Everlight's SL-Dolphin LED Street Lights to Illuminate Prague Streets

Everlight Electronics Co. Ltd. (TSE:2393) announced today that the company’s LED-based SL-Dolphin street light will illuminate two streets in the Czech capital Prague within the scope of a pilot project that tests various street lights based on LED technology.

The test series, carried out by Eltodo, the Czech lighting designer and nationwide electric installation service company, in cooperation with the city administration of Prague, aims at gathering experience with and accurate information on seven LED street lights of six different suppliers. The pilot project is initially running for four months.

All seven street lights have been installed in topographically different environments and hence are fulfilling different tasks ranging from lighting park walkways and bicycle paths to bright shopping streets or rather dark residential avenues. The selected streets and tracks are all located close to the city centre in frequently visited tourist areas. The street lights will remain in operation for the foreseeable future.

The installation phase

Everlight (via distributor MSC-Vertriebs-CZ s.r.o.) is the only project participant to which two streets have been assigned. Both are located in residential areas characterised by only few additional light sources such as a bright shop window light. Another reason why Everlight streetlights can be called ‘high performance’ is because the required pole heights amount to ten metres – the highest of all project installations. To play in this league is only possible with very bright lights and the result of previous analysis was that Everlight’s 120 W and 90 W SL-Dolphin Phoenix street lights proved best in series for these conditions. Another demanding condition was that the five street light poles were installed on only one side of the road with 35 to 40 metres between each pole, which was the longest pole distance throughout the pilot project.

In spite of these obstacles, the SL-Dolphin achieved outstanding lighting values in the first evaluation round that even exceeded the lighting levels of previously installed traditional street lights. In contrast to other solutions, the SL-Dolphin not only provided uniform illumination across the entire street width, but also illuminated the opposite sidewalk according to current standards.

                                   Dolphin – version 120 Watts              Dolphin – version 90 Watts

Colour temperature      5000 Kelvin                                          5000 Kelvin

Accomplished required 0.5 cd/m2                                             0.5 cd/m2
light desity                                              

Illuminance                    66 lx                                                     69 lx

The practical phase

At the opening ceremony on November 11, 2009, the city's residents were invited to join representatives of local political bodies, business industries and press members to enjoy music performances and a raffle. The residents also had an opportunity to voice their first impressions of the street lights in distributed evaluation sheets. Posters informed the audience on the actual measured initial values of the respective LED street lights and compared them to those of the formerly installed conventional lights.

In the ongoing four-month field trial, the people of Prague are encouraged to provide feedback on their experiences with the new technology, particularly with how they perceive the difference between LED lighting and traditional lighting. For example, amongst other things, the traditional colour temperature of 2,000 Kelvin rises to 4,000-6,000 Kelvin, which means a change from a highly yellowish light to a neutral white.