Export and inter-array cables are exposed to a hostile, high-risk environment during a wind farm’s operational life. Given that they comprise a hefty portion of an offshore wind farm’s capital expenditure costs, preventive maintenance for submarine conductors should be a priority for operators, according to the latest Offshore Operations and Maintenance report from Wind Energy Update.
Roughly 27% of an offshore wind farm’s capital expenditure is ploughed into cable, cable installation and grid connection. For a generic park size of 500MW, a capital investment of €72 million is expected to be spent on export cables, and €24 million on inter-array conductors. These costs are augmented by precautionary measures, say the report’s authors. An estimated €840,000 is required for J-tube seals, bend restrictors, stiffeners and cable mats, alone, simply to minimise premature deterioration and failure.
An up-to-date, exhaustive breakdown of submarine cable CAPEX, coupled with a holistic overview of offshore wind farm cable failure is merely a fraction of the offshore O&M topics covered in Wind Energy Update’s Offshore Operations and Maintenance information-packed report.
Mapping the failure landscape
A wide range of variables can affect the lifecycle and reliability of subsea cabling, with a significant impact on operational expenditure. Seabed conditions, wave action and tidal effects, coupled with ship transit and fishing activity take a heavy toll on the submarine conductors. As such, the level of exposure of conductors should be a critical design driver, stress the authors of the latest Wind Energy Update Offshore O&M report.
Fortunately for operators, many variables such as dragged anchor, plough tipping, water damage, j-tube damage and cable faults, among other things, are insurable. However, activities around the offshore wind park will likely lead to considerable seabed disruption, warns the report.
