Wind turbines can be recycled environmentally: IIT Mandi researchers

13 Oct 2022 CW Team

Microwaves have reportedly been used successfully by researchers at the Indian Institute of Technology Mandi to recycle polymer composites from used wind turbine blades in a quick, long-lasting, and relatively eco-friendly manner.

Polymer composites, which are typically polymer systems in which fibres like glass and carbon are incorporated for strength, are used to make the blades of wind turbines.

To recycle Glass Fibre Reinforced Polymer (GERP) composite waste, the team has developed a Microwave Assisted Chemical Recycling (MACR) procedure that is environmentally friendly. Microwaves were used to speed up the chemical breakdown of GERP composites using acetic acid and hydrogen peroxide.

The procedure is particularly unique because both hydrogen peroxide and acetic acid are environmentally friendly chemicals.

The researchers found that their method had a 97.2% epoxy decomposition rate while recovering the glass fibres. In comparison to virgin fibres, the recovered fibres had more than 90% of the other mechanical properties and nearly 99% of the strength.

“The recycling method that we have developed can lead to a profound shift in recycling technologies, which can help the country move towards a circular economy for wind turbines blades,” Venkata Krishnan, Associate Professor, School of chemical sciences, IIT Mandi, said.

With a total installed wind power capacity of 40.8 GW at the end of Q2 2022, India will be the fourth largest country in the world for the installation of wind energy systems. India's wind energy potential is still largely unrealized.

According to a recent resource assessment by the National Institute of Wind Energy (NIWE), the country has a total wind power potential of 302 GW at hub heights of 100 metres and 695.50 GW at 120 metres.

Recycling might be seen as a promising solution as India struggles to repower outdated wind projects.

The decommissioned structures of these glass fiber-based turbine blades are destroyed, landfilled, or burned when they can no longer be used. These disposal techniques increase costs and environmental pollution. It almost negates the environmental advantages of wind energy. Furthermore, the cost of these composites used in wind turbine blades may increase due to landfill disposal restrictions and fluctuating raw material prices.

According to a report, ‘Capturing Green Recovery Opportunities from wind power in Developing Economies,’, the wind energy could bring in $18 Billion gross value to India’s economy.