GUEST COLUMN:
Martyn Fear
Managing Director
NCF
Every construction product begins with a materials decision. What goes into a block, a wall or a building determines not only how it performs, but how much carbon is locked into the process before anyone moves in.
That is why the ash at Aberthaw deserves a practical commercial conversation. The former power station site holds an estimated 18 million tonnes of pulverised fuel ash, or PFA, the fine ash produced when pulverised coal is burned in a power station. It sits in a 50-metre-high mound across the site and has prompted discussion about cement, mineral extraction and other future uses.
The immediate question is what can be made from it. If this material can be used to make building blocks and other construction products, the work now is to prove the product, secure the approvals and build the manufacturing route that gets it into the market.
I have spent more than 50 years in the concrete industry, much of it in precast concrete. That shapes how I look at a material like this. I am interested in analysis and research, but I am more interested in whether a material can be turned into something useful, made at scale, sold into the market and used in real buildings.
My business, NCF, was set up to develop low-carbon construction products. Our work has looked at whether materials categorised as waste can be used to make practical building products, including blocks. The approach is deliberately grounded. We make products first, then prove and validate them, because if something does not work in manufacture, the science alone will not carry it into the market.
The usual discussion around ash often starts with cement replacement. That is a recognised route, and it may form part of the answer at Aberthaw. But the ash on this site has a high carbon content, and the economics of removing that carbon can be challenging. My view is that we should also ask whether the ash can be used as it is.
That is the route NCF has been exploring. Rather than starting by taking carbon out of the ash, we have looked at how to activate the material in its raw state and use it as a binder. That requires a different activator from those commonly used elsewhere, but the principle is simple: use the material that is already there, avoid unnecessary processing, and make a product that can meet a real construction need.
We have already made blocks. These are not theoretical products. They are standard construction items made through a process that exists and can be scaled. There will be regulatory approvals to secure, as there should be, but because we are talking about blocks rather than large structural elements, the route is less complex than it would be for some other applications.
Building blocks are not niche products; they are common, hard-working materials used in everyday construction. If the ash at Aberthaw can be used in that kind of product, then we are no longer talking only about future ideas. Instead, we are talking about a route into the market which could begin creating income, supporting development and showing what this material can do.
There is also a wider construction point. Homes and buildings need to be designed for the conditions they will face in the future. Traditional forms of construction still have a great deal to offer when used properly. Blocks can provide thermal mass, help manage heat, and perform well around fire and flooding. A lower-carbon block that looks familiar to the market, but is made from materials already available to us, is a commercial proposition worth pursuing.
The circular economy only works if it becomes practical. If ash can be used as a binder, it may also help encapsulate other waste materials within construction products. We have worked with other waste streams, including material from the NHS, to explore how aggregates can be replaced in block manufacture. That opens up a broader question about how materials currently treated as waste can be brought together to make useful construction products.
I do not like the language of subsidy in this context. If a product only works because it is subsidised, the commercial case is weak. Development is different. A product that can be made, sold and improved can generate income, support further work, and help fund the research needed to explore other routes for the ash, including higher-value applications.
That is the sequencing I would like to see. Start making something useful, use the rewards from that activity to support further development, and bring academic knowledge, industry experience and commercial delivery into the same room so that the work does not split into silos.
The science is important, but so is the ability to manufacture, test, certify and sell a product.
There are several routes for the Aberthaw ash, including mineral extraction, cementitious uses and other advanced materials, and those should continue to be explored. But they should not prevent practical products from being developed where the work has already been done and the market need is clear.
Commercial discipline will be essential. There has to be money flowing through the system, because without that, the wider circular economy ambition will not sustain itself. The approach also needs to be broad enough to serve the common good as well as individual commercial interests. If the strongest organisations pursue only the narrow routes that suit them, the fuller value of the material may be missed.
Aberthaw can become a model for using ash and other waste materials in construction products, beginning in Wales and then informing approaches elsewhere in the UK. It can support housing, jobs, manufacturing and further research, while showing how a legacy material can be put to work.
