As Marine Current Turbines (MCTs) are very large, fixed-structures, which are submerged underwater, they present a collision risk to other vessels that may operate in surrounding waters. For example, we envisage the 1st generation of 1MW MCT units with rotor diameters of around 16m, to be installed in depths up to 50m in groups (or farms) of 20 to 30 units. Such schemes could present a major hazard to other vessels and risk damage to both vessel and turbine. The navigational risk must therefore be estimated, by calculating the current volume of traffic in Scottish waters. Sites of low traffic volume are obviously preferable. Additional navigational aides such as lights and buoyage mounted on the top of the monopile structure would help reduce the risk of collision.
Figure : Traffic volume per day (figure taken from 1)
Using the Shipping Navigational Risk Assessment for Scottish Waters (completed by Anatec for Scotlandís Renewable Resource Volume 1: Analysis), each site was a ranked from 1 to 6 to indicate the volume of traffic and hence level of risk. For example, the area of Flotta in the Pentland Firth scored 6 indicating high shipping density of >5 vessels per day, whilst the Kyle of Rhea scored 1 signifying a density of 0.05 vessels per day (or between 0 and 18 vessels per year). Sites with a lower ranking were preferred when selecting the sites.
back to top