Function
Once equipment is onshore, there is a motivation to extract maximum value via reuse, recycling, or disposal.
What it costs*
Overall, likely to be a net positive value.
Who supplies them
Delta Marine, DUC Marine Group and Scaldis Salvage & Marine.
Key facts
Currently, different parts of decommissioned onshore wind turbines are reused, recycled, or disposed of, depending on age, condition and material content. There is an established second-hand market for onshore turbines known to be robust and reliable with sufficient fatigue life remaining. The turbines are refurbished and installed on new foundations for operation up to 50% beyond the design life.
Offshore costs and financing mean it is unlikely that offshore turbines will be decommissioned with sufficient fatigue life remaining to be re-installed offshore. Turbines are typically disassembled for recyclable scrap. The majority of nacelle and tower mass has residual value and only small amounts of turbine mass requires disposal. Turbines contain a range of valuable materials including steel, cast iron, copper, aluminium and in the future, permanent magnet materials.
Today, most composite blades cannot be cost-effectively recycled. It is likely that new materials and methods will emerge by the time floating offshore wind turbines are deployed at large scale, as there are a range of projects underway in this area.
Blades are typically made from a combination of glass and carbon-fibre in epoxy- or polyester-based resin matrices, along with polyethylene terephthalate (PET) foam or balsa filler. At the root end, there are steel inserts to provide bolted connection to the blade bearing. There is also typically a copper-based lightning protection system.
So far, blades have been cut up and either sent for burning (in waste to energy or district heating plant), to landfill or for low-grade re-use. The first more easily recyclable blades are however now in use offshore.
Most steel floating substructures, anchors, moorings, substation topsides and substation foundations have high steel content. This can be broken down and recycled as input to the manufacture of new steel components. Synthetic rope used in mooring lines can also be used for other applications. Some substation components may be reused. Others can be recycled, again with relatively low proportion having no residual value and requiring safe disposal.
Concrete floating substructures can be broken down and the aggregate used in other concrete construction.
The cable conductor can be readily processed and reused in a range of sectors. XLPE insulation may be cleaned, dried and ground and recycled as filler for new power cables or as insulation in lower voltage cables or accessories.