With Repro-light for sustainable lighting

TRILUX participates in international sustainability research

TRILUX continuously pursues all options for action to optimise its portfolio with regard to efficiency and sustainability. To this end, the company relies on proven measures such as increasing energy efficiency, extending service life by means of highly developed thermal management or recycling after the use phase. At the same time, TRILUX is also on the lookout for completely new technologies, methods and business models that promote climate and resource protection. In this context, the company actively participates in the European research project Repro-light.

Repro-light (re-usable and re-configurable parts for sustainable LED-based lighting systems) aims to accompany the European lighting industry on its way to a more sustainable and competitive future. The research project is looking for ways and means to design a modular architecture and an intelligent production scheme for LED luminaires and to make lighting technology fit for the circular economy.

There are many metrics to sustainability assessment

Extensive analyses are indispensable when it comes to evaluating the relevance of replaceability, further use and recycling of the components of an LED luminaire and the influence of individual phases of the life cycle with regard to climate and resource protection. As a typical product, Repro-light therefore examined an LED luminaire from TRILUX and applied a variety of different metrics for sustainability assessment. In addition to

CO2 balance, abiotic depletion potential (ADP), acidification potential and eutrophication (accumulation of nutrients in water bodies) were also examined.

Different evaluation framework, new questions on sustainability

A look at the CO2 emissions delivered a familiar result: the energy consumed in operating the luminaire accounts for over 90% of total greenhouse gas emissions over all life cycle phases.

Essential factors for sustainability

Characterisation Factor Unit Environmental Relevance
Global Warming Potential
kg CO2 equivalent Increased positive radiative forcing due to the increase of greenhouse gases at the atmosphere
Primary Energy Demand
Megajoule Increased energy consumption from renewable and non-renewable energy sources
ADP elements
Abiotic Depletion Potential, Elements
kg Sb-equivalent Increased extraction of resources leading to depletion of mineral reserves
ADP fossil
Abiotic Depletion Potential, Fossil
Megajoule Increased extraction of resources leading to depletion of fossil reserves
Acidification Potential
kg SO2-equivalent Increased acidity of soil and water due to proton release from antropogenic emissions
Eutrophication Potential
kg PO4-equivalent Increased biomass formation and loss of biodiversity due to release of nutrients

Components from a sustainability perspective

However, a completely different picture emerged, for example, in the evaluation according to the Abiotic Depletion Potential (ADP elements). Here the influence on the environment is distributed quite differently: 77% are due to the production phase (including precious, limited materials such as gold and copper) and only 23% fall into the use phase (caused by the materials used to generate the energy needed to operate the luminaire). Another fact also becomes clear: at 75%, LED modules have by far the largest share of ADP of the entire luminaire. The remainder is divided between the LED driver (13%), the cabling (8%) and the optics and mechanical components (5% combined).

Luminaire ADP
5 optics 0 %
5 LED modules 75 %
LED control gear 13 %
wiring 8 %
mechanics 5 %

Example: E-Line LED

In view of this balance, surprising questions arise. For example, how sensible is the demand for replaceability of LED modules which is widespread in the industry? Replacing the LED module of a luminaire and continuing to use the housing sounds plausible only at first glance.

Outlook with interesting options

The TRILUX research department intensively engaged with the interpretation of life cycle analyses and put interesting scenarios for the most sustainable strategies for action up for discussion. The TRILUX luminaire examined was found to achieve maximum energy efficiency after 18,000 hours of operation when including the energy required to manufacture and operate the luminaire in the calculation. In contrast, optimum material efficiency according to the ADP estimate is achieved at 295,000 operating hours – an enormous discrepancy that calls for solutions.


What would things look like, for example, if an LED module or an LED luminaire were to be given a “second life” in the context of the circular economy? Lighting applications entail very different requirements. While one project may require 1,500 lm of luminous flux, 900 lm may be sufficient in another application. Therefore, if an LED module has exceeded the optimum in terms of sustainable operation in its first application, it could consequently provide exactly the right operating parameters for a second use with different requirements. Whether complete luminaires are dismantled and reused elsewhere or only LED modules are replaced remains open. In any case, in view of these considerations the reuse of luminaires and modules could become a new business model in the future that conceives of sustainability far beyond saving energy.

The Repro-light results also offer an interesting starting point for the optimisation of luminaires with regard to ecological criteria. TRILUX has achieved great success here, for example with the “E-Line Next” continuous line luminaire. The current version of the luminaire is more than 61% better for the environment than the previous version in terms of abiotic depletion potential. This was achieved by largely avoiding the use of particularly valuable materials, especially in the area of the LED module.

Conditions for reuse are already in place

Even if these ideas derived from the results of the Repro-light project are not yet practised today, they allow for a core statement: circular economy in the lighting industry is not only possible, it offers enormous sustainability potential. TRILUX has already created initial prerequisites for exploiting these opportunities for climate and resource protection. For example, the company already takes back luminaires from customers after disassembly.

In addition, newer business models such as the TRILUX Pay per Use programme turn luminaires into objects of rental or leasing contracts. They therefore remain the property of the manufacturer. Essential legal requirements for further use, new configuration or conversion are thus fulfilled. The consistent implementation of the principles of the circular economy will certainly bring about many new business models for the lighting industry. One thing is for sure: TRILUX will approach these new possibilities with an open and well informed mind.