Like many good things in life, wind turbines don’t last forever. But disposing of retired turbine blades has become a headache for the renewable energy industry. They’re made of materials that can’t easily be recycled.
But from cycle shelters to bridges, life-expired blades are finding innovative new uses around the world. And the first 100% recyclable turbine blades have just been produced in Denmark.
Up to 85% of an existing wind turbine, including the steel mast and electrical components made of metals like copper, can be recycled, but not the turbine blades, which already account for 10% of Europe’s fibre-reinforced composite material waste.
The University of Strathclyde estimates that by 2050 there will be 2 million tonnes of wind turbine waste needing safe disposal globally by 2050.
In the past, blades which include fibreglass or glass reinforced polymers (GRP), have been dumped in landfills or incinerated. Germany has already banned composite materials from landfills and other nations are also imposing full or partial bans.
Recycling for cyclists
The Danish port city of Aalborg, where the new recyclable blades are being made, has found an innovative new use for old blades, by turning them into bike shelters for the city’s cyclists. The materials that make the blades hard to recycle also make them durable and strong.
Nine out of ten Danes own a bike, and cycling accounts for a quarter of all journeys of under 5km in the country. But the Scandinavian climate can be hard on bikes left out of doors, especially in winter.
In Ireland, which will have 11,000 tonnes of decommissioned turbine blades to dispose of over the next four years, University College, Cork has come up with a plan to use some of them to build a bridge on a greenway – a 22km path and cycleway on the track of an old railway line.
The designers say that as well as being structurally strong, the blades’ gentle curves will add an aesthetically attractive feature to the 5 metre span bridge across the Midleton to Youghal Greenway in East Cork which is due to open in 2023.
In the UK meanwhile, retired blades are being used in place of steel to reinforce concrete walls by contractors building the country’s new HS2 high speed rail line.
“Reusing old turbine blades reduces waste, cuts demand for new steel and reduces the carbon generated during the production of concrete,” said HS2 innovation manager Rob Cairns.
“If our world-first pilot project goes well, we could see a waste product from the energy industry becoming an essential material for the construction sector in the future.”
Elsewhere, researchers at the Georgia Institute of Technology in the United States recently used a large section from a 100 metre blade as the roof of a small conventionally built house. Scientists have also tested the properties of decommissioned blades for use as power line poles.
Danish company Vestas Wind Turbine Systems working with Aarhus University has created a process to chemically break down turbine blades to extract epoxy resin plastic from them which can then be used to make new blades.
Meanwhile, Norwegian wind farm builders Akers Offshore Wind and Strathclyde University have devised a pioneering way of extracting the fibreglass from redundant turbine blades for reuse which they say could meet 50% of global glass fibre demand if implemented worldwide.
“GRP scrap is a challenge not only for the wind power industry, but for all industries reliant on GRP materials in their production and manufacturing,” Akers’ Mats Ektvedt told Euro News.
“This includes car manufacturing, maritime vessels, oil and gas production, construction, sporting goods and more. Our focus now is on the recycling of wind turbine blades, but our goal is to develop recovery processes robust enough to handle other kinds of waste,” he added.
The World Economic Forum says 90% of all plastics produced worldwide are never recycled. The Forum’s Global Plastic Action Partnership is working with business and world leaders to end dumping, increase recycling and create a circular economy in plastics.
(Source: World Economic Forum)