Offshore Wind

Offshore wind turbines are made of several major components, each made of different materials:

1. The rotor blades are responsible for capturing the wind energy and converting it into rotational motion and turned into electricity by a generator. To ensure the most optimized energy capture, the material needs to be lightweight and strong at the same time and glass fibre-reinforced composites are the most common choice
2. The nacelle is basically the “brain” of a wind turbine, housing the machinery to convert the rotor’s motion into electricity. The main materials used in the Nacelle are steel, cast iron and copper.
3. The tower and the foundation require a strong and durable structure to carry the weight of nacelle and rotor and are usually made of steel. Most foundations are fixed structures, while floating foundations are emerging for deeper waters where winds are stronger.
4. Several other components are required to connect the wind turbines to the electricity grid, including kilometre-long subsea cables, off- and onshore substations, as well as maintenance and installation vessels and specialised port infrastructure.

As demand for offshore wind rises, so does the need to manage materials more efficiently. Circular‑economy (CE) strategies help reduce emissions by:

• Narrowing material flows (refuse, rethink, reduce)
• Slowing resource use (reuse, repair, refurbish, remanufacture, repurpose)
• Closing loops (recycle, recover)

But in practical terms, what does this means? Here are some offshore‑specific examples:

The composite materials in rotor blades, are challenging to recycle, but promising circular strategies include:

• Using natural fibres such as hemp or flax (Rethink)
• Recycling composites through co‑processing in cement kilns, recovering both material and energy (Recycle/Recover)
• Repurposing blade sections into bridges, furniture, or architectural elements (Repurpose)

Most of a turbine consists of steel and its production is very energy‑intensive and represents the largest share of a turbine’s carbon footprint. Therefore, finding solutions for the towers and foundations are also essential. Some potential improvements include:

• Using concrete instead of steel for towers or foundations, which can lower emissions and be sourced locally (Refuse). However, concrete is more challenging to recycle in closed loops

• Reducing steel mass by using jacket or tripod foundations, though these may be more prone to fatigue leading to shorter lifetimes (Reduce)
• Recycling steel, which is already highly recycled globally (Recycle)

The CO2nstruct project identifies the most effective circular economy strategies for reducing the climate impact of new offshore wind energy and incorporates them into climate mitigation models. This helps us to understand the economic and environmental impacts of a shift to a circular economy. By examining materials, design choices, maintenance strategies, and end‑of‑life options, the project helps support a more sustainable offshore wind industry - and a more resource‑efficient energy transition.

Key references

Mishnaevsky, Leon, Kim Branner, Helga N. Petersen, Justine Beauson, Malcolm McGugan, and Bent F. Sørensen. 2017. ‘Materials for Wind Turbine Blades: An Overview’. Materials 10 (11): 1285. https://doi.org/10.3390/ma10111285.

Prajzendanc, Pawel, and Christian Kreischer. 2025. ‘A Review of New Technologies in the Design and Application of Wind Turbine Generators’. Energies 18 (15): 4082. https://doi.org/10.3390/en18154082.

Velenturf, Anne P. M. 2021. ‘A Framework and Baseline for the Integration of a Sustainable Circular Economy in Offshore Wind’. Energies 14 (17): 5540. https://doi.org/10.3390/en14175540.

Wu, Xiaoni, Yu Hu, Ye Li, et al. 2019. ‘Foundations of Offshore Wind Turbines: A Review’. Renewable and Sustainable Energy Reviews 104: 379–93. https://doi.org/10.1016/j.rser.2019.01.012.