Secure and energy-efficient street lighting requires real-time control of luminaires


Street lighting could create significantly safer traffic conditions while saving significantly more energy than before. One principle should be that light must be secured at moments when we truly need it. In such cases, dimming of luminairesmight not be sufficient.

In fact, we should learn how to turn the lights on at full power exactly when the traffic takes place; and how to use as little light as possible at other times. The answer to this challenge lies in dynamic dimming, the third-generation street lighting control systems.

Diotech has developed dynamic dimming solutions for street lighting since 2014. In cooperation with Comlight, we have installed five pilot projects in Estonia.

To illustrate the potential of third-generation management systems, we will describe each pilot section and its initial results in more detail.


Pilot installation 1: Väike-Turu Street, Tartu

The installation began work in June 2015. A total of 14 LED luminaire (150W) are available with Comlight´s motion sensing street lighting system.

This is a good example of a street that borders on the main street passing through the city. The traffic load on this street is episodic: sometimes light is needed at any time. However, at night, there may be only a few road users on the street.

According to primary results, motion-based management has provided additional savings of 45% to 49% of energy costs (depending on the specific observed period). Also, thanks to movement-based control, street lighting is guaranteed at the time of traffic. At other times, the lights are in dimming mode (10% of rated power).


Pilot installation 2: Vahi roundabout, Tartumaa

The installation started work in July 2015. There are 4 LED luminaires (97W) with Comlight´s motion sensing street lighting system.

This is an example of an intersection on the main road of the country (Jõhvi-Tartu-Valga), but the traffic load is high only during the peak hours of the morning and evening. At night late at night, the traffic load is very low, allowing you to keep the lights in the dimming mode even up to 70% of the time.

The result is considerably lower energy costs combined with a secure light solution (roundabout gets illuminated only during active traffic).


Pilot installation 3: Are intersection, Pärnumaa

The installation started operating in September 2015. A total of 20 LED luminaires (97W) are available with Comlight´s motion sensing street lighting system.


As the section is located on the Tallinn-Pärnu Ikla highway, it is a high-traffic road section with a daily traffic load (about 7,000 vehicles a day). However, this is an excellent example of a section where, despite the high traffic load, the night load falls significantly lower. The result is a situation where more than a third of the time the luminaries are in the dimming mode.


Pilot installation 4: Sindi crossroads, Pärnumaa

The installation began work in September 2015. There are 15 light-emitting diodes (97W) with Comlight´s motion sensing street lighting system.

This is a section of the main road next to the settlement, with a daily traffic load of approximately 3000 vehicles. The traffic load is highest during the dark during the morning and evening rush hours. At other times, traffic is episodic.

This is illustrated by the initial results, as more than 40% of the time the lights are in the dimming mode. The result is a sustainable light solution that ensures safe traffic both to nearby SindI residents and to road transport.


Pilot installation 5: Suur-Sõjamäe tee, Tallinn

The installation began work at the end of October 2015. There are 32 LED luminaires (97W) with Comlight´s motion sensing street lighting system.

This is a good example of a system solution combining both the street leading from the city and the bus wagon, the pavement and pedestrian crossings.

Due to the luminaire based control, each luminaire can be set individually. At the moment, it is still quite a new installation, which is why it is still early to talk about the results.

All in all, as seen from the pilot projects listed above, third generation management systems can be successfully deployed on different roads and streets of different profiles. Diotech continues to actively develop street lighting systems based on dynamic dimming. If you have any questions about this topic, please feel free to contact us!


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