The Karlsruhe Institute of Technology (KIT) has developed novel and more economical LED street lights. Researchers have used a special set of weaker LEDs to replace traditional high-performance diodes, successfully reducing power consumption by 20%. As a result, carbon dioxide emissions are reduced and cities can save millions of electricity costs.
The local public utility company Pfalzwerke Netz AG installed a street lamp with a new lamp head for the first time in the city of Maxdorf (Rheinland Palatinate) in the Rhineland-Palatinate, Germany.
According to Michael Heidinger of the Light Technology Institute (LTI), they have significantly improved the efficiency and longevity of their luminaires compared to conventional LEDs. He designed an intelligent circuit to compensate for the aging and failure of individual LEDs. In the conventional scheme, since a single diode failure affects the entire system or a part thereof, it is difficult to connect a large number of LEDs in parallel, which is very common in Christmas light chains.
However, alternatives to series LEDs also have disadvantages because the required voltage increases as the number of LEDs used increases, while the legally permissible contact voltage is up to 120V, so currently only up to 40 LEDs can be connected in series.
But in the new design, a large number of LEDs can be installed on a single board (48 LEDs in a luminaire module) at a low cost. In addition, Heidinger's new switching concept can operate at 20V, and the safety is improved compared to the usual 120V.
New LEDs reduce power consumption and will benefit from cities in the future. Currently, LED technology has replaced traditional high-power lighting in many places. According to the public utility company in Karlsruhe, Karlsruhe is a medium-sized city with a population of 320,000 and requires about 55,000 lamps to provide lighting (of which 35% use LED technology). The total power consumption in 2018 is 10,800 MW. At the time, the electricity and maintenance costs incurred amounted to 3 million euros. At the same time, the extra reduction potential is also high.
Stefan Lang, head of technology and long letter at Pfalzwerke Public Utilities, said that if all street lights use new LEDs, the cost is expected to be reduced by up to 30%.
In addition, the new LED lamp has a luminous characteristic that is more comfortable for the human eye. The company's Gratz Luminance GmbH, based in Weinberg, Baden-Württemberg, Germany, produces the new outdoor luminaire. General manager Klaus Müller says the cost of low-power LEDs is lower than that of high-power LEDs. Therefore, even if the number of LEDs used is larger, the production cost and price of the new lamps are lower. At the same time, the technology for changing new luminaires is not complicated and the cost is not high. The company's lamp head can be directly applied to existing poles.
He also said that the city of Maxdorf will test the new streetlight, and other big cities are also interested in this technology.