In some parts of Beijing, LED modules for street luminaires with an output of 120W or 180W now replace the conventional 250W or 400W sodium vapour lamps. As a result, these urban districts achieve energy savings in street lighting of up to 50%. For the metropolis of Beijing with its high energy consumption, this is of great importance. In addition to energy efficiency, light quality also played a major role in the decision for conversion. Dong Cheng, Chao Yang and Da Xing are urban districts bustling with life. For that reason, excellent illumination was required to increase safety for both drivers and pedestrians.
The city planners decided in favour of the powerful OSLON SSL LED by OSRAM Opto Semiconductors. They are part of the 1-W class; with their compact size of only 3 x 3 millimetres, they are currently the smallest LED in their class and luminous efficacy on the market. Even at higher flux rates, they work reliably and efficiently. Their good color rendering index with natural appearance of colors and clearly contoured rendition of contrasts provides additional safety on Beijing's streets.
OSLON SSL LED have a beam angle of 80 degrees and are thus ideally suited for street lighting; the ideal beam angle for this application is 120 x 80 degrees. In this way, the LEDs meet all of our technical requirements and we have no problems integrating them into the external lenses. The result is homogeneous and powerful illumination of the streets without liht pollution, explains Bing Hu, Managing Director of the HBTechnology CAST Group. The long lifespan of OSLON SSL LED also results in lower maintenance requirements, which might otherwise have obstructed the flow of traffic and generated additional costs.
Less is more
Especially thanks to their capability of handling high-current loads, OSLON SSL LEDs can be used to realize particularly energy- and cost-saving lighting solutions. At an operating current of 350 mA, this light source achieves a typical brightness of 110 lm in ultra-white (5700 and 6500 K). At an operating current of 350 mA and a color temperature of 3000 K it achieves a typical efficiency of 82 lm/W and a brightness of 92 lm. And brightness is an impressive 156 lm (warm white) at an operating current of 700 mA. This allows us to realize lighting applications requiring a lot of light by using fewer LEDs. If, as planned, Beijing converts all of its street lighting to LED, the savings potential is enormous, states Kai-chong Cheng, Marketing Director at OSRAM Opto Semiconductors in Asia.
China is the leading market in LED street lighting, representing approx. 50% of applications worldwide. The pilot project in the capital is to be followed by other cities.