Location

Approach

The first approach towards the selection of the best location for this ambitious project was to come up with a list of requirements to be accomplished. The UK waters has been selected as the location of the project for two main reasons:

Essential Requirements

The main requirement was to have sufficiently high wind and wave energy resources in the location selected. The minimum resource requirements were:

The challenge on this point was to find a place with enough wave energy resource to justify the installation of wave energy converters, without being so far from shore to become prohibitively expensive.

Wind Resource

Figure 1 illustrates the wind resource in the United Kingdom, as provided by The Crown Estate.

Figure 1. Wind Energy Resource [1]

Wave Resource

Figure 2 illustrates the wave resource in the United Kingdom.

Figure 2. Wave Energy Resource [2]

In addition to the data sources indicated above, the ORECCA GIS database was found to be extremely useful for assessing potential sites. Initially the area highlighted in red in the following figure was found to have adequate wind and wave resources.

Figure 3. Initial Location Selection (created using ArcGIS)

Depth

Another requirement of significant importance is that, because of the floating wind units need to have a water depth of more than 95 meters owing to their deep draft, it was necessary to find a region within the location selected to comply with this requirement. The maximum depth is restricted more by cost than by technical restrictions, as such the aim was to limit the depth to less than 120 m.

Figure 4. Depth [3]

Environmental Protected Areas

The main mitigation/prevention measure to avoid environmental and social impacts is to find the correct location of the project. Therefore, it was essential to locate this expansive project, in a location in which the environmental and social impacts would be minimised.

Figure 5. Environmental protected areas [4]

Onshore Connection

Selecting a place accommodating an onshore main grid substation was crucial, to support the main aim of the project of cost reduction. There is an onshore substation in Dounreay currently operated by SSE at 132 kV (soon to be upgraded to 275 kV). The export cable would be connected to this substation which transforms the voltage from 132 kV to 275 kV for transmission to the main grid.

Figure 6. Onshore Substation [5]

Seabed

It is necessary to have the appropriate seabed to anchor the mooring lines for both the wind turbines and the platform. Within the selected site there are a range of seabed conditions and, as such, it would be eminently feasible to use micro-siting to find suitable locations for each wind turbine and the platform (Figure 7).

Figure 7. Seabed [6]

Shipping Routes

Shipping traffic has been taken into consideration to determine the final location. Figure 8 demonstrates the shipping routes all over the UK.

Figure 8. Shipping routes [7]

Site Selection

Gathering all the information obtained from these requirements, the region in red, demonstrated in Figure 9, was selected to locate the project, as it achieved the optimum balance of the requirements and constraints.

Figure 9. Project Location (created using ArcGIS)

To summarise, the location selected has excellent wave (30-40 kW/m) and wind energy resources (9.6-11.3 m/s), it has a depth of more than 95 meters, avoids main shipping routes, environmental protected areas, has appropriate seabed conditions, and is close enough to a high capacity onshore grid connection point as possible (75 km).