Mooring solutions for large wave energy converters

The Danish wave energy sector consists among others of several large floating wave energy converters (WECs). All these WECs need to have specifically designed mooring systems, as “standard” solutions (coming generally from the offshore oil and gas industry) are not well suited for the conditions and specifications of WECs. For these it is of importance to reduce the resulting mooring and structural loads rather than avoiding motions, which can be done by increasing the mooring compliance. This will reduce the cost of the mooring solution and structure of the WECs, and thereby the overall cost of the WECs and their produced energy, while making the systems more reliable.

The four WECs that have been selected to be part of this project are all at the offshore prototype development stage and are more specifically Floating Power Plant, Wave Dragon, Weptos and Leancon. They all require similar mooring solutions, as they are large floating structures operating at intermediate water depths (30 – 100m) at commercial scale deployments. The project aims at investigating and comparing different mooring solutions useable for these large WECs. The mooring solutions will be assessed step-wise in order to have a very systematic and rigorous evaluation. The project consists of the following work packages:

- WP 1: Design practise and tools.
- WP 2: Mooring cases.
- WP 3: Preliminary design.
- WP 4: Full experimental and numerical analysis.
- WP 5: Cost evaluation.
- WP 6: Selection and results.
- WP 7: Dissemination and project management.

At various steps throughout the project, reports will present the findings of the investigations and milestones, according to the project Gantt diagram. Each of them will be decisive for the next step in the analysis and will thereby be a great importance. The outcomes of this project are numerous. It will provide experience and insight into the development of mooring solutions to all the partners, as well as others developing similar types of floating structures. Furthermore, it will provide the partner WECs with detailed analyses of these various mooring solutions, which will make them useable in practice. Aalborg University will gain a lot of experience and know-how in the field, which will make them, or a possible spin-off, capable of offer this kind of services to other companies in the future.