Today, 13 August, the Electricity System Operator (ESO) announced After 2030: Celtic Seaits recommended design envisages the connection of up to 4.5 GW of floating offshore wind energy capacity for renewable energy, enough green electricity for over four million households.
The recommended design proposes connecting up to 3GW to two sites in South Wales and up to 1.5GW to the South West of England, with each of the three proposed offshore wind farms (also known as Project Development Areas or PDAs) having its own connection to the onshore electricity grid. The proposals include a high voltage direct current (HVDC) link to a potential new interconnection node in South Wales and two high voltage alternating current (HVAC) links to Carmarthenshire and North Devon.
A number of shortlisted designs were rigorously assessed against four design objectives – impact on local communities and the environment, cost to the consumer, deliverability and operability – allowing ESO to produce a recommended design that carefully balances these considerations. The recommendation has less environmental and community impact than others considered during the design process, and no new overhead power lines are planned to connect the offshore wind farm.
The proposals also take advantage of the currently wider transmission infrastructure compared to other options and, in the case of Carmarthenshire and North Devon, recommend regions with an already identified need for a substation or an already proposed substation (for example Llandyfaelog in Carmarthenshire). This alignment with other infrastructure requirements could lead to a more coordinated approach to the siting of new substations.
The proposals will enable the Crown Estate’s fifth round of leasing of floating offshore wind in the Celtic Sea, a nationally significant facility comprising 4.5GW of floating offshore wind connected directly to the transmission grid – one of the largest floating wind initiatives in the world.
Independent research states that Leasing Round 5 and the associated supply chain could create 5,300 permanent jobs and increase economic activity of up to £1.4 billion during the construction phase of the projects.
The Celtic Sea design differs from other network design exercises ESO has undertaken previously as developers have not yet submitted bids for the opportunity to develop the three seabed areas identified by The Crown Estate for this leasing round. This new approach to sequencing allows developers to submit a more informed bid based on the network recommendations, thereby reducing risk.
This also allows ESO to take a new approach to the connection queuing for this Round 5 capacity, effectively pre-fencing the 4.5 GW so that we can efficiently proceed with the connection contract process when the seabed leases are awarded by TCE.
ESO conducted this assessment as a follow-up to its Holistic Network Design (HND) publications. Path to 2030 And After 2030which set a course to enable the delivery of up to 86 GW of offshore wind energy by the 2030s and beyond.
The After 2030: Celtic Sea The design creates opportunities for the South Wales and South West regions to continue to play a key role in the UK’s green industrial revolution, with links to the region providing a catalyst for future coordination with green energy developments in these areas. ESO worked with a group of representatives from local councils in South Wales and the South West to discuss optioneering exercises and gather feedback to be considered as part of the design development.
Following the proposals, ESO will work with the Transmission System Owner (TO) – in England and Wales this is the National Grid Electricity Transmission (NGET) – to advance the relevant work for this Recommendation as it moves into the detailed network planning phase.
Julian Leslie, ESO’s Director of Strategic Energy Planning and Chief Engineer, said: “Offshore wind is critical to meeting the Government’s objective of generating clean electricity by 2030, maintaining energy security and achieving a carbon neutrality target by 2050. So it is a really positive development to see an offshore wind leasing round being launched for the first time with a high-level recommended network design already in place.
“We have embarked on a rigorous process, in consultation with a range of stakeholders, to design the network required to connect enough renewable energy to power four million homes. Our proposal has additional potential to act as a catalyst for coordination with future green energy developments in South Wales and South West England.
“We are committed to delivering a clean, secure and decarbonised electricity system as envisaged by the Government and devolved governments, through collaboration across all parts of the energy sector, Government, the regulator and within our communities across the UK.”
