Publications

Life cycle assessment (LCA) quantifies the whole-life environmental impacts of products and is essential for helping policymakers and manufacturers transition toward sustainable practices. However, typical LCA estimates future recycling benefits as if it happens today. For long-lived products such as lithium-ion batteries, this may be misleading since there is a considerable time gap between production and recycling. To explore this temporal mismatch problem, we apply future electricity scenarios from an integrated assessment model—IMAGE—using “premise” in Brightway2 to conduct a prospective LCA (pLCA) on the global warming potential of six battery chemistries and four recycling routes. We find that by 2050, electricity decarbonization under an RCP2.6 scenario mitigates production impacts by 57%, so to reach zero-carbon batteries it is important to decarbonize upstream heat, fuels, and direct emissions. For the best battery recycling case, data for 2020 gives a net recycling benefit of −22 kg CO2e kWh−1 which reduces the net impact of production and recycling from 71 to 49 kg CO2e kWh−1. However, for recycling in 2040 with decarbonized electricity, net recycling benefits would be nearly 75% lower (−6 kg CO2e kWh−1), giving a net impact of 65 kg CO2e kWh−1. This is because materials recycled in the future substitute lower-impact processes due to expected electricity decarbonization. Hence, more focus should be placed on mitigating production impacts today instead of relying on future recycling. These findings demonstrate the importance of pLCA in tackling problems such as temporal mismatch that are difficult to capture in typical LCA.

A pilot study run by the University of Bath in partnership with Bath & North East Somerset Council, Chapter2 Architects and the South West Net Zero Hub

In January 2023, Bath & North East Somerset Council (B&NES) implemented the first local planning policies in the UK requiring, first, that all new building developments achieve net zero operational energy, and second, that major developments meet an embodied carbon target. Both go far beyond the existing national building regulations, but they are representative of a growing number of similar policies from local authorities.

This paper describes a collaboration between B&NES and the University of Bath which explored the first months of the new policies’ implementation, to identify the impacts on building designs, the reception by practitioners, and opportunities for policy development and refinement. Thirty-eight eligible planning applications were analysed, the majority for minor residential buildings
eligible only for the operational energy policy. Despite a non-compliance rate of over 50% – primarily caused by a lack of policy awareness – many applications for buildings theoretically achieving net zero operational energy were received, representing efficiencies far beyond current standards. However, scrutiny and monitoring will be required for these ambitions to be met in practice. A
corresponding questionnaire was completed by 65% of applicants. Although the responses were largely negative, with particular concerns over cost and viability, there was broad support for the policies’ aims and an expectation of long-term emissions savings.

A long-term study is now needed to track the evolving industry response, quantify the real emission savings through construction and occupation, and further engage with stakeholders to support the policies’ implementation, development, and wider impact.