Recycling Waste Wind Turbine Blades for Low-Carbon Concrete (WINDCRETE)

Central to the UK's ambition to achieve Net Zero is the increasing transition to renewable wind energy. To achieve this goal, the UK has set out a Ten Point Plan for a Green Industrial Revolution which places offshore wind at Point One in its energy strategy. Already a global leader, the UK aims to generate 50% of its electricity using wind power by 2030, nearly doubling its current output.

However, the UK is facing a compelling challenge of dealing with massive amount of waste blades while benefitting from wind power. The lifetime of wind blades is 25 years. It is estimated that around 5,200 blades of ~34,400 tons will be decommissioned in the next 5 years in the UK and this number will increase by 10 times by 2050. By then, Europe will have 325,000 waste blades. It is estimated that 43 million tons of waste blades will be decommissioned globally by 2050, making it a pressing national and international issue.

The wind turbine blades are predominantly made of fibre glass composites comprising glass fibres embedded in a polymer resin (e.g. epoxy). These composites are engineered to be very tough, making them extremely difficult to decompose in the natural environment. Unfortunately, the current recycling methods are either energy intensive or too expensive, leaving the waste blades to be landfilled or incinerated creating serious environmental problems. Some European countries have banned landfilling waste blades through legislation and the UK is expected to follow this trend.

Construction industry is also facing a critical environmental issue because the production of cement (as the key constituent of concrete) is an energy intensive process with huge CO2 emissions. Generally, producing one ton of cement releases about one ton of CO2 in the air, making cement production account for 8% of global greenhouse gas emissions. The UK construction industry consumed 15,218,000 tons of cement in 2020, and it is in an urgent need of technologies for reducing cement consumption to achieve the Net Zero goal by 2050.

My fellowship aims to develop a completely new and feasible technology to recycle waste wind turbine blades for making low-carbon concrete (WINDCRETE). This is underpinned by my pioneering research which shows that the silica-rich recycled powder from grinding the waste blades is chemically reactive in alkaline solution (pozzolanic reactivity), so that it can replace cement for making concrete. I will develop WINDCRETE into a new construction material through a series of fundamental research in (a) glass and polymer separation, (b) hydration and molecular modelling, (b) pozzolanic reactivity maximisation, (c) strength/durability optimisation and (d) life cycle analysis (LCA).

I have engaged with 9 industrial partners across broad sectors including wind blade manufacturer, cement and concrete producer, construction and designer, waste management, composites trade association and innovator. In close collaboration with industries, I will bring WINDCRETE from the lab to the real world through a startup which is underpinned by two patents developed from this research and successful demonstrations on the partners' construction sites.

WINDCRETE brings an exciting opportunity to address two global issues in both wind energy and construction industries, establishing a new paradigm in recycling waste blades while decarbonising concrete. More importantly, I will generalise WINDCRETE to extend its impact to wider industries like aviation, automobile, marine and electronics, which are using massive fibre glass composites but facing the same challenge of recycling the waste.