As nations accelerate the shift to low-carbon energy, subsea high-voltage direct current (HVDC) interconnectors have become critical arteries in our modern energy networks. They facilitate the efficient transfer of electricity between countries, supporting grid stability and flexibility.
But their strategic value is matched only by their vulnerability. The failure of a single HVDC link can destabilize an entire energy system, and the financial stakes are staggering. Deploying an HVDC subsea network requires a capital outlay that can approach £200 million. A single cable failure can lead to interruption and repair bills ranging from £30 million to £100 million.
With insurers increasing their scrutiny and often excluding risks like sabotage from coverage, comprehensive, proactive risk mitigation is not just prudent—its essential for survival.
Effective risk mitigation doesnt start on the installation vessel; it begins months or years earlier in the planning phase. Route engineering must account for both the immediate challenges of construction and the long-term operational threats an asset will face. Strong planning disciplines are proven to significantly lower failure rates.
This is the focus of specialist teams like TGS | 4C Offshore, which provides subsea cable consultancy across the full asset lifecycle, from concept to decommissioning. Their risk-based approach ensures that decisions made in early development remain coherent and defendable through design, manufacturing, commissioning, and operation.
The need for a higher industry standard is clear. A joint review by Lloyds and Codan revealed that more than 60% of total insurance claim values originated from in-situ failures during a projects early operational phase, chilling investor and insurer confidence.
Successful project delivery requires a deep understanding of the entire risk landscape. Engaging owners, developers, financiers, and insurers early with full transparency is key to creating an aligned project blueprint.
Risk planning must account for a vast range of technical, logistical, and environmental issues.
Mitigating these risks depends on timely and accurate data. Geophysical and geotechnical surveys are essential for route optimization, while burial and cutting trials determine if trenching is viable or if rerouting is required. Burial Assessment Studies (BAS) and other field surveys help inform these crucial strategies.
Where minimum burial depths cant be achieved, the project must justify alternative protection methods like rock dumps or mattresses. Coordinated design and procurement, with tight collaboration between suppliers and contractors, is vital for smooth execution.
The plan must also include robust contingency planning for poor burial conditions and stakeholder engagement with everyone from marine warranty surveyors to local fishing interests. Finally, a post-installation survey closes the loop, verifying burial depth and satisfying commitments to permitting authorities.
HVDC subsea interconnectors can and do operate reliably, but only when engineering, commercial, and regulatory considerations are integrated from day one. Overlooking any single element introduces the risk of failure, added costs, and timeline slippage.