Energy optimization of LED systems for outdoor lighting management
Optimization of energy consumption in LED street lighting is more than LED chips with higher efficiency and intelligent management. There is a potential in optimizing and reducing the energy consumption with up to 20 % by improving the optical design of lenses for street lighting to match the exact context. It seems realistic to achieve these improvements and still deliver at a competitive price, especially when the cost is calculated over the lifetime of the LED system. The reason is new 3D printing technologies for optical components combined with new intelligent design software for optical systems.
When it comes to efficiency and performance LED is superior compared to conventional light sources. Unfortunately, there are still a lot of energy wasted in LED systems in form of stray light that never leaves the fixture or is directed in inappropriate directions. Most of all LED based street lighting systems are designed to be fitted with different standard lenses that remotely fit the specific context in which the fixture is included. The challenge is simply that these lenses are developed for an international market and to cover broad, why it is rarely possible to find an optimal lens for the specific task.
Stray light is a waste of energy, which is obviously a bad thing, but it's even worse when the light creates discomfort glare. In street lighting glare can cause serious risks that can and should be avoided.
DTU Fotonik, HeSa Light and Apiosoft will collaborate to optimize the optical system, and the design- and production process to enable commercialization of customized and optimized solutions for street lighting.
The project is based on a hi-performance fixtures from HESA Light installed in DOLL Living Lab. The DOLL Living Lab and Quality Lab facilities will be used to conduct on-site as well as lab measurements.
The goal is to achieve an overall reduction in energy on 20 % of the LED system, and to investigate opportunities to implement the solutions in commercial products.
The aim of the project was to show, in LED road lighting, how it is possible to optimize the design of the optical solution for the actual context, an how you both can achieve better light distribution and energy savings. And through analyzes, explain commercial perspectives in implementing mass customization of lenses. For a case with a specific road lighting luminaire, on a specific type of road stretch, using new CAD optimization software based on geometric 3D-ray tracing and CIE standards for road lighting, a new lens system was to be designed, optimized and developed.
The result of simulations of road lighting using the new optimized lens system shows, that it is possible to achieve improved light distribution through less waste light and better homogeneity and possible energy saving by adjusting the total flux of light. It is shown that there are too big design restrictions on 3D printing of optics and therefore that it is not a sustainable production method in this case and at this time. DTU Fotonik has simultaneously developed a coating process that is an affordable replacement for manual polishing or high precision milling of injection molding tools that could be a possible manufacturing method.
The major perspectives shown in the project for the use of custom-designed optical lenses, has DTU Fotonik used and demonstrated in a parallel project on stadium lighting. Here energy savings of 50% and 90% less waste light and better homogeneity was achieved compared to metal halide lighting.
