Joensuu switches to smart outdoor lighting

Error notifications are now received in real time

City lighting is successful when residents don’t pay any attention to it, Joensuu city engineer Tero Toivanen and developer manager Janne Kettunen say.

The city of Joensuu has 22,000 outdoor lights, and until now they have had one control system. According to Toivanen, the old system was more than ten years old and at the end of its mileage.

The switch to the intelligent outdoor lighting control system was completed in Joensuu at the end of 2023.

There are now around 300 street light centers around the city, and behind one center there are an average of 70 street lights.

Janne Kettunen ja Tero Toivanen Joensuun hallintotalolla
The city of Joensuu has 22,000 outdoor lights, which are now controlled via an intelligent system.

Error notification in real time

If there is an error in one of the centers, it will be notified immediately.

Toivanen says that even though the new lighting system in Joensuu is able to indicate quite precisely the point where the light does not light up or if it lights are on too long, there are tens of thousands of human sensors in the city that report this.

– A town resident called to say that the light has been off for a couple of days, isn’t there anyone going around and looking, Toivanen laughs.

– I answered him that we have 78,000 supervisors in the city. So the city does not have to use resources to monitor the street lights thanks to the awakened residents.

– Lighting is a surprisingly sensitive and interesting thing, adds Toivanen.

Now we can see directly from the system where the error is and define the location.

After the initial fine-tuning, the new system has already proven its effectiveness, according to Janne Kettunen.

– Now we can see directly from the system where the fault is and define the location.

Previously, you had to go through the system to see if something was wrong. In the old system, for example, there was no notification of disturbances in lighting centers, now it notifies the exact location.

The new lightning system saves Tero Toivanen (left) and Janne Kettunen’s time and possible errors are noticed faster than before.

The price of electricity sparks discussion

Tero Toivanen says that maintenance and monitoring of the city’s outdoor lighting is now possible remotely. Thanks to the new system, it would even be possible to control the lamps individually if necessary. And most importantly, energy efficiency improved even more.

– LEDs consume one third compared to traditional lights, Toivanen explains.

– However, the energy saving in renewing the lighting system is not as great as it was when switching to LED lights a good ten years ago.

In recent years, the price of electricity has sparked discussion among the people of Joensuu.

– When the electricity price increased rapidly, you noticed it in the amount of feedback from residents. If a light was on somewhere during the day, there was immediate feedback, Janne Kettunen says.

Thanks to modern light technology, the cost of seasonal lights, for example, is very low.

– We got a feedback about Christmas lights that it was a waste of electricity. The yearly expense of Christmas lighting is about 1,500 euros.

The city of Joensuu has been using energy-efficient LED lights for ten years.

Savings are calculated in time, not money

Surprisingly, the new lighting system does not bring much savings, because, according to Tero Toivanen, the city has already installed LEDs for ten years. But if time is money, the city will save a lot compared to before.

– Energy consumption started to drop significantly already ten years ago when switching to LEDs. Now 87 percent of all city lights are LEDs.

– The new lighting system has no effect on consumption, but we can control the lighting times and see the energy consumption.

Even so, the idea that street lights burning all night is a waste of money still lives on among some city dwellers.

According to Tero Toivanen, the benefit from lighting is greater than the money spent on it. At the time of the old light technology, even Joensuu used night extinguishing, when part of the urban environment was dark in the middle of the city.

– Lights are an important safety factor. Darkness is perceived as unsafe in the city.

In Joensuu, light can be seen not only in street lights but also as lighting of buildings and light art. The picture shows the Dancing Waters performance in Ilosaari in the fall of 2023.

The best lighting is unobtrusive

According to Toivanen and Kettunen, the best lighting in the city is the kind that the city dwellers don’t even notice.

– All new lights have a dimming profile and in quiet times the light output is reduced by half, the human eye doesn’t even notice it, Toivanen knows.

Even though LEDs consume a little electricity, even that little consumption is halved at night.

– And from the end of May to the end of July, all the lights are turned off at night, except for the city center.

Janne Kettunen says that the lights turn on and off according to the twilight sensors.

– The sensors study the brightness and darkness of the weather. They don’t react to fog, although if it’s dark enough, even to that.

According to Toivanen, different sensors and meters can also be installed in the new street lights.

–A lamp-specific air quality or noise meter could be possible in the future. It has not yet been seen necessary to install such, but technology would make it possible.

The article was produced as part of the activities of the City of Joensuu Innovation Ecosystem Agreement (ERDF), co-funded by the European Union and the city of Joensuu.

Artikkeli on tuotettu osana Joensuun kaupungin innovaatiotoiminnan ekosysteemisopimuksen (EAKR) toimintoja, joita osarahoittavat Euroopan unioni sekä Joensuun kaupunki.

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