Wind turbines are transforming the way we generate energy for the better. But because their mixed fibreglass blades are hard to recycle they currently go to landfill. LIFE REFIBRE is paving a new destination for turbines by mixing the plastic with asphalt to build stronger roads and cut waste.
Spain has the second highest number of wind turbines in Europe. Figures from 2015 estimated that these contained 142 000 tonnes of fibreglass, a significant percentage of the total 724 860 tonnes in the EU.
On top of this, the numbers of turbine plants and the size of turbines – and the resulting waste – are on the rise. According to Eurostat, wind power became the second most important source of renewable energy in the EU in 2017.
This trend gives an added urgency to solutions to close the cycle of the non-biodegradable waste that results when turbines are decommissioned. This can happen as the technology improves and wind farms replace older turbines with increasingly efficient newer models, or when they reach the end of their planned life.
The project team estimates that by 2020, 46% of the turbine blades installed in Spain will need to be replaced because they will be over 15 years old.
LIFE REFIBRE is a circular economy project that is showing how the usefulness of these green energy sources can extend beyond their expected lifetime, and how the resulting waste can be used on an industrial scale in road creation and maintenance. Project partners span construction and infrastructure sectors, research and development.
From prototype to the street
In order to deliver the goals of the project, the LIFE REFIBRE team has 2 main activities:
- constructing and running a recycling plant to pre-treat this compound and ready it for mixture with asphalt
- building a demonstration road to test its performance
By February 2019, 12 wind turbine blades had been collected from 7 different locations. As the project becomes more widely known in the area, other companies are offering it ready-dismantled blades.
The team is currently working on pre-treating these materials using a recycling prototype designed by CARTIF, one of the partners, and hosted on the construction site of BLASGON, another partner. Fibreglass pieces are first ground down and then sorted into materials to be used or disposed of.
The resulting fibres together with the asphalt mixtures are characterised according to international standards that determine properties like flakiness and compression.
“We check the different amounts of fibreglass with asphalt mixtures and compare them with regulatory requirements”, explained Bárbara Rodríguez Oraá from Instituto de la Construcción de Castilla y León (ICCL). “The final amounts chosen are those that allow the greatest optimum amount of recycled fibreglass within the normative range.” Properties checked include stability, deformation and density.
Planning permission granted
In February 2019, the project gained planning approval to build a demonstration road in the district of Zamora, Spain. The goal is to lay a stretch of road within the national Spanish road network. Factors involved in choosing a suitable location included how many heavy vehicles use it on a daily basis, and how it fits into its surrounding road network. Monitoring will last for 1 year. The project believes that incorporating fibreglass will lead to a 3-year increase in the lifespan of roads.
“LIFE REFIBRE is perfectly located to test a stretch of road with enough topographical and climactic variety so that results can be extrapolated to other areas in Europe,” said Ms Rodríguez Oraá. “The climate varies between -10C and +40C, so we can evaluate how the asphalt behaves in extreme conditions”
At the same time the region of Castilla y León has many windfarms, so the team can evaluate where the recycling process works best: at the windfarm itself or at the recycling plant, she added.