Marine renewables power distribution hub

Renewable wave, current, tidal and floating wind devices that generate electricity float on the surface or subsurface and are anchored to the seabed. Connecting these devices to the national grid is challenging and hazardous, as electrical connections require to be made at sea to a floating platform. Umbilicalis are typically either exported from the shore directly to the floating platform or deployed to a network of generating devices. Recognised deficiencies in effective submerged interconnection of multiple devices in a single array was a driving force for the launch of this project. Prior to this project Hydro Group had developed the Hydro Group Renewable Connector (HRC), a 3-phase, 24 kV dry mate connector which was an evolution of our existing 11KV dry mate connector, designed to be part of a subsurface wiring system for renewable energy power generation units. The connector allowed wave and tidal energy converters to be deployed and recovered without disturbing the fixed wiring installation connecting them to the shore. At the commencement of this current project, there was a desire in the renewable energy industry to incorporate various connection points into the wiring system, enabling several devices in the field to be deployed from a single cable. However, technology was limited as suitable sealing and electrical isolation systems did not knowingly exist that would be appropriate for subsurface use. Extensive component prototyping would be required to adapt existing onshore surface designs to suit safety requirements and operating conditions offshore. Development of a cost effective yet robust multi-point subsea Power, Distribution Hub (HUB) suitable for the interconnection of heavy armoured seabed and dynamic umbilicals consisting of 3 MV power cores, low voltage cores and fibre optic components, with multiple renewable energy power generation units. The ability to utilise surface technologies and components wherever possible whilst maintaining relatively simple deployment, long term service life and minimised service intervention. To achieve this aim, the company was required to initiate research into the development of sophisticated filtering of partial discharge, and commenced investigations relating to suppressing interference using filtering screening. Methodology. Prototype components were developed and tested for durability, electrical connectivity and operational multi-level sealing in this harsh underwater environment As a result of this project, Hydro Group successfully developed, built and tested a suitable design for the multi-point connector and in August 2015 deployed the first unit on the SEMREV Renewable Energy Test Facility off the West Coast of France. This has led to the evolutionary design and development of other submerged HUBs and associated distribution equipment Through innovative thinking and design approach it was possible to package surface rated componentry into a sub-surface pressure rated HUB which was required to meet environmental, operational and budgetary requirements of the Offshore Renewables Market.