Variability within life cycle assessment of composites: a limitation of decision making for composite environmental sustainability

Composites are critical for decarbonisation and achieving net-zero emissions by facilitating the creation of the lightweight, high-performance structures essential for efficient transportation and renewable energy systems. However, the production of the materials and the composite manufacturing processes also generate environmental impacts: greenhouse gas emissions contributing to climate change and emissions influencing loss of biodiversity. To mitigate these effects, it is vital to assess the potential environmental burdens of composites through Life Cycle Assessments (LCA). This method has gained widespread recognition within the industry, as evidenced by the marked increase in the number of LCA carried out and published [1]. A close examination has revealed substantial variation across LCA results for composites, raising questions about the sources of this variability and its influence on decision-making regarding the environmental sustainability of composites.

This presentation will address the current life cycle environmental impact assessment values reported across composite LCA studies and will critically assess the quality of Life Cycle Inventory (LCI) data for composite materials [2]. The comprehensive methodology involved developing a data quality assessment methodology, analysing, and critically reviewing existing LCA data and LCI background reports from seven principal databases, with a focus on eight key composite materials and various composite manufacturing processes.

The absence of technical critical reviews emerged as a significant concern. This reflects the low maturity of life cycle assessment, and sustainability assessment level, in general within the composite industry, highlighting the risk of inaccuracies that could undermine LCA outcomes and produce misleading conclusions. The current LCI datasets were found to have fair data quality and major concerns such as dataset completeness, precision, timeliness, and reliability were identified. This assessment uncovered significant variability for both composite materials and composite manufacturing processes [3], notably for carbon fibre, with a wide variance in energy consumption, ranging from 183 to 1350 MJ, and GWP figures from 21 to 89 kg CO2-eq/kg.

Some quality issues may still persist due to the inherent uncertainty in LCA data, which is typical of all scientific inquiries. The role of LCA as a lens in environmental sustainability assessment within the composites industry requires a trade-off between the acceptability of data quality and the communication of LCA data by industry stakeholders with openness and transparency.

There is a significant opportunity for improvement in the quality of inventory data, especially through the inclusion of primary, foreground data from the industry. Establishing a critical review mechanism, involving a panel of stakeholders from both industry and academia, could enhance data reliability. Such a panel could be facilitated by a professional institution or composite trade association. The aim should be to standardise and harmonise LCA methodologies across the field.

References:
[1] Moutik, B., Summerscales, J., Graham-Jones, J. & Pemberton, R. 2023. Life Cycle Assessment research trends and implications: a bibliometric analysis. Sustainability, 15, 13408.
[2] Moutik, B., Summerscales, J., Graham-Jones, J. & Pemberton, R. 2024. Quality assessment of life cycle inventory data for fibre-reinforced polymer composite materials. Sustainable Production and Consumption, 49, 474-491.
[3] Summerscales, J. 2025. Composites Design and Manufacture, Embodied energy, https://ecm-academics.plymouth.ac.uk/jsummerscales/MATS347/MATS347A9%20NFETE.htm#energy.
[4] Moutik, B., Summerscales, J., Graham-Jones, J., Pemberton, R. 2024. Quality assessment of life cycle inventory data for fibre-reinforced polymer composite materials, SAMPE Europe Conference, SAMPE, Belfast (NI), 24-26 September 2024.