Initial Situation
This article outlines how the e5 community of Böheimkirchen is comprehensively upgrading public lighting to LED systems with situational and demand-driven light control. The focus is on the planning and implementation of Smart Lighting Böheimkirchen.
About the city Böheimkirchen
The market town of Böheimkirchen, with approximately 5,100 residents, is located in the district of St. Pölten-Land in Lower Austria. The town is characterized by a lively town center with two main roads and several cadastral communities, some of which are a few minutes’ drive from the town center and are sparsely populated.
At first glance, it appears to be an average Austrian municipality. However, upon closer inspection, it represents a pioneering effort in Austria, at least in terms of street lighting. The municipal administration decided to use the transition to LED lighting as an opportunity to comprehensively digitize and convert the outdoor lighting to smart lighting.
Administration preparations for smart lighting
Due to the project’s scale and the pre-calculated total value, a public tender is required. To ensure a fair allocation of the project, the European Union’s rules and regulations for public procurement must be followed during the tender creation process. Once the tender text is finalized, it is typically not long before the first bids are received at the municipal office, particularly for a project of this size in Austria.
Project development and planning are handled by L.U.X. GmbH, led by Bernhard Gruber, DI(FH). Ultimately, AES Lichttechnik from Ottenschlag is selected and commissioned to carry out the upgrade of the public lighting and the digitalization of the system.
Financial support
Of course, no exact figures are mentioned here, but it can be assumed that the implementation of the project for the market town of Böheimkirchen cannot be financed from petty cash. External assistance was required, consisting of various grants from the Lower Austrian state administration, particularly the Energy and Environment Agency of Lower Austria.
The goal of the state of Lower Austria is to have completely converted street lighting to LED lighting by the end of 2030. To achieve this ambitious goal, the state is investing a substantial amount of money and supporting its municipalities and cities with well-funded grants that particularly focus on the digitization of lighting, including smart lighting solutions.
Coordinates of the light points
During execution, documenting the locations of the lights using GPS coordinates proved to be essential. This was crucial for keeping track of the progress of the retrofit and for saving time and resources when locating the installed controllers and sensors. Fortunately, this documentation was available and could be adapted in an Excel spreadsheet so that the light points could be easily transferred into the “slcontrol” software.
Consultancy and idea generation
The comprehensive retrofitting of street lighting presents a wide range of tasks for any administrative unit. After all, this is an activity that should only occur every 20 to 25 years and requires immense planning effort.
Essential to this process is knowledge of the current state of technology and a forward-looking perspective. The responsibilities of the person in charge from the public works department extend far beyond street lighting, making it impossible to stay up-to-date in every area. This is where independent consultants come in. In this case, Bernhard Gruber, DI(FH) from L.U.X. GmbH, accompanied the municipality from the beginning to the completion of the system. The municipality received advice from him on both standard-compliant light profiles and on funding and the digitization of the lighting system, including smart lighting solutions.
Smart Lightings technical components
Since a prerequisite for receiving state funding is the digitization of street lighting, the municipality is advised to equip the technical streetlights with Zhaga interfaces on both the top and bottom of the luminaire head.
Why are both Zhaga interfaces used?
- Allows for the subsequent integration of additional sensors
- Facilitates an easier transition to other systems
All calculations for light profiles and standard-compliant lighting are carried out by the aforementioned lighting planner. Luminaires from the manufacturer Vizulo are used. To digitize the lights and ensure situational lighting, the following products are used:
- Wireless controller with integrated eSIM: SLC Hub 203-C EU from esave AG
- Wireless controller: SLC Hub 203 EU from esave AG
- lix.one SLC radar sensors
The SLC Hubs 203-C EU serve as gateways. Configuration is carried out via the slcontrol web app.
Timeline
There is a nine-month gap between the publication of the tender and the detailed planning of the lighting control system. By November 2023, the retrofit of the luminaires was largely completed, and the installation of controllers and sensors began afterward.
The officials of the municipality of Böheimkirchen have a clear desire to test the system before its rollout across the entire municipal area and cadastral communities. Both personal observations and public feedback are crucial. The test areas include two residential zones, an industrial area, a major traffic artery, and a heavily frequented street within the municipality.
Since all luminaires are equipped with two Zhaga interfaces, the deployment of controllers and sensors is flexible. It is important to observe the specified ratio of 2:1 for controllers to sensors in the planning process.
The testing phase begins before Christmas and lasts initially for four weeks. The assignment of sensors and controllers to the light points is carried out by Andreas Schnegg-Primus in close coordination with the lighting design planning office.
Smart Lighting Configuration
The dimming profiles are calculated based on the standards O1055 & 13201-2 in close coordination with lixtec. For the two residential areas and the industrial zone, the lighting class M3 is assumed. For this lighting class, a reduction to a minimum lighting level is permitted. This level must not fall below 50% of the lowest level of the lighting class.
For M3, this results in a base lighting level of 15%, with full illumination triggered by motion detection. The hold time for the lighting is set to 60 seconds at the start of the pilot phase.
For M3, this results in a base lighting level of 15%, with full illumination activated by motion detection. The lighting hold time is set to 60 seconds at the start of the pilot phase.
For the other two test areas, the project team opts for dimming based on weighted hourly traffic volume. In summary, this means: The sensor counts the traffic and extrapolates the volume to an hourly rate.
For this variant, the standards also specify values. If there are more than 300 vehicles per hour, no dimming occurs. For traffic between 100 and 299 vehicles per hour, dimming to 75% is allowed. For traffic between 40 and 99 vehicles per hour, dimming to 50% is permitted, and below 40 vehicles per hour, dimming to 30% of the nominal power is required.
Evaluation of the test phase
The observation period for the pilot installations was set from December 17, 2023, to January 22, 2024. During this time, the officials of the municipality of Böheimkirchen were tasked with checking the functionality of the system in the relevant areas themselves and also monitoring and recording feedback from the public.
Reports from local residents
Until the relevant construction meeting, no complaints were received from residents, which is considered a positive sign. This suggests that the measure neither affected the sense of safety nor caused disturbances with the adapted lighting. Continuous monitoring and follow-up are essential. If any complaints arise in the future, it is possible to adjust the dimming profiles of the luminaires at any time using the “slcontrol” software.
Process for Evaluating Smart Lighting Areas
To obtain a valid evaluation, the two implemented variants of demand-driven lighting control were assessed separately:
- Volume-Based Control on Main Roads: This approach adjusts the lighting based on traffic volume, optimizing illumination according to the number of vehicles.
- Motion-Based Control in Residential and Industrial Areas: This method adjusts the lighting based on detected movement, ensuring sufficient illumination in densely populated residential areas and the industrial zone.
The basis for this evaluation is the actual activation time of the luminaires, with data sourced from the drivers via the “slcontrol” software.
What distinguishes the two types of Smart Lighting lighting control
In motion-based control, the lighting is dimmed to a low level, and the light output is increased when an object is detected by the radar sensor. This approach is typically used on pedestrian and bike paths as well as in residential areas. A ratio of 1 sensor to at least 2 controllers is recommended. According to standards, a reduction of lighting to 15% is applied in the selected test areas.
In contrast, volume-based lighting control does not always result in full illumination upon every movement detection. The sensor, as described, measures traffic flow and adjusts the light level accordingly. This variant is recommended for main roads to prevent constant fluctuations in lighting levels. For motion-based lighting, detecting 24 objects with a hold time of 60 seconds results in full illumination for 24 minutes per hour. For volume-based control, 24 vehicles per hour lead to a consistent light level of 30%.
To establish a comparable basis for calculating the burn duration at maximum output and the associated energy consumption, the on and off times provided by the controllers and sensors are used. Due to changing weather conditions, the activation times can vary significantly between two consecutive days. Data is sourced from the “slcontrol” software, which reads directly from the drivers and generates evaluations.
The following control units are used in the testing phase:
- 30 lix.one SLC
- 78 SLC-Hub 203 EU
- 5 SLC-Hub 203-C EU
In the test areas with motion-based lighting, significantly more sensors are deployed compared to those with volume-based lighting.
Evaluation of motion-dependent lighting control
In the residential areas of Gemersdorf and Mauterheim, the evaluation of the test period shows a reduction of 48% in energy consumption compared to uncontrolled LED lighting. In the industrial zone, a savings of 53% compared to uncontrolled LED lighting is achievable.
Interpreting the results
In the industrial zone, the difference between times of operation and non-operation is clearly noticeable, making the measure appear particularly effective. A detailed analysis even reveals differences between parallel streets, suggesting varying shift operations or delivery activities in specific areas.
In contrast, the situation in the two residential areas is the reverse of that in the industrial zone. During weekend nights, there is a higher frequency of light activation. The data also indicates which traffic routes residents use to access their homes, providing insights into local movement patterns.
Adaptation proposals
To achieve greater savings, it would be advisable to reduce the lighting hold time from 60 seconds. It is crucial, however, to balance energy savings with safety considerations.
In the residential areas, the close interconnection of control units means that reducing this hold time would also lead to fewer activations of neighboring lights.
In the industrial zone, it might also be beneficial to decrease the sensitivity of the sensors, assuming that there are no pedestrians during night and evening hours and that the sensors should only react to cars and trucks.
Evaluation of volume-based lighting control
In the Market Street area (both upper and lower sections), an energy savings of nearly 33% can be achieved. However, it is important to note that the lowest dimming level is set at 30%, meaning the maximum achievable savings is 70%.
In the Neustiftgasse area, energy savings of approximately 47% are realized.
Interpreting the results
While the installation in Market Street is proceeding as planned and the dimming based on traffic flow is functioning smoothly, there is a strong suspicion that motion-based lighting would be a better fit for Neustiftgasse. Since the radar sensor’s motion counter records fewer than 20 objects per hour on some nights, it may be more effective to adjust the lighting based on movement rather than traffic volume. This would allow the dimming level to be lowered further to 15%.
Adaptation proposals
Bernhard Gruber’s insight is to reconfigure one radar sensor in Neustiftgasse for motion-based lighting while keeping the second sensor on the volume-based setting. Energy statistics will be compared and evaluated after three weeks. In this case, smart lighting means providing statistics to the project team to assess the system’s condition.
If the suspicion proves correct, the next step would be to replace some hubs with radar sensors.
Implementation
This proposal is accepted by the project team during a construction meeting, and the configuration of the relevant radar sensor will be adjusted via the “slcontrol” software.
Roll-out of Smart Lighting components
Following the insightful testing phase, the focus shifts to the comprehensive deployment of smart lighting hardware, including lix.one SLC radar sensors and SLC-Hub 203 and SLC-Hub 203-C lighting controllers. It is essential to maintain the specified ratio of 2 hubs to 1 sensor across the entire area.
The deployment process is as follows:
Plan Provision and Adaptation:
- AES provides the adapted plans and updated lighting point layouts to lixtec. Adjustments were necessary due to the increased density of lighting points in some cadastral communities. This adjustment was based on changes in settlement expansion, as calculated by L.U.X. GmbH.
Sensor and Controller Allocation:
- lixtec is responsible for planning the arrangement of which lighting points will be equipped with sensors or controllers.
Implementation:
- Motion-Based Lighting: A comprehensive deployment of motion-based lighting ensures complete coverage of traffic areas. This approach will be applied throughout most of the deployment area.
- Volume-Based Lighting: An exception is the section from the highway exit to the town center (L110), extending south to Plosdorf, where volume-based lighting control will be used.
This deployment strategy aims to optimize smart lighting infrastructure, enhancing energy efficiency and ensuring effective coverage across all designated areas.
Process
Following the planning phase, installation is carried out by multiple teams from AES. The QR code on the underside of each product is scanned using a mobile phone and assigned to the correct lighting point number. This process minimizes the risk of errors and eliminates the need for the technician to manually enter numbers in the field. However, the technician still requires several minutes to move the lift into position and continue with the installation.
Ideally, each module should be pre-installed with the light fixture to avoid the need for additional trips with the lift and personnel. This would streamline the process and enhance overall efficiency.
Next Steps
The hardware is gradually distributed across the lighting fixtures, and simultaneously, configuration and neighbor assignments begin. Insights gained from the test areas are integrated into the deployment of configurations. This process is managed from the lixtec headquarters using slcontrol software from esave.
Before this can occur, the lighting points must first be activated in the software. To enable online configuration of the lighting points, SLC-Hub 203-C units are required. These act as “gateways” and are capable of bringing up to 120 devices online without a SIM card.
Special topic Christmas lighting
During the installation of the smart lighting test areas, an issue that had previously been overlooked emerged. Traditionally in Austria, city centers are adorned with Christmas lights. However, it is not ideal for the Christmas lights to outshine the street lighting itself. Therefore, a solution was required to enable dimming or turning off of the special holiday lighting.
The SLC Hub 203 and SLC Hub 203-C provide the capability to control up to four channels simultaneously via DALI. This means that the same device can manage both regular street lighting and special lighting, such as Christmas decorations. To achieve this, a component that converts the DALI signal to the signal used for Christmas lighting needs to be installed in the fixture head. In this case, Vizulo, the lighting supplier, will handle this installation.
This integration allows for the traditional Christmas lights to be turned off or dimmed during nighttime hours, just like the street lighting, ensuring a consistent and effective lighting strategy throughout the year.