EMBODIED ENERGY | TM65.2 Eco Flex lights feature in a case study on the Grand Hyatt Kuwait hotel Shining a light on embodied energy Calculating embodied energy in lighting equipment can now be done more accurately thanks to the new CIBSE TM65.2 guide, which, say co-authors Kristina Allison and Irene Mazzei, is targeted at manufacturers and lighting designers to lower whole life carbon T he conversation around sustainability, embodied carbon and the circular economy has accelerated rapidly. Not long ago, it was commonplace for specifiers of lighting equipment to recommend luminaires with halogen or metal halide light sources, and fluorescent lamps were only banned from sale in the UK and Europe this year. The lighting industry is in a different, healthier place now, and has been leading the conversation on the circular economy with the release of two timely CIBSE guides: TM66: Creating a circular economy in the lighting industry, published in 2021, and TM65.2 Embodied carbon in building services: lighting, which came out last month. The original TM65 Embodied carbon in building services (aka the parent document) and accompanying carbon calculator is already a widely accepted methodology for calculating C02e in build services equipment. It does so without having to submit products for full Life Cycle Assessments (LCAs), a process that is lengthy and expensive. The TM65 methodology offers a route to evaluating and understanding the amount of 48 September 2023 www.cibsejournal.com embodied carbon within materials that make up products. It can even be used as a tool for development during the product design phase because of the processs fast turnaround. Lighting manufacturers have been very responsive to industry demands for this data and the 18 case studies within TM65.2 demonstrate this. The methodology enables material data, including manufacturing process data, to put a C02e value on lighting equipment. The more data that becomes available the more environmentally aware the decisions that lighting designers and specifiers can make for projects. Why a lighting version of TM65? Manufacturers of lighting equipment were so keen to calculate the embodied carbon in their products that they were using the parent