal for conducting the initial ballast system trials.

Some of the marker buoys were reset and the umbilical and operations tether unraveled and stretched out. The umbilical allows the remote control of the Subhub platform from the support vessel which is a barge in this case.

The  video below you can see the umbilicals are tough outer pipe used to protect all the service lines to operate the Subhub remotely.  The service lines are further protected by bundling them into a tough PE coating . The service lines include:

  • Hydraulic lines to control the seawater inlet and tank vent valves;
  • Low pressure air to pressurise the tanks to deballast all the seawater which provide the required on-bottom weight to overcome all the wave and tidal forces;
  • Data/coms cable for monitoring the Subhub and control the operational condition of the Subhub;
  • Main export power cable.

The umbilicals are connected into the Subsea Manifold which is an subsea junction box so when the Subhub is installed all the services can be disconnect from the support vessel housing the air compressors, HPU, generators and control panels. It can then be lowered to the seabed so the support vessel can demobilised and site cleared of any visual impact. Equally, the Subsea Manifold can be easily retrieved and the systems connected up to take control of the Subhub again.

The video below also shows the final action of the day which was to make some modifications to tidal turbines. Supported by Cuan Marine’s small multicat, Cuan Cat, it made for easy access to the tidal turbines.

Subhub on its  mooring at Game of Thrones, Winterfell Castle.
Operations Manager on the top deck of Subhub with easy access to all systems.
Subhub sloping top deck used to access the Subhub and mooring lugs which double as lifting lugs used for the launch.
Full systems trials onshore with all the service lines connected to simulate installation and recovery of the Subhub.

 

Subhub Deployment to Strangford Lough

In mid January Subhub successfully completed the 50 nautical mile offshore passage from Belfast Harbour to Strangford Lough. The final stage of the departure was the approval from the Belfast Harbour Pilots.

The Pilot brought together all the contractors who included: Ian Coleman from Inyanga who were contracted as towing agents. Also included were the skippers of MTS Taktow, as the main tow vessel,  Ferran & Sons Farset as the rear tow vessel and the licensed operatots to handle the mooring lines on the D1 quayside. Final clarifications and adjustments were made with the departure plan and then the Pilot took control from that point forward.

Jeremy Smith, QED Naval’s Managing Director said:

“We are delighted with the performance of the Subhub during the deployment, which was not without its challenges, namely, the weather. The conditions experienced offshore reached 30 knot, near gale, wind gusts and over 2.0m significant wave height so they were far from ideal but underlines the capabilities of Subhub tidal platform and the commercial benefits and operational availability of this installation and recovery method for the through life support of tidal turbines”.

“The collaboration with Inyanga Tech as towing agents, Ferran and Sons and Cuan Marine worked very well and I wouldn’t hesitate to use them again”. 

Richard Parkinson, Inyanga’s Managing Director said:

“The towing operation from Belfast to Strangford went well with the Subhub handling well under tow as expected from the analysis- this demonstrates that the device can be installed using low cost support vessels. We are very pleased to be providing support to this exciting technology”.

MTS Taktow proved itself to be the ideal towing vessel with a bollard pull of 18t and at reasonable cost despite being mobilised from Brixham.

Belfast Harbour Pilots requested that another vessel of equivalent bollard pull was used in combination with Taktow within the confines of Belfast Harbour. QED Naval selected Ferran’s Farset with a 14t bollard pull. Ferran’s had been helping QED Naval with the towing setup and specification over the last few months so this was an easy decision.

The 50 nautical mile passage was carried out at an average towing speed of 3 to 4 knots and took just over 11 hours. The successful completion of the passage validates the claims made by QED Naval about Subhub in terms of high operational availability and hence high deployment rates and reliable maintenance schedules for tidal projects underlining the commercial benefits and reduced cost of ownership.

Arrival in Strangford Lough

Subhub arrived in Strangford Lough around 0930 on the Wednesday 16th January. The pilot from Cuan Marine joined the Taktow to guide them in over the treacherous Strangford Bar and through the Narrows on the flood tide at 1400.

The tow moved quickly through the Narrows at 4.5knots passing the iconic MCT tidal turbine now partially decommissioned. It was reputed to have cost £5m+ to install and something similar to remove. This encapsulates the driving principal of Subhub tidal platform given that it cost just over £100,000 to deploy including load out, launch, planning consents (MCA, MWS, BHC), launch, towing, moorings  and insurance. By anyone’s standard this is a transformational per unit cost reduction.

Passing the iconic MCT turbine in Strangford Narrows.
Subhub’s arrival at the holding mooring in Castle Ward Bay.
The beuatiful backdrop of Audley’s Castle better known as Winterfell Castle from Game of Thrones.

It is a pleasure to present the short video below of the deployment. If you have any questions or queries please contact QED naval directly.

Subhub Gets the Go Ahead from MCA

Immediately after the launch of Subhub in mid January, the QED Naval team succeeded in another major achievement which was the approval and certification of the Subhub to conduct towing operations in UK waters from the Marine Coastguard Agency (MCA).

The final certification was provided by Captain Danny Hawkins from the MCA Bangor, Northern Ireland. This was the culmination of many months work by the QED Naval team and the Marine Warranty Surveyors (MWS) used, Prolines based in Waterford, Ireland.

The certification from both MCA and MWS for the load line exemption and sailing condition survey was sent immediately to Belfast Harbour Commission and our insurance company and this was the final part of the authorisation for towing out of Belfast Harbour.

Launching Kraken into the Deep

Lift of Subhub

Subhub was lifted into the water on Monday 14th of January. The lift was managed and supported by Doyle Shipping Group who conducted all stevedoring operations and provided boat support. They contracted Kavanagh Cranes to perform a skilful dual lift using a 350t and 500t cranes. The weight on the hook was 146t which is just over 1% more than our estimated total hull weight of 144t and provided immediate confidence in the stability analysis completely by QED Naval.

Dual lift of Subhub into the water using 350t and 500t crane.
Barge used to support the Subsea Manifold (remote control connection to Subhub).

The barge used to support the Subsea Manifold was provided by Cuan Marine. The barge also supported the umbilicals used to provide the remote control of the Subhub platform used in this unique method of installing and recovering tidal turbines from the seabed. Finally the barge provided the tow operators with easy access to the emergency tow line and anchor.

The clever bit about Subhub is it’s fundamentally stable in the dive condition when submerged and the descent can be controlled using trim tanks easily. It is responds quickly to subtle changes in the ballast system so it can be installed safely or recovered in minutes over a wide range of tidal and wave conditions.

Subhub moored at the D1 quayside showing her waterline and draft marks.

The Subhub’s draft was measured at 3.8m when it was launched without the cross beam and turbines fitted. This is a little lower than expected but indicates that the stability analysis is conservative. The platform is very stable in this condition and with the guardrails fitted shows how safe access to the top deck allows marine operations to be performed whilst at sea.

There is full access to the tidal turbines above the waterline whilst in the transit or maintenance condition along with the PTO, electrical transmission equipment and connectors from the top deck.

Integration of Cross Beam and Tidal Turbines

The cross beam including the central turbine was fitted to the Subhub whilst afloat to minimise the overall weight of the lift. These essential parts of the payload were fitted in under 30 minutes using locating pins to provide the exact position to fit the cross beam to the foundation structure with the bolts.

The outboard tidal turbines were fitted in under 15 minutes and provides a useful check of the Subhub’s stability again by performing an inclining experiment which showed the draft levels on the port and starboard sides.

All these stages of the project validate the business model for customers where:

All the complex integration tasks, commissioning and testing are all done on the quayside or moored alongside as opposed to doing them at sea which raises major logistical and health and safety issues. This helps Subhub dramatically reduce costs of integration.

Tidal turbine being fitted to the starboard side of the cross beam support structure.

Validation of Stability

The final draft mark of the Subhub with all the systems fitted came to just under 4.0m draft. The trim of the vessel was completely level and there was no list. This was pretty remarkable since there are significant differences in the structure between the port and the starboard sides. The port side includes all the Power Take-Off and transmission equipment and additional structure to secure it in position. This all needs to be counter balanced with ballast on the starboard side. Therefore the results of the waterline checks shows  stability assessment was performed to a high standard by the QED Naval design team.

 

Subhub Moves to Shore Frontage

Subhub tidal energy platform was moved from Titanic Properties, Kingsworks car park on the Queen Island to Belfast Harbour’s D1 Area in readiness for deployment to Strangford Lough early in the New Year. The D1 Area is part of Belfast Harbour’s estate and was formally leased by Orsted to deploy the wind turbines to West of Duddon Sands project a joint venture project between Orsted (formally Dong) and  ScottishPower Renewables costing £1.6 billion.

Subhub set down at the D1 Area of Belfast Harbour in readiness for launch in the New Year.

QED Naval’ s team have worked professionally and tirelessly to complete this logistical process working with many commercial partners to achieve this major milestone. Significant technical and commercial issues have been overcome to achieve this milestone which has caused significant delays in the project but good things come to those who wait or persist.

That being said we need to thank the key players who helped us achieve the move to D1 milestone, namely:

  • Belfast Harbour Commission – Provided access to D1 Area authorising the route to quayside along with bridge assessments and civil engineering works.
  • Belfast Harbour Police – Have been long term supporters of the Subhub project completing patrols on a daily basis of the Kingsworks site. They also provide a police escort ahead and behind the route on the day of the move ensuring traffic safety.
  • Mar Train Heavy Haulage – who completed the move of the Subhub to the D1 Area. Their professionalism and performance on the night of the move amazed onlookers including ourselves.
  • HBS – Completed the plans (RAMS) for all the civil engineering works to be carried out along the route. They quickly and efficiently cleared the route prior to
  • AECOM – Completed survey, assessment and report of the bridge on Airport Road West which was on the route to the D1 Area.
  • Doyle Shipping Group – Supported the transfer of Subhub to the D1 Area in terms of weighing the Subhub, lifting plans and stevedoring, essential for the set down position on the quayside.
  • Titanic Properties – who have support QED Naval of the past 12 months providing a suitable lay down area on the Queens Island for them to complete the commissioning and testing of all the main systems.
Subhub at the first pinch point at Titanic Hotel on Queens Road.
Titanic Museum and the back of the Titanic Hotel.
Subhub set down at the D1 Area looking back towards Belfast with the Subsea Manifold and umbilicals used to control the ballasting process during installation and recovery.

The tidal energy sector is showing signs of growth within the UK for the industrial and tech sectors, led by Simec AtlantisOrbital and Andritz Hydro Hammerfest, who are leading developments on the back of good ROC support. However, since this support mechanism was dropped in April 2017, we find the development of the tidal sector is being lost to other countries including France, Canada and inevitably Asia.

We find that persistence is a key word in our business plan to get the message across to industrialists and corporates who have shown interest in the blue or sustainable economy recognising the longer term benefits of these high growth,  ethical investments for everyone’s future.

QED Naval developed the Subhub tidal platform to address the issue of high energy costs caused by the use of high value marine platforms such as DP2 vessels and jack-ups to install and recover the tidal turbines. QED Naval have developed a unique method of installing and recovering tidal turbines using their platforms unique submerged stability characteristics. This fully integrated platform which encapsulates everything required to operate seabed mounted tidal turbines, invisibly, and offers the industry reliable deployment over a wide range of weather conditions maintaining >80% operational availability over onsite wind, wave and tidal conditions.

Importantly, Subhub offers the opportunity to increase the site capacity or yield from the site by >40% transforming the commercial viability of any project.

In a recent feasibility assessment, QED Naval demonstrated, using actual site measurements at 6 different locations, how their project would be deployed along with the commercially measures to demonstrate the viability of the project. A clear conclusion of this work was, deploying a utility scale Subhub solution would enable the client to compete with offshore wind in the next CFD round in terms of LCOE, capacity and timescales for the project.

Moving the Subhub to the quayside in readiness for the launch of the Community Subhub Demonstrator is the first step in validating the claims of high yield and ease of installation and recovery.

 

Subhub Appendages Arrive Ready for Commissioning and Testing

The recent arrival of the Subhub’s appendages brings the build phase of this fully integrated tidal platform to a conclusion. QED will soon validate claims that Subhub provides a “tidal array in a day” along with easy and quick recovery for maintenance at the surface or in sheltered water.

The Subhub is a universal foundation platform and deployment / recovery method suitable for any type of turbine. It can be modified to capture the benefits of both Horizontal Axis Turbines (HATs) and/or Vertical Axis Turbines (VATs). The platform’s ballasting methods can work equally well with wave turbines as well.

The principle benefit of the Subhub is its ability to install a fully integrated, gravity based structure to the seabed including turbines, PTO equipment, ballast. It does this in a single and quick offshore operation using small support vessels which are commonly available making it a very cost effective solution.

However, Subhub also provides large performance advantages by steering the turbulent flows into the turbines enabling them to perform as expected in rated flow conditions significantly increasing site capacity factors and energy yield.

Subhub with all her appendages including Cross Beam to support the tidal turbines and the Subsea Manifold in the background to control the Subhub remotely from small support vessel or barge.

Measurements being taken on the Cross Beam for the fairing structure to be added with the tidal turbines and rotor blades lined up for assembly onto the Cross Beam post launch.
Subsea manifold with the port and starboard umbilicals offered up ready to connect all the pneumatic, hydraulic, data and power cables.

Full Stream Ahead To Tidal Turbine Assessments

QED are delighted to announce the appointment of Dr. Corey Badger. Her role maintains the sophisticated CFD numerical capabilities employed as part of the Subhub tidal platform design process. This uses High Performance Computing (HPC) capabilities which clusters all the high end workstations together to provide 32 core processor power with shared memory of 256GB enabling massive numerical models to run quickly providing tangible results on turbine performance within weeks rather than months. These capabilities are part of the companies ANSYS Fluent CFD package which offer state of the art modelling methods.

QED offers these capabilities and services to other companies working in the sector including turbine and project developers. This includes the performance characterisation of tidal turbines both with and without the Subhub tidal platform to assess the impact of the structure on their performance.

More recently the company has been working with Queens University Belfast (QUB) to assess the impact of Subhub on turbulence within the TTT3 project. This involves taking ‘as measured’ ADCP measurements and determine the turbulence content in it and applying turbulence factors to a numerical model of a rotating turbine in steady state condition that provides accurate general loading and performance data (Ct, Cq, Cp). The next stage is to run these models in a transient solution providing unsteady loading results of the turbine and Subhub.

CFD numerical model of the TTT3 turbines including ‘as measured’ turbulence and flow conditions used to predict the steady state performance characteristics and unsteady loading conditions.

There have been some interesting results to date and this work will be a large part of Corey’s role to validate the claims that Subhub has major performance and unsteady loading benefits on tidal turbines. Further claims of reducing the effect of tidal shear on seabed mounted devices and lessening the issue of turbulence and cross flows on the turbine blades by steering the flow into the turbines like stators of a pump jet.

Corey has also taken on the development of the company’s Tidal and Wave Energy Evaluation Tools (TWEET).  The main module of TWEET takes as measured or theoretical tidal harmonic models along with CFD/BEM performance data of the turbines and projects the energy generated from the inlet condition over a period of a year or the life of the project. Monte Carlo simulations can then be run from within TWEET to determine the economic viability of the project.

Monte Carlo simulations for the cost of the mass including fabricated mass and ballast mass.

The company has also started building its own GIS mapping tool to store and maintain site data including bathymetry, flow rates, positions of moorings, pictures and videos of seabed conditions and mammal, bird and fauna sightings for EIA studies.

Output from QEDs GIS mapping tool showing the position of the selected Subhub test sites at the QUB test centre along with flow data and bathymetry.

Corey brings new capabilities to the company having completed her Ph.D in multiphase flows using OpenFOAM, the open source CFD package. She has used the Edinburgh Parallel Processing Centre (EPCC) super computer to complete her Ph.D and now QED Naval have implemented Linux on a dedicated compute server to run OpenFOAM  capable of completing very large numerical calculations in excess of 10 million cells. Transferring these models over to the EPCC will provide fully validated results within days rather than weeks.

Subhub Project Fully Funded for the Sea Trials

QED Naval has successfully completed the final round of funding to complete the sea trials of their Subhub tidal turbine foundation platform. The funds have been raised through the existing shareholding with 75% raised through Kelvin Capital and the remaining through Scottish Investment Bank (SIB).

The funds will be used for ballasting trials to demonstrate how quickly and easily Subhub can be installed and recovered in real sea conditions (in waves and tide). The trials will also demonstrate the significant increase in energy generated by mounting the turbines on the Subhub platform (up to a 40% increase in power output) thereby increasing capacity factors and making some sites commercially viable. QED will then assess the performance impact of Subhub on tidal turbines in accordance with the IEC standards.

QED Naval are now recruiting 4 new positions building its team to support the next stage of trials and the ongoing technical development of the Subhub leading to the companies first commercial deployments. See the Team/Join Us link for further information. In short, the company is looking for:

  • Electrical & Instrumentation Control Engineer
  • Naval Architect
  • Fluid Loading CFD Engineer
  • Structures Design Engineer

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. Specifically, this collaboration has been part of the Tidal Turbine Testing project (TTT), which is used to determine the impact of turbulence on the prediction of tidal turbine performance. In summary, flow  measurements have been recorded using ADCP systems to try and understand the behavior of the turbines in turbulent conditions. These measurements have then been used by QED Naval to predict the performance of a hypothetical turbine and then determine the impact of Subhub on the performance with impressive results.

Streamlines through the semi-duct of the Subhub and sliding mesh turbine.

As a result of this collaboration QED Naval have decided to test the Subhub in Strangford Lough at the QUB tidal test site, leased from the Crown Estate.

Also, as part of the ongoing support, QED Naval are sponsoring 2 industrial Ph.Ds, one on turbulence modelling and the other on remote sensing mapping of resources as part of their involvement with The Bryden Centre supported by the EU’s INTERREG VA Programme. There are still vacancies for these posts so please follow the link for contact details if this is of interest to you. These studentships are not exclusive to Northern Ireland or Ireland but also includes the University of the Highlands and Islands so it has broad appeal.

Marine renewable engineering and design consultants