A former wind turbine blade has been repurposed as a bike shelter in Aalborg, Denmark, and blades have found a second life in a playground in Rotterdam in the Netherlands. In the UK, the Skanska Costain Strabag joint venture is looking into swapping steel rebar for sections of retired glass-fibre-reinforced polymer turbine blades to strengthen concrete in low-stress structures such as temporary access roads and the top sections of concrete walls.
These projects provide a sharp contrast to images of hundreds of blades piling up at a municipal landfill in the US state of Wyoming contained in a 2020 Bloomberg news agency report highlighting the problem of blade waste.
Just what happens with turbine components at the end of their lifetime will be increasingly important, as a growing number of wind farms are fully repowered with new machines, revamped with more up-to-date components or decommissioned.
Some 85-90% of the mass of wind turbines is composed of materials that are easily recyclable — including steel, cement, copper, electronics and gearing — and have well-established procedures for doing so. The blades are more difficult, as they are made up of composite materials that enable them to be light, aerodynamic and resistant, but are difficult to recycle.
In Europe, trade body WindEurope expects around 25,000 tonnes of blades will reach the end of their operational life annually by 2025, led by decommissioned blades from Germany and Spain, followed by Denmark. It anticipates this could double to 52,000 tonnes a year by 2030, as Italy, France and Portugal also start to decommission blades in significant numbers.
A 2017 study by Cambridge University researchers estimated that there will be a cumulative 43 million tonnes of blade waste worldwide by 2050, with China possessing 40% of the total, Europe 25%, the US 16% and the rest of the world 19%. With a greater number of older facilities in its wind fleet, Europe is seen as having to address the problem first.
Landfills are not the main destination for blades from decommissioned wind farms in Europe. There continues to be a strong market for second-hand turbines in eastern Europe and other parts of the world, while some operators will also keep old turbine parts on hand to service other wind farms in a country, notes Ivan Komusanac, an analyst for markets and wind energy technology at WindEurope.
The industry is working to make sure landfills do not become an alternative to more sustainable solutions in the future either. WindEurope has called on the European Commission to ban the use of landfills for blades and other large composite components by 2025 to help accelerate the development of sustainable recycling technologies. Germany, Austria, the Netherlands and Finland already have landfill bans, but the practice is allowed in other European countries.
In October, Swedish developer Vattenfall said it would immediately ban the landfilling of end-of-life wind-turbine blades while committing to recycle half of them by 2025 and all of them by 2030.
Recovery and recycling
Germany, where sending blades to landfills has been off limits since 2005, has led innovation efforts. At its plant in Lägerdorf, building-materials supplier Holcim has used wind-turbine blade waste to generate heat and ash to help make cement for more than a decade.
The practice is now coming to the US, after GE Renewable Energy in December 2020 teamed up with Veolia to use blades from its onshore turbines in the country that are being upgraded and repowered as raw materials for cement manufacturing.
GE pointed to an analysis conducted by Quantis US, showing that blade recycling results in a 27% net reduction in CO2 emissions and 13% net reduced water consumption compared with traditional cement manufacturing.
Making turbines that can be recycled is a priority for the industry. Siemens Gamesa in September launched its RecyclableBlade, which it claims is the world’s first blade that can be recycled at the end of its lifetime and is part of its efforts to make all its turbines recyclable by 2040. The blade uses a resin with a chemical structure that makes it possible to separate the resin from other components at the end of its working life, facilitating recycling.
The first sets of blades are slated to get a real-life test at RWE’s Kasaki offshore wind farm in Germany, expected to begin operations in 2022, while EDF Renewables and Wpd plan to install sets of the blades at future offshore wind projects.
Vestas is now aiming to have fully recyclable blades by 2030 and is targeting a 2040 date for eliminating non-recyclable waste from the manufacturing, operation and decommissioning of its wind turbines. The company has teamed up with epoxy producers and academic institutions to develop an epoxy resin that will be key to making thermoset composites used to make blades recyclable.