The global transition to a sustainable energy mix requires the development of offshore wind farms. Connecting the electricity supply from offshore wind farms to the electricity grid on land demands reliable transmission from offshore to onshore through subsea cables. That is currently a challenge.
At present, failing subsea power cables are one of the main risks affecting offshore wind farm development and operations. These failures account for approximately 80% of insurance claims in the offshore wind industry. Their impact is so large because cable failures can shut down an entire section or even an entire wind farm. Additionally, cable inspections and repairs are expensive maritime operations. Repairs on cables can easily be delayed for a few weeks or months because of the weather or limited vessel availability, severely impacting revenue and reducing the technical lifetime of a subsea cable. Reducing the risk of subsea-cable failure will make the offshore energy grid more reliable and give us more control over the costs of the offshore cables throughout their lifetime.
A wide range of industry partners
The project was initiated by DNV-GL, TNO (ECN), BREM, VanDerHoekPhotonics and Deltares in collaboration with 30+ industry partners ranging from international suppliers to system integrators, end users and regulators. Due to the wide range of partners, improvements will be made in the areas of the design, installation, operations and maintenance of subsea cables. The consortium will create guidelines for transparent, industry-supported practice focusing on the main aspects of subsea cable systems and their failures.
Improvements for all phases of the lifetime of a subsea cable
The work will begin with a thorough analysis of the main causes of cable failures. On that basis, improvements can be made in the areas of the design, installation, operations and maintenance of subsea cables. Another important topic covered by the study is the development of lifetime monitoring techniques. ‘By continuously monitoring the cables from installation through to operation using optical fibres, we can establish a picture of why cables fail and develop an early warning system’, explains Jan-Joost Schouten, an offshore expert at Deltares. In addition, the project partners will improve the predictions of morphological features such as sand waves around subsea cables and develop a decision support tool to quantify the achieved cost reductions for offshore wind energy.
Applicable to existing and future wind farms
partners in this project aim to cut the levelised cost of electricity (LCoE), insurance costs and the CO2 footprint of the offshore industry. The project will take two and a half years and it is being supported by the Dutch Ministry of Economic Affairs and Climate Policy through the Netherlands Enterprise Agency (RVO).