Detailed Design of the OE Buoy Duct Device for Wave Energy Conversion
Name of Applicant: Ocean Energy Ltd.
Grant Award: €131,157
Category: Shared Cost R&D
Completion Date: November 2004
Introduction
Ireland is located at the centre of one of the most favourable climates for ocean wave energy in the world. The medium term practical resource has been identified by the Marine Institute as around 800MW installed capacity. Currently, there are no commercially available wave energy converters which could be used to exploit this resource. While a number of countries are actively promoting their development, it is clear that there remains a large commercial opportunity open to a successful device developer.
The Ocean Energy Buoy (OEBuoy) is referred to as a floating oscillating water column (OWC) wave energy conversion device. This device uses wave energy to compress air in a plenum chamber and pumping it through an air turbine system (see attached figure). This isolates the power conversion system from the seawater and also provides a high speed air flow to the turbine.
The OEBuoy device is a floating system with the mouth of the OWC facing away from the wave direction. This results in high energy efficiencies at the operating point because of the motions of the float system relative to the waves. Interestingly however, the efficiencies reduce as the wave power levels increase which limits the output in extreme waves. The mooring forces in extreme waves are also reduced by the motions of the system. The system has a compact shape and is amenable to conventional shipbuilding techniques. These attributes contribute to the view that this device has the potential to be a commercially viable wave energy converter.
Ocean Energy Ltd. are working towards the construction of a 1MW Pilot Plant to be deployed and tested off the Irish Coastline. Successful operation of the Pilot Plant will allow Ocean Energy Ltd. to proceed to the commercialisation of these devices. The particular objective of this study is to finalise the preliminary engineering and costings so that the project may proceed, with low risk, to the next phase which is the construction of the Pilot Plant.
Overall project management is undertaken by Ocean Energy Ltd. and technical coordination is provided by the Hydraulics and Maritime Research Centre (HMRC), Cork. Activity under this project is grouped into the following work packages with appropriate contractors responsible for the output:
- Model Testing – HMRC (Cork)
- Air Turbine Design – IST and Ztec Ltd., (Portugal)
- Electrical Systems – CDGA and MES Ltd. (Cork)
- Mooring Systems – Marine Computation Services Intl. (Galway)
- Test Site – Ocean Energy and HMRC
- Hull Engineering and System Integration – TRITEC Ltd. Naval Architects (Glasgow)
Successful completion of this project will provide a preliminary design for the Pilot Plant and allow the costing to be undertaken with high degree of confidence. The risks of proceeding to the next Phase, which involves the construction of the Pilot Plant and relatively high investment, will be greatly reduced.
Current Status
The 1:15 scale model has been constructed and will be tested in Nantes in September. Contracts have been completed with the Portuguese Partners and preliminary specifications for the power take-off system have been received. Contracts have been completed and preliminary work has been completed. A draft final report has been received from MCS International for the mooring design. Site identification is proceeding within HMRC and discussions have been initiated with ESBI regarding the permissions and electrical interfacing. Preliminary hull designs have been received and OE Ltd. have had discussions with potential shipyards in relation to the costs.
For further information contact:
John McCarthy
Ocean Energy Ltd.
3 Casement Square
Cobh
Co. Cork
e-mail: oceanenergy@dol.ie
