Historical street light armatures now light up Leipzig with LEDs

In the German city of Leipzig, 360 historical Schinkel gas lamps in the city centre were fitted with LED lighting. In this way it was possible to preserve the traditional character of the lamps while making important energy savings.

Around the city’s famous St. Thomas Church, 360 typical 19th century streetlights, known for their characteristic warm light, were adapted and fitted with LED lighting systems without changing the appearance of the lamps or the quality of the light. The reconstruction of the historical lamps is part of a major project to install intelligent lighting in the city. 

Heritage on the outside, LED on the inside

The system that was used to modify these historical lighting fixtures was specially designed by Braun Lighting Solutions for the purpose, which made it possible to adapt the existing infrastructure easily. 

The four gas mantles that were originally in the lamps were replaced by four LEDs covered with tinted glass that mimicked the size and arrangement of the gas mantles. The result gives the impression of the original incandescent mantles hanging in the lamps. The difference can only be seen close up. A 1.2 Watt LED in the roof of the lamp lets a subtle light shine through the satin glass on the top of the unit. The LEDs can be turned on and off in turn and even dimmed if necessary. The design of the LED system in the armature guarantees the heat dissipation needed by the LEDs. 

The result

Thanks to these modified lamps, the city of Leipzig can save 20,000 Euro in energy costs every year. The LED lamps use only 22 Watts each, compared with 85 Watts for the lamps they replaced. This leads to a lower energy consumption of 89,369 kWh a year, which is a reduction of at least 73.3% and a 60.8 tonne annual reduction in CO2 emissions. In addition, the life expectancy of the LED system exceeds 90,000 hours, which creates additional savings for the city. 

Besides the huge savings and the environmental benefit, the changes have altered nothing about the appearance or lighting of this historic city scene. The residents are also positive about the result. 

Savings before, during and after use

As a partner in the cycLED consortium, Braun Lighting Solutions has put eco-innovation into practice in both its technological and non-technological aspects. Because the control units, LED modules and LED drivers have a common source, there is only one contact for implementation and later maintenance, which makes collaboration between city and manufacturer more efficient.

Braun Lighting Solutions (BRAUN) has modified its product development, the production of LED products and the EndofLife product collection in the interests of recycling rare earth metals. Some LED components naturally contain small amounts of these materials. To increase the yield of rare earth metals in the recycling process, it is imperative that all the components that contain them can be separated from the rest. For this reason, the manufacturer collects the modules at the end of their life cycle.

Braun also developed an easier separation process for the parts that contain rare earth metals. This required changing the thermal bridge between the LED-PCB and the heat sink. The manufacturer no longer uses thermal adhesive to attach the LED-PCBs to the heat sink. This makes it easier and cheaper to separate the relevant parts and allows the heat sinks to be re-used in new armature modules. This change reduces both the cost and the burden on the environment. Every reused heat sink reduces the energy consumption in the aluminium production process. Less aluminium consumption also reduces environmental pollution and lowers the cost of the material and the product. 

The author of this text is Nicky Constabel of Braun Lighting Solutions, who will contribute to the presentation ‘Eco-innovation process at Braun and Riva’ during the workshop ‘How to truly eco-innovate in the lighting industry?’ on 11 February.