Watch the webinar replay here, or scroll down for a summary and a preview.
Jeff Vickers (Technical Director, thinkstep-anz) and Tim Kleier (Sustainability & Policy Director, Concrete NZ) discussed the latest developments in decarbonisation of New Zealand’s cement and concrete sector.
What we’ve learned in this webinar:
Here are eight key takeaways from the webinar that highlight both the progress and challenges in New Zealand’s journey to decarbonise its concrete industry.
1. Concrete contributes significantly to emissions due to its large-scale use
Concrete is a highly versatile material with durability, resilience, and low embodied energy. While its emissions per unit are relatively low, its widespread use contributes to a significant environmental impact. The industry's challenge is to decarbonise while maintaining these benefits.
2. New Zealand’s industry is targeting net-zero emissions by 2050
The New Zealand concrete industry's roadmap aims for net-zero carbon emissions by 2050. This involves reducing direct and electricity-related emissions (scope 1&2) 44% by 2030 compared to 2020 levels. It aligns with global efforts but also considers that New Zealand is starting from a different point to other countries: electricity is already highly renewable, uptake of supplementary cementitious materials (SCMs) has historically been low, and earthquake risks places constraints on building design.
3. GCCA roadmap shaped New Zealand’s decarbonisation strategy
The GCCA’s decarbonisation roadmap from 2021 significantly shaped New Zealand’s strategy. The roadmap focuses on various emissions reduction strategies, such as alternative fuels, cement production improvements, and carbon capture, utilisation and storage (CCUS).
4. NZ has limited local production and use of SCMs
New Zealand lags behind other countries in the use of SCMs, which can replace a portion of cement in concrete and help lower carbon emissions. Limited local production of SCMs like fly ash and slag has contributed to this. However, local processing and use of imported SCMs has accelerated significantly in the last few years.
5. Increasing the use of biomass and alternative fuels
One strategy for reducing emissions in clinker production, the most carbon-intensive part of concrete manufacturing, involves increasing the use of biomass and alternative fuels. Biomass is already being used to manufacture clinker (the primary material in cement) in New Zealand, but there is room to do even more.
6. Slow uptake of low-carbon concrete
The uptake of low-carbon concrete is slow in New Zealand, largely due to limited familiarity among engineers and architects with SCMs and their impact on concrete performance. More education and hands-on experience with SCMs could help overcome this barrier.
7. CCUS remains a key strategy for reducing hard-to-eliminate emissions
CCUS is viewed as a critical solution for addressing emissions that are difficult to eliminate, particularly in clinker production. More than half of the emissions from cement production come from direct releases of carbon dioxide in the chemical process used to manufacture clinker. These emissions cannot be eliminated simply by transitioning to renewable fuels and renewable electricity.
8. Life cycle approach highlights the need for collaboration.
The New Zealand concrete industry’s roadmap incorporates a full life-cycle perspective, including scope 1 (direct), scope 2 (electricity) and ecope 3 (indirect) emissions, covering manufacture, distribution, use, and end-of-life processes. This broader view highlights the need for collaboration across industries to truly reach net zero carbon emissions.