Phasing out coal has big implications for the circular economy in construction, but it also presents a big opportunity.
The decision to phase out coal-fired power stations in the UK by 2025 will have far-reaching implications for all kinds of industries and construction is no different.
It’s no surprise that their demise will reshape our future energy mix, but it could also provide a much-needed shot in the arm to the construction sector’s efforts to embrace a circular economy – where more building materials are recovered and regenerated at the end of their service life.
Catalyst for change
For many years, by-products from coal-fired power stations have provided an important and high-quality source of material for the manufacture of a number of construction products.
Take plasterboard: in 2014, more than 75 per cent of these products in the UK were produced using desulphurised gypsum (DSG), a by-product of the flue gas desulphurisation process in coal-fired stations.
Re-using this material stream has helped our industry reduce its reliance on natural gypsum to become more resource-efficient. It has also helped operators of coal-fired stations avoid sending DSG to landfill.
It’s been a win-win situation. But with the phasing out of coal-fired power, what happens now?
“The demise of coal-fired power, and with it a high-quality source of by-product gypsum, needs to be a catalyst for the industry to speed up the transition to a circular economy or closed loop process”
An unsustainable option would be for our industry to simply revert to using more mined natural gypsum. That is wasteful, particularly as gypsum is a unique material that can be infinitely recycled.
Over the past few years we have taken significant steps as an industry to embrace a circular economic model – increasing the recovery and recycling of gypsum from plasterboard at the end of a building’s service life so it can be a central component in the manufacture of new plasterboard products.
Critically, the demise of coal-fired power – and with it a high-quality source of by-product gypsum – needs to be a catalyst for the industry to speed up the transition to a circular economy or closed-loop process.
Seize the opportunity
So what needs to happen to help the industry maximise this opportunity? The principal findings of Gypsum to Gypsum, a three-year EU-funded research project, provide clear recommendations.
While this study has focused on one material, many of its findings shed light on issues and practices that will benefit the wider construction industry.
Firstly, the study found that a fully functioning closed-loop industry cannot be the responsibility of one operator in isolation. Construction and demolition companies, waste collectors, recyclers and manufacturers all have to collaborate to achieve this goal.
A second recommendation is that, at the end of a building’s life, we need to deconstruct rather than demolish. That’s because when we demolish, the gypsum in plasterboard all too often gets contaminated, making it difficult to recycle.
Deconstruction and sorting waste at site is a controlled and precise process that decreases the risk of contamination and allows gypsum to be salvaged and sent for recycling.
“The increased costs are outweighed by the economic and environmental cost savings of avoiding gypsum waste disposal”
Third, we need to make deconstruction audits for buildings of more than 1,000 sq m mandatory, not just best practice.
These should be produced prior to a building’s construction and demolition, and provide a detailed inventory of its materials, setting out the scope to recover and re-use them at the end of the building’s lifecycle. Making these audits common practice should help ensure we design, specify and build for recyclability.
The final finding is that controlled deconstruction in the UK is cost-effective and delivers a net gain. Yes, there may be higher labour costs to sort and segregate materials on site and to transport them to a recycling centre, but these are outweighed by the economic and environmental cost savings of avoiding gypsum waste disposal.
Greater supply chain collaboration, a commitment to deconstruction and auditing, as well as a clear focus on designing buildings for long-term recyclability – all of these things should power our approach to the circular economy in a post-coal-fired era.
Steve Hemmings is head of EHS & sustainability at Siniat