Sabotage Increases Cost of Installing Subsea Cables

The is an English translation of the Opinion piece ''Sabotage maakt aanleg zeekabels duurder', that got published in the Dutch Newspaper NRC on 14 Januari, 2025.

Billions of euros in new investments in energy infrastructure are needed to make the energy transition in Europe a success. These investments include new solar and wind farms, battery and hydrogen storage, and kilometers-long electricity cables and pipelines.

A significant part of this infrastructure will be placed under the sea to transport electricity between countries. Examples include the 250-kilometer Lionlink cable between the Netherlands and the United Kingdom, and the 1,250-kilometer Baltic Sea Hydrogen Collector pipeline, which connects Sweden, Finland, Germany, and Poland. But with recent reports of sabotage attempts in both the North Sea and the Baltic Sea, the question arises whether Europe is making itself more vulnerable with these investments.

Offshore electric cabling on the docks at Barrow in Furness for the Walney Offshore wind farm, Cumbria, UK. Source

Interconnectors

On paper, these subsea cables and pipelines—also known as interconnectors—appear to be the perfect transport solution. We produce green hydrogen in places where it’s cheap to do so, such as sunny or windy areas, and then transport it to countries where there is demand for green energy.

These interconnectors are also essential for our future electricity grid. Since solar and wind energy production is variable, there will be more frequent moments in the future when we produce insufficient electricity. We can supplement these shortages by importing green electricity from countries where the sun is shining or the wind is blowing. Sometimes, this requires spanning large distances. The UK, for instance, is exploring the possibility of laying a 4,000-kilometer cable to Morocco, where the sun almost always shines.

A study by energy think tank Ember expects the capacity of these cables in Europe to double over the next ten to fifteen years. This doubling is a cause for concern due to the recent increase in sabotage attempts and the limited insight into the precise scope of the problem.

Currently, the risks of sabotage to subsea cables and pipelines, and their associated effects, are insufficiently considered in new infrastructure plans. This needs to change. There are three key steps we must take to better account for these risks in our decision-making.

First, it’s important to map out these risks more clearly. NATO, among others, is working on this through the recently established Maritime Centre for Security of Critical Undersea Infrastructure. Predicting future risks remains uncertain. Still, we must take these risks seriously and not ignore them. One way to do this is through so-called “war games”—running various scenarios with multiple stakeholders. This can help us be better prepared for future dangers.

Second, extra measures will be needed to reduce risks. Think of more patrols, checking suspicious vessels, reinforcing cables and pipelines, or installing seismic detection systems. These measures will further increase project costs, which are already estimated at three to seven million euros per kilometer. It is important that they are included in the plans.

Political Choice

Third, it’s essential to better understand the consequences of cable failures. If a cable fails, it does not always lead directly to an energy crisis. But if it takes a long time to get the cable operational again, it can cause rising energy prices in the European market. The consequences for the entire European energy market can be significant.

Finally, this is also a political decision. Is the risk of vulnerable energy infrastructure worth the investment, or are there alternative, more expensive solutions that are less vulnerable to sabotage, such as more battery and hydrogen storage? This decision must be made carefully. The energy transition in Europe is already a massive challenge, so we must ensure that every euro we invest is well thought out.