Because it opens up so many options, LoRaWAN wireless technology is gaining ground. Stadtwerke Giessen started to set up a corresponding network in the city centre a year ago, which it will gradually expand over the coming months.
Giessen. Stadtwerke Gießen (SWG) has been involved in setting up and expanding a LoRaWAN - a Long Range Wide Area Network - for around a year now. This is a particularly efficient and at the same time low-radiation wireless data transmission system. And it is precisely this that opens up an extremely wide range of useful application options, especially for companies or municipal facilities. "We discovered LoRaWAN because, among other things, it allows us to read meter readings easily and cost-effectively," explains Matthias Hery, who is responsible for the project at SWG. In fact, knowing the current meter readings is not only useful for billing purposes. "Anyone who operates an energy management system also benefits from the possibilities that LoRaWAN offers in this area," says Matthias Hery.
Good coverage in the city centre
SWG's LoRaWAN currently has five so-called gateways at strategic points. This is enough to almost completely cover Giessen city centre with the useful service. The special antennas receive the data from the various sensors and forward it to the server at SWG. Here, this information is processed, visualised and issued to the users. In acute individual cases as a message or for more detailed observation and analysis in the form of a clear dashboard that can be easily read on a PC screen or smartphone. Example of monitoring a room: Are the windows and doors closed? What is the quality of the air in the room and what is the temperature? "All these parameters can be monitored with relatively simple sensors," adds Matthias Hery. If, for example, a window is still tilted open after a set time, the system sends a message to the caretaker. The issue of indoor air plays a major role, especially in times of pandemic. For example, if the sensor reports that theCO2 content in the air has reached a limit value, the dashboard sends an email requesting ventilation. "This special application is already being used in two schools in Giessen," says Matthias Hery. LoRaWAN is therefore helping to reduce the risk of infection in classrooms. Because the pathogens enter the room air via respiration, just likeCO2, the carbon dioxide content can be used to draw very precise conclusions about the potential viral load in the room air.
Keyword windows and doors: Unfortunately, break-ins and the associated vandalism have been on the rise recently. LoRaWAN cannot prevent this. But the technology does help to solve the offences. This is because the sensors not only document that a door or window has been opened, but also the exact time. And this is often a crucial clue for the police. Of course, an alarm could also be set up to report a break-in.
Expansion as required
Matthias Hery and his colleagues at SWG are currently planning to install an additional five gateways across Giessen. However, it has not yet been decided exactly where they will be positioned. "We will proceed according to demand when it comes to further expansion," explains Jens Schmidt, Commercial Director at SWG.
Each individual antenna can record and transmit data from around 10,000 sensors. The potential of the ten gateways planned for the final expansion is therefore enormous. This also applies to the sensors already available today. Checking the fill levels of tanks or waste containers, checking the soil moisture in planters and the areas of car park monitoring and management - all this and much more has been working reliably for years. LoRaWAN and GPS also complement each other perfectly. With the help of this combination, it is always possible to quickly determine where objects fitted with the corresponding transmitters are located - such as containers or valuable construction machinery. "We use LoRaWAN in conjunction with GPS in specially equipped buses to determine the reception performance of our gateways at different locations in the city centre," says Matthias Hery, describing an SWG use case. And LoRaWAN is even helpful in pest control: there are traps that report when they have caught a rat, for example. This is precisely where an important advantage of LoRaWAN technology becomes apparent - its efficiency means it can be used practically anywhere. "Almost all sensors work with a battery," says Matthias Hery, citing a key argument.
The fact that they work independently of the power grid also proves to be advantageous from another point of view: the sensors can be installed in places that are difficult to access - precisely where it is usually difficult to get to in order to check something, but where regular inspections are required. "We have now gained quite a lot of experience and can advise interested companies in detail," Matthias Hery continues. SWG may have to upgrade its network to enable these applications in difficult locations in particular. This is because the range of the transmitters decreases with the mass of building material between them and the gateway. "As long as we stay on the surface, we can easily manage 1.5 kilometres. But if a sensor is transmitting from a cellar or a shaft, we need much shorter distances," explains the expert. He adds: "We already have all of this on our radar during our initial discussions with interested parties."
For others too
Keyword experience: As a comparatively large regional energy service provider, SWG is in a position to set up a LoRaWAN and operate it reliably. Smaller municipal utilities cannot do this, as they usually lack the human resources to do so. However, because there are also companies in municipalities with fewer inhabitants that can benefit from the smart radio technology, those responsible at SWG have decided to market their expertise in LoRaWAN. In other words, as a service provider, SWG will take care of everything related to the pioneering wireless technology - from installing the necessary infrastructure and processing the data on its computers to providing a complete service for the client and its customers. "We expect this business area to develop very well in the medium term. More and more companies are recognising the potential of LoRaWAN," says Jens Schmidt, explaining the move. Experts are expecting high growth rates, particularly in the area of metering. Suppliers of district heating in particular will need remotely readable meters in future. This is the only way they can fulfil a new requirement at a reasonable cost: In extreme cases, they are obliged to transmit twelve meter readings per year. "This is not economically viable without remote reading," Jens Schmidt is convinced.
Companies in the water sector are also likely to be interested in the savings potential resulting from the transmission of meter data via LoRaWAN. Although they are unlikely to need monthly readings, they can still save a lot of money with this smart technology - simply because they no longer have to send anyone to the individual metering points. What's more, they receive much more accurate data. With remotely readable meters, they would no longer have to rely on meeting someone in person or hope that customers will read and transmit their meter readings themselves.
SWG has set up a publicly accessible dashboard to show interested parties how the data from the sensors is processed and visualised. It can be accessed at www.stadtwerke-giessen.de/dashboard. At www.stadt werke-giessen.de/lorawan you will also find lots of useful information on the topic and the relevant contact persons at SWG.