Circularity in focus with TM66

At Light2Perform, industry leaders debated TM66 and its transformative impact on sustainable lighting, as well as its influence on greener practices in the lighting sector

Kristina Allison (right) and Young Lighter Kate Turley

Creating a circular economy in the lighting industry was a key theme at Light2Perform, held at London ExCeL last month.

During a session on rethinking sustainability in lighting, panel members discussed the CIBSE guide TM66 Creating a circular economy in the lighting industry, and highlighted the emergence of the new functional unit value as a key metric for comparing lighting products’ embodied carbon.

Kristina Allison, associate at WSP and co-author of TM66 (and TM65.2 Embodied carbon in building services: lighting) highlighted the increasing adoption of TM66.

‘It’s already being used across all product ranges from a manufacturer’s point of view,’ she explained, adding that consultants are integrating it into specifications and asking manufacturers for specific metrics.

Simon Fisher, founder and director of F Mark, elaborated on TM66’s practical application, and focused on the emergence of the functional unit value as a game-changing metric.

The metric measures lighting products’ embodied carbon per thousand lumens of output at 35,000 hours of life. With these parameters, he said ‘you can fairly evaluate which product is better.’

Fisher emphasised how the metric helps stakeholders make informed decisions about sustainability.

‘The beauty of embodied carbon calculators is that it’s pure metrics,’
he said.

Chair Matt Waring, editor at [d]arc media, underlined the importance of standardised comparisons, noting that: ‘It’s harder to manipulate figures to make yourself look better when there’s a fixed point.’

Fisher agreed, explaining that ‘every material has a known coefficient for embodied carbon. When applied fairly, it’s an excellent method for comparing embodied carbon across products.’

Daniel Lister, Society of Light and Lighting (SLL) President, noted TM66’s growing traction in Europe and beyond. ‘European manufacturers are seeing it as a game-changer. It allows that apples-to-apples comparison, which wasn’t possible with previous metrics,’ he said. However, he acknowledged challenges in creating universal standards. ‘It’s idealistic to think we could have a global standard. Getting industries to agree on a unified metric is a massive step forward,’

Lister noted, adding that, while regional variations may persist, TM66 represents a crucial move towards harmonising sustainability practices.

Lister emphasised the growing importance of reuse and circularity, particularly in higher education, where institutions manage vast portfolios of lighting units. ‘In our offices at Arup, we have seen embodied carbon savings of more than 80% simply by refurbishing light fittings. It’s not as hard as people think.’

Allison agreed, but noted disparities in client awareness. ‘Not all clients know they need this yet. We’re still trying to influence specifications and push the conversation forward,’ she admitted. Nonetheless, she is optimistic, calling it ‘a high priority’ for her firm and emphasising the need for persistence.

The discussion concluded with a consensus that TM66, though not perfect, is a significant step towards better sustainability metrics. As Lister stated: ‘It may not be the end goal, but it’s an amazing step on the journey. Anything that helps the industry focus on embodied carbon and circularity is a benefit.’

Turley wins SLL Young Lighter award

Kate Turley, of Chroma Lighting, was named the 2024 SLL Young Lighter at Light2Perform. Her award-winning presentation, ‘A tailored dynamic lighting and sensing paradigm to support wellbeing for people living with dementia’, highlights her research on the intersecting fields of lighting, technology and health.

Turley, a PhD researcher collaborating with industrial and academic partners, was lauded for her innovative work. Her journey into lighting began during her BSc in geophysics, when she gained an interest in programming, computing and the Internet of Things (IoT).

Her two-year Knowledge Transfer Partnership with Chroma Lighting and Ulster University resulted in the creation of an integrated lighting and sensing device designed to enhance the wellbeing of dementia patients. This IoT framework opens up new possibilities for understanding how light impacts dementia care, which Turley continues to explore in her PhD, supported by an Industrial Fellowship from the Royal Commission for the Exhibition of 1851. 

Her contributions have garnered global recognition, with publications presented at IEEE and INSTICC conferences, and accolades such as Best PhD Project, Best Interdisciplinary Research, and the Emerging Scholar Award between 2021 and 2024.’