The ‘Offshore Transmission Network Review’ (OTNR), investigated the existing offshore transmission
regime to address the barriers it presents to further significant deployment of offshore wind, with a
view to achieving net zero ambitions. With increasingly ambitious targets for offshore wind,
constructing individual point to point connections for each offshore wind farm may not provide the
most efficient approach and could become a major barrier to delivery given the considerable
environmental and local impacts, particularly from the associated onshore infrastructure required to
connect to the national transmission network. The electrical infrastructure and grid connections
throughout the UK have been reviewed and identified the limitations of the existing grid network. As
we deploy more offshore renewable energy (ORE), a new transmission strategy is required to ensure
a more coordinated approach for the future as an enabler to meet the ‘Prime Minister’s – Ten Point
Plan for a Green Industrial Revolution’ to de-carbonisation3
.
As part of the electrical infrastructure analysis, focus will relate to what would be new and require
development in the future to meet the ambitions of 50 GW by 2030, for OSW (including 5 GW for
FOW). Therefore, integrating this level of OSW into our energy mix, requires careful consideration to
variability and intermittency, and makes the aim to deliver 95% low carbon electricity by 2030, using
a combination of electricity and hydrogen even more important. Establishing a green hydrogen
economy that would supply circa 130 Tera-Watt hour (TWh) per annum, would require circa 40 GigaWatt (GW) of OSW energy to balance the equation.
This report focuses on the electrical challenges, particularly the cable connection interfaces of wet
mate cables and FOW turbine interface options as part of a wider analysis to support the OTNR
strategy. The report includes a cost benefit analysis, and considers the practicalities of wet mate vs dry
mate connectors, for example, whilst integrating embodied carbon considerations. Also considered
are the performance features of wet mate connections from previous and new research conducted by
ORE Catapult, to address amongst other things, voltage, current, frequency, and power limitations to
electrical infrastructure solutions relevant to future FOW installations.