As part of the SUMATRA (SUstainable use of MATerials in future luminaire designs – from Recycling back to Application) project consortium, TRILUX dedicated over two years to researching ways to make LED lighting more sustainable. The project, funded by the German Federal Ministry for Economic Affairs and Climate Protection BMWK, participants such as the Fraunhofer Institute for Reliability and Microintegration IZM (life cycle assessment), Interzero (recycling) and Inventronics (LED systems). Each company brought its core competencies to the table. The consortium's final report highlights key aspects of sustainable luminaire development and identifies areas needing further research and action.

Life cycle assessment: analyzing the environmental impact of lighting

Humanity faces global challenges, including climate change, resource consumption and biodiversity loss. To understand the environmental impact of lighting, the SUMATRA project conducted life cycle assessments on various products and usage concepts. The evaluation considered several environmental impact categories. The influence of lighting on resource consumption was measured using the Abiotic Depletion Potential of the Elements (ADP). At the same time, the contribution to global warming was assessed with the Global Warming Potential (GWP). However, the impact of lighting on biodiversity cannot yet be quantified in life cycle assessments.

Results: key factors for sustainable lighting

The research identified critical starting points for developing sustainable lighting. Calculations of the GWP revealed that a luminaire generates approximately 1,000 kg of CO2 equivalents over its entire life cycle. Only 1-5% of these emissions occur during production; most are produced during usage. Therefore, improving luminaire efficiency and implementing effective lighting management are crucial for reducing CO2 emissions caused by energy consumption.

Some components of the Lumega IQ 70 model after the first recycling step

Electronic components, particularly the LED module and electronic ballast, have the most significant impact on ADP. Variations are notable: LEDs with bonding wire, for example, have an ADP around 500 times higher than flip-chip LEDs. Another approach to minimizing ADP is to save on ballasts, for instance, sharing ballasts among multiple luminaires or, in the case of linear lighting, using the longest possible luminaires per ballast. The recycling process was also thoroughly examined, which highlighted that the current recycling methodology primarily focuses on the reuse of metals, indicating substantial potential for optimization in other areas.

Some components of the Oleveon Fit after the first recycling step

 

The demonstrator: developing a sustainable prototype

A sustainable luminaire prototype was developed to demonstrate SUMATRA's findings. It reduces GWP by 15% and ADP by up to 30%, compared to a typical luminaire over its entire life cycle. Efficiency was a key focus for the prototype, and improvements were made without compromising quality and functionality. Greater efficiency gains were possible but would have been at the expense of light quality, which TRILUX, as a quality supplier, was unwilling to do. "We don't want to compromise lighting quality for the sake of efficiency," explains Dr. Sebastian Knoche, Lighting Technology Research Team Leader at TRILUX, who coordinated SUMATRA as project manager. "Sustainable lighting should be high quality and enjoyed by customers for a long time," says Knoche.

Future tasks - moving away from crude oil-based products

The comprehensive life cycle assessment showed that efficiency improvements have a more significant impact on the GWP of a luminaire than recycling plastic components like housings or optics. Nonetheless, plastic recycling remains an important building block for greater sustainability. "Our planet has a plastic problem; we produce far too much and recycle far too little," summarizes Sebastian Knoche. "That's why we must not only become independent of fossil fuels in energy production by 2050 but also eliminate crude oil-based products like plastic in material production," he explains. TRILUX demonstrates this with sustainable production concepts for luminaires like the Oleveon F and Aragon F, which feature housings and diffusers made from 100% recycled plastic.

Knowledge transfer: internal guidelines and external publication

To increase sustainability within the company, TRILUX has incorporated the SUMATRA findings into an internal guideline for sustainable luminaire design. Additionally, the consortium actively communicates the research findings to the industry, for example, in a scientific article in the LED Professional Review LpR (May/June 2024) that offers nine recommendations for the lighting industry and policymakers.