Helsinki

Helsinki Energy tendered the City of Helsinki's outdoor lighting control system in 2013, and the C2 SmartLight control solution delivered by ISS Palvelut Oy was selected. Juhani Sandström, Lighting Manager of the City of Helsinki, says that the acquisition of the control solution was started due to energy savings and its main goal was to avoid unnecessary lighting. "The old system did not allow anything other than the on/off-control with half of the city-precision." says Sandström.

Objective: 20-25% energy saving

When launching the renovation project of the control solution, the city set an energy saving target of 20–25%. The City of Helsinki does not introduce total lighting night shutdown in different areas, but the lights on and off are scheduled according to the needs of each area:

• The brightness of the LED lights is adjusted according to the light needs. The brightness is measured from a few places on the street and the intensity of the lighting of the whole street is adjusted according to the measurements.
• The weather and season are taken into account so that the street always has optimal conditions. Twilight switches, for example, are used as an aid.
• The lighting can also be adjusted according to the amount of traffic.
• The lights can be controlled regionally. For example, the lights can be turned off during street events, such as along the route of the Via Crusis crusade play, without anyone having to go to the scene. This saves unnecessary labor costs.
• Unnecessary lighting of special areas, such as playgrounds, hobbies, parks and dog parks, is avoided, for example, by adjustable lighting according to motion detection.

Helsinki is entering the LED era

The City of Helsinki owns more than 86,000 outdoor luminaires. The most common type of lamp is still high pressure sodium, which accounts for almost 60% of lamps. There are about 25% of mercury lamps. The exit of mercury lamps from the EU market in 2015 has accelerated the replacement of luminaires in recent years, and in the future Helsinki will use dimmable LED outdoor luminaires in all new installations. LED luminaires are long-lasting, use significantly less energy than other luminaire types, and their light color is naturally pure.

Cost savings on maintenance

The control solution brings cost savings to maintenance, as the automation of fault alarms speeds up maintenance procedures. Another significant improvement is that the number of luminaire variations with different wattages was reduced. Thanks to wireless luminaire-specific control, the city can use, for example, two luminaires of different power classes from the same luminaire manufacturer, which can always be adjusted according to the lighting needs of the application. Maintenance and logistics are facilitated when separate 30W, 40W and 60W LED luminaires are not required, but all power classes can be covered by adjusting the 60W luminaire according to the needs of the respective location.

Technical implementation of the control solution

The control solution of the City of Helsinki consists of an information system and field equipment. The servers are maintained by ISS and placed as part of Helsinki Electricity's internal network. There is no access to the management environment from the outside. Also, all communications are encrypted all the way from the user interface to a single luminaire-specific controller. Data transmission in the telecommunications operator's network is closed to outsiders and it is not possible to contact the subscriptions in the street lighting centers from telecommunications subscriptions other than those used by the customer.

Street lighting centers have central control devices that switch the lighting network electricity on and off. Luminaire-specific terminals can be installed inside luminaires or luminaire poles, which enable the lighting to be adjusted according to the target. Separate wireless terminals are available for the desired special areas, such as playgrounds or hobbies, which enable separate control of the power supply of the area's lighting. “Special attention has been paid to the safe use and protection of the system at the customer's request. Helen trusts the supplier it has chosen, ”says Kari Rantanen, Service Director of ISS Palvelut Oy.

Photo (Valo magazine 1/2014): The twilight control settings, regional energy saving parameters and even the amount of luminous flux produced by a single luminaire can be set from the energy management control room according to the season. All communication of the control solution is completely wireless and does not require new cabling. Due to wireless data transmission, special attention has been paid to the data security and protection of the system, and for example all communications are encrypted all the way to a single luminaire.

The text is based on the article published in Valo magazine 1/2014.

City of Helsinki outdoor lighting control solution
Content: Renewal of the control system for street lighting
Goal: Saving energy and customizing lighting
Schedule: 2013-2014
Street light centers: 1700
Luminaires under control: 86 000