During their lifetime, the use and the exposure to environmental conditions lead to the decay in wind turbine blades. At the end of the useful life (20 years) they can present:
- mechanical and structural decay as a consequence of years of stress and performance
- physical damages from aggressive environmental conditions (ice, rain erosion, sand, thermal hot/cold cycles during day/night and summer/winter, etc.)
meaning that they need to be repaired for the same function (if possible, taking into account that average wind turbines today are far bigger than the ones we had 20 years ago) or to be dismantled/recycled.
A typical wind turbine blade is a structure of a large magnitude in terms of size and weight, and is mostly made of composite materials (typically glass/carbon fibers + epoxy matrix), plus some other minor components/materials (e.g. glue and gelcoat). It is not possible to list the materials percentage or further details, since every blade and wind turbine manufacturer is using materials and compositions that may differ from each other. The most relevant part to be addressed is the composite one (typically glass/carbon fiber + epoxy), that represents more than 90% of the blade weight. The rest is typically adhesive and some other minor-weight materials (also some steel inserts that may be recycled). The sizes and weights of the blades can range roughly from 20 to 80 meters length and 4 to 20 tonnes; smaller ones will be dismantled in the next few years, while for bigger ones the residual useful life is still quite long.
Wind turbine blades installed 15-20 years ago were in the range of 20m (each, so the rotor diameter was around 40m); as of today, an average size for an onshore wind turbine blade is around 60m (solvers should take it as an indication as there are bigger ones). Here below some approximate dimensions of the main sections. Again, they shall be intended as an indication. Solvers can then consider that blades tapers linearly from the max-width section to the tip.
- Blade width/diameter @ blade root:
- 20m blade: 1.5-2.5m
- 60m blade: 4-5m
- Blade width @ max chord (20-30% of blade length, from the root):
- 20m blade: 2-3m
- 60m blade: 5-6m
- Blade width @ tip:
- 20m blade: Less than 0,5m
- 60m blade: Less than 1m
The cost to manufacture each blade varies considerably. The range is 50 -150k€ (old and smalls ones – new and big ones).
Enel Green Power is looking for the best – on a sustainability, effectiveness, and cost perspective – available methods or processes to produce glass wool and/or insulating building materials from wind turbine blades, in order to define a proper business chain to be more and more sustainable, under a circular economy perspective. Alternative uses may be considered if volume of demand is sufficient. The ideal solution envisions the whole value chain within home and building manufacturing, rather than focusing on a specific technology.
Submissions should address the following Solution Requirements:
- guarantee the production of glass wool and/or materials that can be adopted in the building construction sector, such as for example insulating materials (e.g. insulation panels).
- address, at least, the entire material portion of the blades and should not produce any kind of waste. Solutions that can recycle and reuse 100% of the blades’ materials without producing any kind of waste will be rated higher in this requirement. Solutions that cannot achieve this must however address the separation and adequate disposal of the unused materials and components.
- don't produce any type of pollutants that could have a negative effect on the ecosystem.
- cost-effective and has to take into account the total cost of recycling (life cycle analysis, LCA) compared to the use of the alternative materials available for the proposed new use.
- capable of dealing with large amounts of materials. A wind turbine blade weighs a few tones, each wind turbine has three blades and a wind farm can may be composed of a small number of wind turbines, or more than one hundred. Therefore the total amount of material from a single wind farm can easily reach up to 1000 tones or far more for the big ones. Therefore Enel Green Power is seeking sustainable disposition solutions for several hundred blades at multiple project locations in various countries. The proposed solution must therefore consider and address these amounts of material.
- address, as much as possible, geographically local opportunities for recycle, in order to avoid or minimize transporting the blades for long distances due to the size, weight and scale of the materials (even if cut into pieces).
- be capable of being deployed globally, hence following environmental and safety best practices and taking into consideration laws and regulations for material handling and disposal.
The submitted proposal should include the following:
- Detailed description of the proposed method or process that allows for a feasibility assessment by EGP and includes (but is not limited to):
- A description of all chemical/mechanical/physical processes involved
- Details on the materials/components streams resulting from the process, from a chemical/mechanical/physical point of view
- A description on how materials/components resulting from the process shall be used in the building construction sector
- Reference to any chemical substance applied, if any, and its effect on the product
- A description of any potential waste product resulting from the proposed process and how it should be disposed (the proposed solution should avoid the production of waste)
- A detailed quantitative and qualitative assessment of the environmental impact, of the proposed overall process, on the ecosystem (i.e. any further emissions and/or pollutants resulting from blade transportation, treatments, etc.)
- A description of the necessary infrastructure, logistics to move the blades, and cost calculations would help and shall be added, if possible
- A detailed description of the overall cost of the process, with a focus on its cost-effectiveness
- Data, case studies, patent and journal references or any additional material that supports the proposed solution.
The proposal should not include any personal identifying information (name, username, company, address, phone, email, personal website, resume, etc.) or any information the Solvers may consider as their Intellectual Property they do not want to share.