New Solutions Emerge for Embodied Carbon in Buildings

Heliogen, a clean energy startup, recently made a promising step toward addressing embodied carbon in cement, steel, and other building materials was. The company announced it can harness solar power to generate industrial heat above 1,000 degrees Celsius using artificial intelligence (AI) and a field of mirrors. The use of AI gives the company a competitive edge, as the software trains a field of mirrors to reflect solar beams to one single spot. Energy storage and proving ROI are key to the success of scaling this solution.

Greater use of wood in building construction is another option to decarbonizing building materials that is gaining attention. Mass timber—wood joined together to form larger pieces—has been gaining favor among architects and advocates as a sustainable alternative to concrete and steel in both smaller and larger building applications. Mass timber comes in many forms and has multiple benefits, including resistance to fire, superior resilience in earthquakes, and faster, less wasteful construction. Scaling the solution requires sustainable forestry practices to ensure greater wood use in construction achieves a net carbon reduction effect.

In addition to innovation in industrial heat technology and construction materials, movement is also happening on the procurement side. Awareness is low but growing among building engineers and architects. Tools are becoming available to estimate embodied carbon in new construction. One such tool was launched at Greenbuild 2019 by the Carbon Leadership Forum. The tool, Embodied Carbon in Construction Calculator, is free and open-source. Unlike existing tools, the calculator is “focused on the specification and procurement phases of projects, allowing the comparison of similar materials from different suppliers,” according to the press release.

The Challenge of Decarbonizing Industry

While most attention in decarbonizing the economy has so far been focused on transportation and power generation, buildings are responsible for approximately 40% of global greenhouse gas (GHG) emissions worldwide. Building operations such as heating and cooling constitute the largest part of this effect. However, embodied carbon from concrete, steel, aluminium, iron, and other building materials represents a large portion as well—11% of total global GHG emissions.

Historically, there has been little movement in this area of decarbonizing the economy. The industrial heat required to produce these materials is one of the toughest issues to address given the high temperatures needed. The industry is also not a consumer-facing sector and is often protected by governments due to its critical nature in defense and infrastructure. Additionally, industrial facilities are built for the long-term, have minimal turnover, and are highly process-specific.

Efforts to reduce the GHG effects of these products have so far included energy efficiency improvements during production, material recycling, and use of complimentary materials with traditional construction products. At the production site, decarbonization options include carbon capture, hydrogen, nuclear, electricity, and biomass. However, all of them are highly expensive, not readily available, and do not fit all applications.

The Toughest Challenges Can Be Solved

Reducing embedded carbon in steel, cement, aluminium, and other metals is one of the most challenging aspects of climate change mitigation. These materials are ubiquitous in buildings and contribute to a large portion of worldwide carbon emissions. Solutions to the problem have been scarce and not highly viable from technological and price standpoints. However, the recent flurry of announcements demonstrates that the challenging issues of decarbonizing are finding technological and behavioral solutions. It is unclear how much acceleration can be expected from policies, corporate investments, and demand side forces. However, these new innovations should provide a solid footing for scaling carbon-reducing solutions in the near- to mid-term.