Delivering on the promise & potential of floating offshore wind (FLOW)

With the 15.5GW Scotwind, recent 5.5GW INTOG round and the upcoming 4GW Celtic Sea leasing round combining with a few pilot, and test & demonstrate projects, there is now a 25GW pipeline of potential floating offshore wind (FLOW) projects across the UK. In physical terms this equates to around 1,500 floating units, each likely to be around 8,500Te each and typical dimensions of H105m x W85m. If you can visualize a floating Eiffel Tower and two VLCC tankers side-by-side, then you can appreciate the scale of a single FLOW unit.

Scale matters as bigger units with bigger turbines equals more power output. On the flip side, delivering #60 or #70 FLOW units for a single 1GW project, and doing this within a 2yr installation window, has some real practical issues. For context, the largest UK FLOW project to date has been #5 smaller units and in overall scale, 1,500 units is about the same tonnage as the entire UK shipping fleet operating today. 

Whilst the practical challenges in growth and scale are legion, the following two examples illustrate solutions that are enabling delivery on the promise and potential of floating offshore wind.

Temporary offshore ‘wet’ storage

Bringing together all the supporting vessels, supply components and activities to install a 1GW FLOW project in two seasons is a major undertaking. Key to this schedule is having your floating units built and marshalled, ready to integrate with their towers, turbines, and blades and then ready to be installed.

But with most ports and facilities only able to handle 2-3 units at a time (remember the physical dimensions), where do you ‘park’ or store your other units? What do you do if you have supply or delivery delays, or the weather conditions slow you down?

Without answering these simple questions, you cannot deliver a robust integration and installation plan. Offshore Solutions Group identified this issue in late 2021 and, partnering with HR Wallingford, set out in 2022 to answer these questions through the Temporary Storage Floating Wind Joint Industry Project (TS-FLOW© JIP).