Seacore

Objectives of the Project The primary objective of the SEAFLOW project is to develop and demonstrate the world's first commercial scale, grid-connected marine current turbine. The axial flow, horizontal axis turbine, which is expected to have a rotor diameter of 15m will be mounted on a monopile set into a socket in the seabed in a water depth of 20 to 30m. The unit will have a rated power of about 300kW (depending on local site conditions) which will give essential experience for the introduction of slightly larger commercial systems at a later date. The top of the monopile is likely to be surface piercing (i.e. will remain above sea level). A central aim is to move towards developing engineering capabilities needed for delivering economically viable marine current turbine technology. Key technical requirements are to seek adequate reliability and durability combined with efficient performance, while keeping costs low. Technical Approach The main thrust of the work involves two key activity streams: firstly the conceptualisation, detail design and manufacture of the turbine system itself and secondly site selection, survey and preparation ( the site will be in UK coastal waters, and chosen to offer a peak current speed in the range 2 - 3m/s). Following from this there will be the installation and operational phase. The major components will be designed by the consortium partners. The system needs to be sufficiently robust to withstand the rigours of installation in a hostile sea environment. The installation process will be undertaken from a jack-up-platform which provides a stable base, even in adverse sea conditions. A socket will be drilled in the seabed to accommodate the mounting pile which will be manoeuvred using a crane and firmly grouted in position. The remaining components will be manipulated into position on the pile from the jack-up platform and close-quarter support vessels. Following installation and preliminary system testing the grid-connection will be established via an appropriate transformer, marine cable and land-line. There will then be a series of short daylight runs to establish the device is performing satisfactorily, prior to initiation of unattended service. Routine maintenance will be undertaken at regular periods; possible design enhancements / operational adjustment may also be required, depending on system reliability and performance. Expected Achievements The entire project will last 36 months. On the basis of the proposed rotor diameter and anticipated flow characteristics, the peak power output of the device is expected to be in the order of 300kW. The energy output of the device is expected to be of the order of 1000MWh/year. The project will also serve to address the following questions:- Confirmation of the proposed methodology for installing, maintaining and removing a submarine turbine of 15m in diameter without the need for costly manned underwater operations Assessment of techniques to mitigate detrimental performance due to marine growth Confirmation of the effectiveness of an innovative system for yawing such a turbine to face the current from either direction and to stop the system in an emergency Assessment of extreme loadings, dynamic problems (such as vibrations), cavitation effects on the rotor. It is expected that the project will lead directly to a second phase involving the development of a full-scale demonstration of a multi-megawatt cluster of turbines. This in turn could lead to commercial exploitation of the technology within a lead-time of about six to ten years.