Arklow Bank Wind Park – Onshore Infrastructure Assessment
The Arklow Bank Wind Park (ABWP) is located some 8-12 km offshore, to the east of Arklow town in County Wicklow off the east coast of Ireland. When completed, the wind park will have an export capacity of 520 megawatts which the developer estimates will power almost 450,000 homes annually and offset over half a million tonnes of carbon emissions each year. In 2003-2004, the first phase of the project was completed with the construction of seven wind turbines with a capacity of 25.2 megawatts.
Sure Partners Limited retained Sweco to prepare a site assessment report to establish a preliminary basis and shortlist of options for the onshore cable route and substation locations for Phase 2 of the project. Sweco’s appointment included an initial site assessment of a number of cable route options (220 kV underground cable) and sub-station locations for the onshore element of ABWP.
The land-based grid connection for an offshore wind energy project is a significant element of the entire project. The objective of the initial assessment was to identify feasible route options and sub-station locations following the identification of constraints within a defined study area. It was vital that the connection route options were adequately appraised to ensure that an optimum route and substation location could be chosen to de-risk the overall project.
Sweco’s assessment looked at varying types of connection designs as well as two technologies for the onshore substation – Air Insulated Switchgear (AIS) and Gas Insulated Switchgear (GIS).
Once a number of potential cable routes were identified, they were assessed against defined criteria, initially as a desk-based exercise. These included:
- Environmental constraints
- Planning constraints
- Ground conditions
- Key infrastructure crossings include roads, railways, watercourses and service crossings
- Access point and traffic considerations (sub-station locations)
- Grid considerations
- Construction on public roads versus private lands
- Overall constructability review
Once all of the above constraints were mapped, we examined the remaining lands to identify suitable land parcels for the varying substation options (and construction compounds) in addition to cable corridors from the defined landing points. From this analysis, we prepared a report ranking the various options and recommendations.
- Environmental and Engineering constraint study
- Route options and site selection