The NetZero Road has many Lanes

The world needs concrete. Cement and concrete are essential to the world’s urban infrastructure development. As cities are built and the world prepares for the inevitable climate commitments, it must also be acknowledged that the cement industry represents 7 – 8% of the world’s greenhouse gas (GHG) emissions, significantly contributing to these challenges. Here is the challenge: the world needs to build but it must decarbonize.

The question is, how does the industry meet this challenge? In some ways, it is simple for the cement industry – it is all about clinker manufacturing, the key source of GHG emissions. Global industry players must:

• Avoid carbon emissions by replacing carbon-emitting materials in clinker, or produce this clinker with lower emissions.
• Use clinker cement sparingly and efficiently, and capture the rest and use or store the carbon.

Or, more simply still: replace, reduce, be efficient, and capture – the underlying logic of the Roadmap to NetZero outlined in Table 1.

Table 1: The five C’s of cement & concrete decarbonisation.

However, it is useful to group these industry solutions into three lanes: producer control, supply chain collaboration, and innovation partners.

Lane 1: Cement producer controlled actions
The industry has many known and proven solutions that are available but rarely fully under its control, such as replacing fossil fuels with lower carbon fuels and replacing older technologies with more efficient, modern alternatives. Both strategies yield cash savings through efficiency and profit-producing tipping fees where low-carbon fuels are produced from waste. Use of supplementary cementitious materials (SCMs) can be expanded.

These make sense on their own and GHG reduction is a nice byproduct.

The challenge here is pace of change and access to capital in the global competition for investment. An ability to monetize GHG reductions through carbon pricing, carbon markets, tax breaks, or granting programs will accelerate the implementation of these solutions, which are some of the most straightforward available to the cement industry.

Nonetheless, these clinker and cement modifications only take the industry partway down the road — for example roughly 30% per ton of cementitious product for the Canadian industry (see Concrete Zero report). The good news is that these steps are straightforward as the industry can 'do it alone,' especially with the addition of supportive carbon policies.

These investments yield a 'like for like' cement product flowing through to decarbonized buildings – with modest cost increases for builders and little need for change in their practices.

Lane 2: Supply chain collaboration actions
The next suite of solutions will require the building industry as a whole to change its practices. Without a doubt, this will be a much harder lift.

The Concrete Zero report notes that nearly an additional 40% reduction in embodied carbon is possible through the 'Concrete' and 'Construction' strategies. They require deliberate collaboration and planning up and down the building supply chain – conversations that do not happen today. In the absence of any incentives such as green building standards or carbon pricing, the pace of progress here will be painfully slow.

Some early wins are emerging where smart construction design using modern computational design techniques places the right strength concrete in the right places. All too often, for example, an entire pad is poured with the highest strength concrete, when only a portion of the pad is needed at that strength for structural needs. Smart design ultimately reduces clinker content, the most significant cost driver (and carbon emitter) in concrete. Even then, this requires new practices and new placement techniques in an industry that is resistant to change. A theme is emerging that pilot projects with willing partners are needed to start to change these practices.

Another example is the use of performance standards that enable sophisticated mix designers to deliver concrete tailored to the specific needs of the project, while achieving much lower embodied carbon content – often at little to no price premium, and even deeper reductions with larger price premiums. The ASTM C1157 standard is an example of a performance standard. However, including this approach in other national and international standards will be slow due to resistance to change. Embedded instrumentation may reduce risk and, again, pilot projects can help change practices.

Deeper embodied carbon reductions may require the builder to accept ever larger price premiums and risk-sharing mechanisms that are far from the industry norm. Will Concrete Formers be prepared to wait longer for a target strength to be reached in a tight building schedule? Can embedded instrumentation be used here too to remove uncertainty?

Understandably, engineers and architects are cautious when new building solutions emerge and are slow to adopt them – particularly when there is no apparent project or personal benefit, apart from decarbonization, at play. Fortunately, Green Building or Green Procurement Standards are emerging, creating a market incentive for low-carbon solutions. These approaches will drive cooperation between the cement and concrete supplier, the constructor, the engineer, and the owner to find the trade-offs that ensure affordability and safety while also decarbonizing the built environment.

So far, the focus has been on carbon intensity and emissions per unit of product. The decarbonization matter becomes much more daunting when absolute or total emissions are considered – and, frankly, this is the important measure. Assuming a 2% annual growth in concrete usage, over 10 years, corresponds to a 22% increase in production partly offsetting emission intensity reductions. It is worth noting that if the pace of decarbonization outstrips the pace of growth, then clinker production will decline, which is where the actual GHG savings will occur.

Lane 3: Innovation partners
Assuming, optimistically, that these first four 'C's (of decarbonization) are implemented in the next 10 years, then achieving the last 25 – 30% to net zero remains the billion-dollar question.

There are not too many problems that a billion dollars cannot solve. A reasonable cost estimate for standalone CCUS projects (CCS, eFuels) is US$1.5 billion for one cement plant; but even if US$1 billion is saved with further innovation, that still represents over US$2.5 trillion in investment for the global cement industry. Avoiding or reducing this overwhelming cost is where innovation must come in, especially in the absence of an offsetting strategy. Whether through innovatively reducing the cost of CCUS technologies, creating new partnerships with other industries to share costs, or finding ways to produce cements without clinker, the industry needs partners to reach this goal. The good news is that novel innovations in this industry are being announced every week, and in time, there is good reason to believe that solutions will be found.

Getting into gear
Here is a practical yet aggressive approach. Implement the actions that are under the control of the industry, responding to the carbon price as a short-term text, and work jointly to create the policy environment that fosters supply chain collaboration and innovation. This will mean doing the groundwork to ensure strong governance, robust carbon accounting practices for fuel saving played, a shared lexicon, adoption of performance standards, and an innovative culture of low carbon innovation. Find partners to lead the way with pilots.

Lastly, the industry must pursue a policy environment that positions the sustainable path as the profitable path while providing affordable building solutions. The industry simply cannot reach NetZero by 'doing it alone' and therefore needs to reach out and urgently pursue partners to ensure it continues to build for people and the planet for the rest of the century.

References

1. ConcreteZero: Canada’s Cement and Concrete Industry Action Plan to Net Zero – https://cement.ca/sustainability/concrete-zero