The last of the 360 LED lights was commissioned at the end of August 2011. Braun Lighting Solutions implemented a multi-year development process in order to ensure that the LED lighting fixtures came as close as possible in colour temperature and appearance to the original lights. Future Lighting Solutions supported this process.
|Schinkel Street lit with LEDs|
The city's civil engineering department and Braun Lighting Solutions were tasked with integrating the LED technology in such a way that the historic appearance of the gas light was maintained. Accordingly, the original parts of the historic light were supplemented with a patent-pending technology that mimics the size and arrangement of the mantle. The four mantles are replaced by four LED modules covered by stained glass. This gives the impression of mantle lamps actually hanging in the lights. The difference between the LED lamps and the gas light originals can only be seen on close inspection. A single 1.2W LED in the roof of the lamp provides a subtle light for the opal glass at the top of the unit.
The system switching and control unit is a Maxidimm3000 developed by Braun with a 1-10V control interface and a 230V power connection, allowing various modes of operation for greater energy efficiency. The LEDs can be alternately switched on and off, and dimming functionality is provided, as well as the ability to choose between twilight and asymmetrical light distribution.
"In Leipzig, the LED technology of the future meets the past of city lights which are more than 150 years old," said Andre Braun, CEO of Braun Lighting Solutions e.K. "Our approach keeps the traditional form of the lamps but lets them shine in a new light through advanced LED technology. We have been able to deliver on the goals for energy efficiency and environmental protection at the same time as meeting the requirement to preserve a historical artefact."
|Lamp in the daylight|
The simulation of the first LED lighting concept was implemented at the Lighting Resource Center of Future Lighting Solutions. This original design was then gradually refined at Braun Lighting Solutions, which simulated the LED light distribution in an effort to match the historic gaslight original as closely as possible. Future Lighting Solutions also helped with the selection of electronic lighting components and connectors. Since the lights’ control units, LED modules and drivers come from a single source, there is only one contact in case of maintenance.
"Where there is light, there is also heat. The main achievement in the design is thermal management – dissipating heat from the LEDs. To help us meet the requirements, we gained valuable advice from Fraunhofer IZM Institute in Berlin. With this help we were well set to produce a successful design," adds Braun.
As the exclusive distributor of Luxeon Rebel LEDs, Future Lighting Solutions was responsible for ensuring consistency of light output at a colour temperature of 2700K across all the LEDs supplied in the production shipments to Braun Lighting Solutions.
"At Future Lighting Solutions, it is our mission to deliver such a limited LED colour gamut for just-in-time delivery, so that there is no perceptible colour difference across the manufactured units. The supply chain for the entire lighting system for the conversion of Leipzig's city lights was handled out of our Europe, Middle East and Africa Distribution Centre in Leipzig," said Alexander Müller, Head of Sales for Central Europe at Future Lighting Solutions.
The city of Leipzig participated in 2009 in a national competition for energy-efficient city lighting, sponsored by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, with its ‘intelligent city lighting’ entry. It finished third in the category for cities with more than 500,000 inhabitants. The funding it received was invested in the implementation of an extensive renovation project. "We are very pleased with the execution of this project. And the citizens of Leipzig have responded very positively to the improved night-time environment. This is confirmed by the numerous calls and emails we have received," said the city’s chief lighting planner, Rainer Barth.