B5 - Design of reliable cabling systems

Cabling system can contribute to the total cost of the ORE system and can be a single point of failure. Therefore, a more cost effective cabling design will improve confidence in project financial projections. Existing cabling designs are generally inherited from the onshore/offshore wind farms or the offshore oil and gas sectors, which may not be effective for the floating ORE farms. More reliable cabling designs are needed for ORE systems by considering the cable damage hazards such as the exposure or suspensions caused by seabed variations, failures under extreme environmental loads. Detecting sensors are needed to monitor the electrical performance and physical condition of the cabling in a marine environment to reduce the O&M cost. Better cabling designs are needed to reduce the potential environmental impacts associated with thermal radiation and electromagnetic fields, etc.

Better understanding is needed of the cable mechanics, hydrodynamics, fluid-structure interaction and interaction with a moveable sea bed, thermal and electrical effects; revisit fundamentals of exposure and support to unlock more cost-effective designs.

Impact on CAPEX as more reliable cabling will be designed and therefore the design can be less conservative. Impact on OPEX as the cabling damage hazards will be fixed and detecting system will be applied, leading to reduction of the O&M cost.

Active and Recent Research Projects

Current Research:

• Offshore Renewable energy Cable Health using Integrated Distributed Sensor Systems
• HOME-Offshore: Holistic Operation and Maintenance for Energy from Offshore Wind Farms
• Offshore Wind Innovation Hub Roadmap - Electrical Infrastructure innovation priorities
• FLOTANT (Innovative, low cost, low weight and safe floating wind technology optimized for deep water wind sites): The main objective of FLOTANT is the development of innovative solutions to improve the robustness and cost-efficiency of 10+MW wind turbine generators in deep waters (100-600m). This goal will be achieved through the design and test of specific components, as well as the assessment and optimisation of the construction, installation, operation and decommissioning techniques, in line with state-of-the-art practices and environmental constraints

Previous research projects:

• A review of potential impacts of submarine power cables on the marine environment: Knowledge gaps, recommendations and future directions: Submarine power cables (SPC) have been in use since the mid-19th century, but environmental concerns about them are much more recent. With the development of marine renewable energy technologies, it is vital to understand their potential impacts. The commissioning of SPC may temporarily or permanently impact the marine environment through habitat damage or loss, noise, chemical pollution, heat and electromagnetic field emissions, risk of entanglement, the introduction of artificial substrates, and the creation of reserve effects. While growing numbers of scientific publications focus on impacts of the marine energy harnessing devices, data on impacts of associated power connections such as SPC are scarce and knowledge gaps persist. The present study (1) examines the different categories of potential ecological effects of SPC during installation, operation and decommissioning phases and hierarchizes these types of interactions according to their ecological relevance and existing scientific knowledge, (2) identifies the main knowledge gaps and needs for research, and (3) sets recommendations for better monitoring and mitigation of the most significant impacts. Overall, ecological impacts associated with SPC can be considered weak or moderate, although many uncertainties remain, particularly concerning electromagnetic effects.