Abstract
In order for tidal stream technology to develop into a viable and cost effective energy solution, the overall cost of tidal array installation, operations and maintenance must be driven down. The key issues which drive the cost are the time required to conduct operations and susceptibility to weather risk coupled with the expense of marine assets.
Current vessels have limited operational windows due to weather and tidal constraints, which result in considerable cumulative costs due to high charges for such vessels. The marine renewable industry is currently reliant on vessels of opportunity from the offshore oil and gas sector; which, while sufficient for single device demonstration deployments, are not viable for array installations. De-coupling the tidal sector from this market place offers the opportunity to reduce the volatility of vessel day rates.
This paper presents the concept design of an efficient and economic, fit for purpose installation vessel for tidal stream energy converters. The vessel has good dynamic positioning capabilities for operation in strong tidal currents thus broadening the operational window. The environmental impact of the vessel is reduced when compared to existing vessels. A key criterion throughout the design process is minimizing the cost of the vessel to tidal turbine site developers.