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  • Writer's pictureAlastair MacLeod

Celtic Sea Round 5 Opening

The leasing process for Round 5 is due to get underway later this month (February 2024) and will see three sites being auctioned with combined capacity of up to 4.5GW – enough to power more than 4 million homes.

Last week (12th Feb 2024) The Crown Estate announced that it had concluded its Habitats Regulations Assessment (HRA) across the Round 5 Celtic Sea has concluded that protected environmental sites will not be adversely affected by the Test and Demonstration projects, and the development opportunities that will be offered as part of Round 5. This information has been made available ahead of the start of the bidding cycles.

Pre-consent surveys are also being conducted by The Crown Estate, which includes geophysical surveys with 250m line spacing over Project Development Areas (PDA) 1, 2 & 3 (Figure 1). Subsurface data will comprise sub-bottom profiler (SBP), with penetration to 15m below seabed, and multi-channel ultra-high resolution seismic (UHRS) with penetration to 50m below seabed. However, data from these surveys will be ringfenced and provided only to successful bidders, whilst according to Graham Moates (Senior Marine Survey Manager) during the Q&A on Bidders Day in Swansea, The Crown Estate will issue a “Technical Note” later in 2024 once the summer geophysical campaigns and interpretations are complete.

Our assumption is that, until this technical note is released, participants within the Celtic Sea Round 5 bidding process will remain in the dark when it comes to understanding the potential subsurface risks, particularly soil thickness and bedrock depth/type.


The ScotWind Case Study: From E1 to Ossian

The Ossian offshore wind farm has the potential to become the world’s largest floating offshore wind farm with a capacity of 3.6GW… enough to be capable of powering almost 6 million Scottish homes annually (according to project website).

It is now 3 years since the completion of a joint project between RockWave and Atkins, for the consortium of SSE, Marubeni and CIP as part of their ScotWind application process for offshore wind leasing at the Ossian site, then known as E1.

The project explored whether additional information about the potential ground conditions at their site could be gained by reprocessing, repurposing and then interpreting historical O&G exploration seismic data. More information on this project can be found by reading our Repurposing landing page.

When the consortium looked to utilise the Repurposed O&G seismic data, the overall area of search was 3, (Ossian is now and our seismic data provided a coarse grid of regional coverage across the whole site.

PDA 1, 2 & 3 cover an area of approximately, will generate 4.5GW and RockWave Repurposing has a line density very similar to E1/Ossian. Clearly there is equal value to be gained by utilising Repurposed O&G seismic in the Celtic Sea Round 5.


Repurposing Value in Leasing Process

RockWave’s Repurposing has already been accessed by several developers interested in participating in the Round 5 bidding process for the delivery of floating wind projects in the Celtic Sea.

This bidding process is going to consist of four stages:

1. Pre-qualification questionnaire (PQQ)

Bidders’ technical experience, financial standing and legal compliance will be evaluated, with successful Bidders becoming pre-qualified to participate in ITT Stage 1. The PQQ will also provide a summary of the Key Legal Agreements to be entered into in connection with the Round 5 Developments.

2. Invitation to Tender Stage 1 (ITT Stage 1)

Bidders’ ability to deliver a Round 5 Development will be evaluated. The evaluation will focus on Bidders providing evidence of technical and HSE capability to successfully deliver a Round 5 Development in any one of the PDAs and their intentions regarding integration ports and plans to deliver social and environmental value during the term of the Legal Agreements. ITT Stage 1 will also establish the Maximum Level of Cash (MLOC) available that will be relevant to ITT Stage 2.

3. Invitation to Tender Stage 2 (ITT Stage 2)

An Auction which will award each respective PDA when there is no more than one Bidder who is willing to meet the Auction Price for each PDA in any given Auction Round. Bidders will need to sign a Preferred Bidder Letter to participate in this stage of the process.

4. Entry into Wind Farm Agreements for Lease

Each PDA will be governed by a separate Wind Farm AfL. Preferred Bidder Letters will not be entered into unless, and until, the HRA Conformity Check has been completed. If necessary, amendments will be made to the draft Wind Farm AfL shared with Bidders at ITT Stage 1, to address the outcome of the HRA Conformity Check.

Those who qualify for ITT Stage 2 will begin the Auction process, where a PDA will be awarded to the Bidders who submit the highest annual Option Fee Bids for each PDA.

Bidders who are armed with information revealed by RockWave Repurposing, could more confidently cap the amount they are willing to bid on a PDA with respect to the interpreted subsurface risks, or perhaps choose NOT to bid, deeming the subsurface risk too high.

Knowledge is power.

The Future of Celtic Sea and 12GW

Round 5 is expected to be the first phase of development in the Celtic Sea, with the UK Government confirming as part of its Autumn Statement in November 2023 its intention to unlock space for up to a further 12GW of capacity in the Celtic Sea.

It is presumed these additional 12GW will be found by going back to the 11, of seabed covered by the five “broad areas of search” as previously identified by The Crown Estate's spatial refinement process. There would likely be a long lead time for covering such a large expanse with a shallow seismic 2D vessel at a 250m line spacing, that would only achieve a 50m penetration.

RockWave Repurposed O&G seismic data provides regional coverage, optimised for resolution within the top 100m below seabed and signal penetration even deeper. Existing users of our Celtic Sea data cite the value in interpreting the solid rock geology, as the Repurposed O&G seismic shows where in the sequence you are given the anticline/syncline structures – you wouldn’t get this to the same degree from UHRS.

oil and gas seismic data repurposed for offshore wind in UK waters
Figure 3: Example of RockWave's Repurposed O&G Seismic

We would anticipate that further refinement and time saving would be made possible by undertaking a regional update to soil thickness maps using the modern data that is available now.

Should you wish to get ahead of the competition, speed up your decision making process and gain control of the Celtic Sea subsurface, then contact RockWave today.

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