WECHULL+

Objectives 

The main objective of WECHULL+ is to demonstrate (TRL4-6) a new, sustainable, circular and reliable concrete material suitable for floating substructures in the offshore renewable energy sector; to model, test and validate it in the real ocean environment. WECHULL+ objectives and activities are based upon the learnings and proof-of-concept (TRL4) of a new sustainable concrete mix with high-performance in marine environment, carried out within the WECHULL project (TRL4). WECHULL+ takes these efforts to a European level, where experts in the field of material sciences, predictive modelling, field testing, critical loads assessment, biofouling, technology development, extreme load analysis, social sciences and environmental impact assessment, are brought together to validate and verify the WECHULL+ concrete material and its real application through sample ant prototype testing (lab and ocean).

Challenges addressed

The traditionally used steel is expensive and prone to corrosion in the harsh marine environment. Composites price are even higher than steel, are fossil-fuel based, their manufacturing is characterized with high environmental impacts and they still lack data on long-term performance in sea water. Therefore, the blue energy sector is currently looking into concrete. Concrete is an inexpensive (in the range of 100 EUR/ton – 30 times lower than steel and 50 times lower than carbon fibre reinforced composites), marine environment resistant, and easy and fast to fabricate on-site (casting) rather than the traditional alternative to traditional manufacturing material. Concrete, the most used material in the world after water, is also a material with a mature value chain which enables using local production worldwide. This is a particular advantage for Offshore Renewable Energy (ORE) installations, often planned in specific sites due to favourable ocean conditions, far from the main supply chains, or being close to islands without connections to the continental energy network. 

Despite its long history, concrete technology is still active and growing area of research and industry. The continuous progress is created by designing new mixes, replacing binders and aggregates with alternative ingredients and/or adding dedicated chemical modifiers. Also, concrete is responsible of 6% of all the CO₂ footprint worldwide. The main contributor to CO₂ of concrete is cement. By using climate-optimized concrete material (including waste and recycled materials as well as alternative bio binders) can greatly reduce concrete CO₂ footprint on the material level. 

Results and impact expected 

The expected outcome of WECHULL+ material development is to design a set of mixes based on local raw materials, improve circularity of the material and confirm its reliability in different climate zones in Europe. The WECHULL+ material and modelling solutions will be possible to apply in all types of floating substructures for offshore renewables energies but also for other users such as and aquaculture. The high-strength concrete achieves 70 % of its final strength after 24 hours, which enables demoulding and towing to the installation site almost immediately after manufacturing. Maintenance of WECs contributes to up to 30 % of OPEX and therefore, is one of the largest factors to reduce LCOE. The WECHULL+ project supports the offshore renewable energy transition by supplying the industry with: 

• New robust (>100 MPa in compressive strength, self-damping, noncorrosive and antifouling properties) and 
• Sustainable materials with 70% less carbon footprint then steel 
• Lower the manufacturing time to be below 5 days 
• Supports local manufacturing and local supply chains
• Lower the overall LCOE by 25%

Project website

www.wechull.se