We recently came across an interesting article on Lux Review as to why a return to replaceable light modules may not provide the results the community are seeking when it comes to sustainable lighting.
The idea of developing luminaires with parts that are easily removable for repair and maintenance would seem a “no brainer” and has become a popular suggestion as a way forward, and the lighting industry looks towards achieving more of a circular economy. The above article outlines why this stops making sense however when you look more deeply at details such as embodied carbon and the use of rare-earth metals within the LED modules.
We are yet to see if lighting manufacturers do proceed along this track but it certainly appears that more research is necessary to ensure this is not a misstep that causes issues of its own.
In the meantime, the best attempts at sustainability are making sure the correct type of luminaires are chosen for the right reasons. Not the cheapest option for immediate cost savings, but ones that will be long-lasting, and can cope with changes that may be required to accommodate changing workspaces.
Lifeframes for LED luminaires can be extended by taking into account that as LEDs degrade over their lifetime, their luminous flux decreases. Lighting design should take into account the life cycle of the luminaire and allow for such decreases. The problem with this is it oftentimes means “over illuminating” the area at the beginning of the luminaire’s life, in order to achieve optimal light output as the LEDs output starts to reduce.
A control system can be used to allow to reduce lumen output in the early stages of the luminaire’s life cycle, and gradually increase it as the LED output decreases over time. Additionally, dimming the light decreases the degradation, effectively increasing the life or the product.
With energy costs in New Zealand relatively low, and with much of it coming from relatively sustainable sources, energy savings have never been chased to the same degree as overseas. However if you consider that the energy savings achieved by evening out the LED output curve, dimming lights when natural light sources are available, and turning lighting off or down in unoccupied areas, will also considerably lengthen the life of the luminaire, thus reducing the environmental footprint . . . it starts to look as if (for the short term at least) the lighting control system will step up as the hero when it comes to sustainable lighting!