The Circular Economy Case for Aberthaw’s Ash

The language we use around industrial materials can shape the decisions we make about them. Call something waste, and the instinct is often to manage it, contain it or move it out of sight. Call it a resource, and a different set of questions follows: what can it become, who can use it, and how do we make sure its value is not lost too early?

That is the starting point for how we should think about the pulverised fuel ash at Aberthaw. Pulverised fuel ash, or PFA, is the fine ash produced when pulverised coal is burned in a power station. At the former Aberthaw Power Station, there is an estimated 18 million tonnes of it, held in a 50-metre-high mound across the site.

For me, the most important point is that this is not simply waste. It is a resource for the future. The material originally came from the ground, went through an industrial process, and now sits in a form that could have further use. Burying it, ignoring it or treating it only as something to be disposed of would not make the best use of what is already there.

My work at PDR, part of Cardiff Metropolitan University, focuses on ecodesign and the circular economy. I am also part of the Circular Economy Innovation Communities project, and I wrote a report on fly ash at Aberthaw more than a decade ago. The world was different then, but the core question remains relevant: how do we use this material in a way that creates the greatest value, not only for today’s markets, but for future generations?

That requires a broader understanding of value. It would be possible to look at PFA only in financial terms and ask how quickly it can be sold into existing markets. That may form part of the answer, particularly where there are established uses which can take material now. But if that is the only measure, we risk missing the longer-term value that could come from lower-carbon materials, future manufacturing applications or markets that are still developing.

Time is central to that decision. If the priority is to move the material quickly, then the focus will naturally be on standard markets which are already able to use it. If there is more time to plan and think through the opportunity, then it becomes possible to explore other routes, including applications that are at an earlier stage of development.

That does not mean choosing between today’s markets and tomorrow’s ideas. A more circular approach would be to think about cascading value. Some of the material may be suitable for established uses, creating income and demonstrating practical reuse. But that should be done in a way that does not close off higher-value options or damage the potential of remaining material to be used in other applications.

This is where circular economy thinking is sometimes too narrow. We often talk about materials, but we should not forget the word economy.

If PFA is used in existing markets now, there is a legitimate question about how the value created can flow back into research, testing and demonstrators that may unlock greater value later. The immediate use of the material and the exploration of future uses should be symbiotic, not separate.

That is particularly important for technologies at low technology readiness levels. Early-stage research can be difficult to fund and slow to scale, even when the science is promising. Public funding has a role to play, especially where what looks like blue-sky research has a real-world application. Aberthaw could sit in that useful space, where an industrial material provides a practical focus for research that might otherwise take much longer to develop.

The challenge does not end at the early research stage. In the circular economy, there is often another gap when technologies are closer to market but still need to prove themselves against incumbent materials. Demonstrators are essential at that point. We need more space and more investment to help promising circular economy applications reach the stage where they can compete properly. At present, it is not always a level playing field.

That point should influence how Aberthaw is approached. The ash may have uses in low-carbon concrete and other construction materials, but there are also emerging opportunities that should not be ruled out too soon. One area that I think is particularly interesting is the potential use of ash in zeolites for carbon capture and storage, a market which is expected to grow in the coming years.

Aberthaw therefore needs more than a disposal plan or a single commercial answer – it needs a value strategy. That strategy should recognise the role of established markets, the importance of reinvestment, the need for demonstrators and the potential of future applications which are not yet fully developed.

If we treat the ash only as waste, the ambition will be limited from the start. If we treat it as a resource, the responsibility becomes greater – but so too do the opportunities. We then have to ask how to use it in a way that creates value today while preserving the possibility of greater value tomorrow.