Tidal array cost reduction: Testing a removable nacelle design for DeltaStream Technology

The tidal renewable energy sector is at a stage where it is going to expand with larger devices and arrays of devices. An estimation of nearly 4GW of installed capacity by 2020 is likely by 2020, enabling the sector to make a serious contribution to the energy requirement. Moving the sector forward from its current infancy still requires evelopment of fundamental aspects of the technology in order to provide greater cost efficiency. One particular area is to significantly reduce the cost of deployment and recovery for maintenance. Given the harsh environment in which the devices are deployed and the costs associated with the vessels, the speed of recovery is essential to reducing the life costs associated with the energy generated over a device lifetime.

Hence the urgent need to reduce the installation and maintenance costs of the DeltaStream system. The current project proposes an effective wet-mate nacelle removal system for cost-effective installation and recovery.

Cardiff University will assess the lifting dynamics involved in lowering the turbine from the surface of the sea onto the structure and evaluate the connection aspects of the novel design of the Deltastream. Integrated with physical testing by the project partners, the data will provide feedback to the industrial partner to assess any modifications needed to the proposed design

This Work Package focuses specifically on the modelling the dynamics of lowering the turbine from the surface of the sea into the wet-mate socket. Specifically Ansys software will be used for the modelling. The outputs of the workpackage will also provide feedback to the component testing and final device assembly undertaken as part of the overall project.

The collaboration between industry and academia will provide an effective partnership for the research and development of wet-mate system which will help drive down the cost of deployment and recovery of the turbine, hence the cost of the energy generated. The implementation of this design into the Deltastream device will provide a major advancement in the technology. The gravity mounted system already allows for reduced deployment costs, the ability to remove/replace a turbine within the short window of opportunity provided by the harsh environment will further drive down the cost of generating electricity. The speed of replacement will also ensure the security of supply (of electricity) when maintenance is required, which in turn will ensure the growth of this sector. The follow on is the development and security of the supply
chain; Ultimately job creation in the UK.

Key areas of impact of this work will be as follows:
Academia: Where data gathered in the project is free of commercial sensitivity, it will also be shared with the academic community for application to research activities related to other significant projects in the marine and maritime sectors. The research assistant will benefit from the direct contact with the industrial partners and active involvement with an industrial scale development. Attendance at a conference will allow for networking and discussions with leading experts in the marine energy research and development.

Device designers: The UK is the world leader in the area marine energy, specifically with the development and deployment of devices. The development of the technology described in this proposal will have a significant impact on the developer and accelerate the deployment of the first array of the Deltastream devices. As with most investors the risk and payback are vital, so a reduction in both the risk and the payback period will encourage independent investors, so also accelerating the deployment of arrays.
TEL will on successful development of the wet-mate system by the end of the project look to implement and integrate the design into their existing Deltastream. Hence the research and development will be rapidly utilised into an industrial application

Energy companies, Consultants and Policy makers: The reduction of the cost of electricity from a renewable energy source will allow for greater investment from the energy companies and help meet the reductions in emissions targets. The
development of the marine energy industry through best practice at low cost will help Policy makers and consultants inform the wider community at both national and international levels.