Innovation at work: Cable Thermal Guard

Turning operational insight into competitive advantage

As offshore wind farms grow in size and ambition, the ability to transmit power efficiently is becoming just as critical as the wind turbines that generate it. Decades of operating experience across our global portfolio have given us a deep understanding of how offshore assets behave in real conditions.

Cable Thermal Guard (CTG) – a new approach to assigning power ratings to subsea cables – shows how we’re turning our understanding into innovation. By combining data, engineering insight, and digital tools, CTG enables smarter use of existing infrastructure, unlocking additional capacity and value without changing physical cable designs.

Conservative cable ratings limit performance and flexibility

Subsea cables are typically assigned fixed power ratings based on conservative design assumptions, many derived from onshore applications. While these approaches prioritise safety, they often fail to reflect actual offshore operating behaviour.

In offshore wind, this conservatism can constrain performance. Cable ratings may limit output during high-wind periods, drive curtailment during outages, or lead to more complex and costly designs in early project phases. For large wind farms, even small constraints can have a significant impact on revenue, schedules, and bid competitiveness.

The challenge is how to increase utilisation of subsea cables safely, without compromising reliability or asset integrity.

Risk-based cable management using real-world data

Cable Thermal Guard replaces static limits with a risk-based approach grounded in actual offshore performance. Using Ørsted’s historical and live cable data together with environmental and operational inputs such as load profiles, weather conditions, and seabed thermal properties, CTG predicts cable temperatures with high precision.

Rather than assuming constant maximum stress, the method models how heat builds and dissipates over time. This allows teams to understand not just whether a limit might be exceeded, but also how often, by how much, and with what consequence. In practice, it allows cables to safely carry more power for short periods when conditions allow, while remaining within clearly defined risk thresholds.

Importantly, CTG achieves this without altering physical cable specifications. It maximises the value of standard, off-the-shelf cables through better insight rather than additional hardware.

From binary limits to informed decisions

Traditionally, cable design decisions are either pass or fail. Cable Thermal Guard introduces nuance by quantifying the likelihood and impact of potential overloads, turning cable ratings into a managed operating envelope rather than a hard stop.

This enables engineering, generation, finance, and project leadership teams to evaluate trade-offs transparently, and supports faster decisions in early project phases, clearer justification of design choices, and greater confidence when operating closer to technical limits.

Delivering value across asset life cycle

Cable Thermal Guard is now being rolled out across Ørsted’s projects, with tangible benefits already realised.

During the project development phase, it has strengthened bids by enabling higher export capacity assumptions and leaner cable and substation concepts, reducing unnecessary conservatism while avoiding unacceptable risk. For assets already in operation, CTG has reduced curtailment during peak production and planned outages, allowing more power to be transmitted through existing cables when conditions permit.

At the portfolio level, it has helped us avoid delays, reduce the risk of redesign work, and establish a repeatable approach that works across regions and projects. The method also forms the foundation for digital-twin-based optimisation over full asset lifetimes.

Built to scale, hard to replicate

Cable Thermal Guard reflects Ørsted’s broader innovation model: close collaboration across our engineering, digital innovation, EPC, and generation teams, combined with unparalleled access to real-world offshore data.

By challenging industry assumptions and replacing conservative limits with quantified risk, CTG gives Ørsted a durable competitive edge. It enables us to deliver more renewable power, improve project economics, and unlock additional value from infrastructure already in the seabed, without compromising on safety or reliability.