An offshore wind farm only earns its keep when the electricity it generates reaches land. Between the turbines and the shore sit subsea cables, and those cables run through some of the busiest and most exposed water there is. Offshore wind cable monitoring is the work of keeping vessels away from them, so the power keeps flowing and the people working out there stay safe.
UltramapGlobal has protected subsea cables since 2009, and renewables is one of the five sectors we watch every day. This is how monitoring works for offshore wind, and why it belongs in the plan from the start rather than after the first scare.
What is at risk around an offshore wind cable
A wind farm is several assets at once: the subsea electricity cables, the turbines they feed, and in some cases wave and tide generators. UltramapGlobal works to prevent damage across all of it, so that supply stays continuous.
The threat is rarely dramatic. Most damage comes from ordinary vessels doing ordinary things in the wrong place, such as an anchor dropped over a cable or a fishing vessel working too close. Sometimes a ship simply strays off course. The cable does not announce that it has been hit. The first sign is often a fault, and by then the repair bill and the lost generation are already running. Watching the traffic is how that gets caught before contact.
How UltramapGlobal monitors offshore wind cables
UltramapGlobal is always on. Around a wind farm’s cables we set protection zones and police them for compliance, watching the vessel traffic around them without a break. AssetMonitor® reads the AIS data that vessels broadcast about their position and movement, drawing it from several sources at once and handling well over 100 million live AIS messages worldwide every single day.
Where it helps, we advise a layered defence: a 1,000 metre early-warning perimeter with a 500 metre action-required perimeter inside it. The outer ring is where a wind farm gets its protection. When a vessel crosses it, an alarm reaches the monitoring team, an analyst assesses whether it is a genuine risk, and where it is, calls the vessel and asks it to alter course. The aim is to settle it there, in the outer ring, before anything reaches the cable. Trained analysts sit behind the software, on watch 24 hours a day and 365 days a year.
The commercial case for monitoring
There is a commercial reason offshore wind operators put monitoring in place, beyond protecting the asset. A tailored approach to watching a cable plays to what UltramapGlobal calls its assurance not insurance credentials, and it almost always brings a significant reduction in the insurance premiums the operator pays.
The logic is straightforward. An insurer pricing the risk on an export cable is pricing the chance of a strike and the cost of the repair. A cable that is actively watched, with vessels warned off before they reach it, is a lower risk to underwrite. The goal on almost every UltramapGlobal assignment is to reduce cable strikes towards zero, and a lower strike rate is exactly what an insurer rewards. Monitoring is one of the few asset protection measures that can pay for part of itself through the premium.
Why monitoring belongs in the plan early
Every new wind farm adds export cables, and each one is a route that has to be protected for its whole working life. Bringing monitoring in from the start, rather than after an incident, means the baseline of normal vessel behaviour on that route is being built from day one. The live picture also draws on an archive gathered continuously since 2009, covering cable strikes, shipping routes, fishing patterns and vessel behaviour. A team that already knows what normal looks like on a route spots the abnormal sooner.
If you are responsible for the cables on an offshore wind project and want to know they are being watched, UltramapGlobal can be reached on +44 (0)191 233 6351 or at info@ultramapglobal.com. For the wider picture, see our guide to how subsea cables are protected.
Frequently asked questions
What is offshore wind cable monitoring?
It is the continuous watching of the subsea cables that carry power from an offshore wind farm to shore, to keep vessels from damaging them. UltramapGlobal monitors the electricity cables, the turbines and, where present, wave and tide generators, using AIS vessel tracking and trained analysts, 24 hours a day, 365 days a year.
How are offshore wind export cables protected?
By defining and policing protection zones around the cable, then monitoring vessel traffic constantly with AIS data. A layered defence, such as a 1,000 metre early-warning perimeter and a 500 metre action-required perimeter, gives the team time to warn a vessel off before contact.
Does monitoring reduce insurance premiums?
UltramapGlobal states that its tailored approach almost always brings a significant reduction in the insurance premiums the asset owner pays, because an actively watched cable is a lower risk for an insurer to underwrite.
When should offshore wind cable monitoring start?
As early as possible. Monitoring from the start of a cable’s life builds the record of normal vessel behaviour on that route straightaway, which helps the team recognise a developing risk sooner.
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