By Florian Merlet, Senior Floating Wind Engineer at KONGSTEIN
To meet this almost exponential trend, the first gigawatt scale projects have been already awarded (i.e: Scotwind) and several ~100MW are already well advanced. It means hundreds of turbines installed each year in the coming decade.
The first few operating projects have a key role to pave the road to success. Despite a relatively modest number of 30 floating turbines installed so far, precious lessons learnt have already been gained. They are essential to de-risk and optimize the industry.
The KONGSTEIN floating wind experience
KONGSTEIN is one of the happy few companies to hold some of these valuable lessons learnt.
On top of numerous floating wind desktop studies and tender support, we have assisted our clients on-site during the assembly, towing, installation, and maintenance of several floating wind projects, spread across several countries and with different types of floaters.
At KONGTEIN, we believe in the importance of sharing early lessons learnt to benefit the industry. So today we are sharing 3 of them that could apply to any project:
1. Challenging interfaces
Offshore projects have always involved a large number of contractors/suppliers and potentially multiple stakeholders. This is particularly true for floating wind where major packages such as manufacturing, assembly, and installation are highly dependent on each other. Between each of these packages is an interface that can present a risk of delay and expenses for the project.
Therefore, to achieve a flawless and coordinated execution, here are a few principles that can be followed:
- interface management: it is key to understand the risks, responsibilities, and dependencies that are behind each interface. Proper contract management with clear interface matrix, and early stakeholder engagement will be essential during the project.
- package decoupling: try to decouple packages as much as possible. This will help to mitigate the cascade effect of delays from one package to another. This should be one of the key drivers when defining the project T&I strategy. Temporary wet storage of assembled floaters before installation is a great example of such mitigation.
- Contracting strategy: interfaces for developers can be reduced by grouping packages. The risks and interface management will not completely disappear but rather be shifted to contractors currently likely to be more experienced in the management of complex marine operations.
2. The design’s details matter
“The devil is in the details” as we say. Unfortunately, this is no exception for the floating wind. What looks like a small design choice can turn into a larger problem once in the execution phase. Issues like loose fiber lines getting entangled, unfriendly ROV rigging, or non-fitting parts can be avoided.
It is not possible to design perfectly, but the challenge is to spot these problematic details before they make their way to the execution phase. To do so, we recommend the following:
- Perform 3D simulations (numerical and physical) with a sufficient level of detail and based on up-to-date and verified drawings.
- Organise several design firewall sessions at different stages of the project. Favour physical sessions, with sufficient time (days if necessary), where all stakeholders should be present.
- Look for similar past projects/operations and integrate their relevant lessons learnt.
- Do not mind spending extra resources on engineering as mindful engineering substantially reduces risk during T&I and operational phase of the assets.
3. Don’t guess your operational limits
The most important might be the weather limits for accessibility onto the floater. It is the prerequisite to most of the operations, whether you are in construction or O&M phase. Floaters will likely need to be accessed more often and longer than planned. So, we recommend spending extra resources to accurately evaluate their accessibility.
The main elements to be considered are:
- the method and design of access for technicians (CTV, SOV with W2W, Helicopter)
- floating structure type
- Environmental conditions
We recommend an early engagement of the involved stakeholders (developer, service provider, foundation designer, T&I contractor, and access vessel provider)
Other operational limits during assembly, towing or hook-up can also negatively impact the project execution if overseen.
To mitigate it, an accurate assessment of the environmental conditions at all the operation locations (i.e: ports, wet storage areas, towing routes, and offshore sites) is required. Harbour agitation, tides and currents should be included in this assessment. This information should be communicated with the relevant stakeholders (Crane, vessels, ROVs,) and cross-checked with their project specific equipment requirements.
Are you interested in more specific lessons learnt that can directly apply to your project? Get in touch with our Floating Offshore Wind Lead, Tim Mueller (TM@KONGSTEIN.COM).