Smart city begins with smart street lighting

A Lantern, Three Nights

It is shortly after 10 PM. The city is getting quieter, but it is not sleeping: A last bus rolls in, a cyclist turns onto their way home, somewhere someone walks through a front door. And above it all stands a familiar sight: streetlights, bright and omnipresent. Yet we do not always need the latter everywhere, but still, it is more often missed than it should be.

This "constant light" was for decades the simplest answer to a complex question: How do we create safety, orientation, and quality of life in public spaces? Today, in the era of climate targets, tight budgets, and digital expectations, the simple answer is no longer sufficient. This is precisely where the topic Smart City begins – and it surprisingly often starts in a place that every municipality already possesses: intelligent street lighting.

The need is enormous: inefficient switching times, lack of transparency regarding defects, and high energy costs. Across the EU, orders of magnitude of 25,000–30,000 GWh per year are discussed for street lighting and its losses – energy that can be significantly reduced through modern control systems and retrofitting. Depending on the scaling, a potential of up to 1 million tons of CO₂ in annual savings is also mentioned in this context.

At the same time, cities are looking for solutions that work quickly, are affordable, and fit into the reality of procurement, operation, and data protection. A pragmatic approach is retrofitting street lighting – that is, making existing lights smart step by step, instead of completely overhauling entire streets.

Why Smart City is Advancing Slowly Despite Necessity

The vision is already here: sensors, data platforms, adaptive systems, digital control. In practice, however, Smart City often fails not due to will, but due to friction. Municipalities work with established infrastructures, long investment cycles, and complex responsibilities. Additionally, there are tendering processes, interface issues, and the concern about committing to specific technologies.

A second hindrance is safety – not only in road traffic but also in IT. Municipal IoT projects must today consider cybersecurity risks, data protection, and organizational resilience. This is rightly so, but it takes time and rarely allows for "just getting started". Especially for this reason, entry points that are manageable, provide clear benefits, and can be rolled out in a controlled manner work best.

Streetlights: The Underestimated Backbone of the Smart City

Why light in particular? Because streetlights are already positioned where Smart City should work: widespread, neighborhood by neighborhood, at intersections, school routes, bike paths, and squares. This geographical distribution is a strategic advantage. Whoever thinks about Smart City street lighting correctly not only builds energy efficiency – they simultaneously create a connected infrastructure that can later support other applications.

Many solutions on the market describe connected lighting as the "foundation" for further sensors and urban services. The difference lies in the path to get there. The less deep construction, replacement, and complexity are needed at the beginning, the faster "vision" turns into rollout.

From "On/Off" to Adaptive, Energy-Saving Lighting

Back to our lantern. Around 11 PM, it gets quieter. Modern systems for smart street lighting then do not dim indiscriminately but according to need: They consider time, ambient brightness, weather – and, most importantly, movement. When a pedestrian or a vehicle approaches, the light increases in the relevant zone; if the road is empty, it dims again. The result: safety remains, energy consumption and unnecessary light emissions decrease.

For municipalities, it is crucial that the control is not only local but also digitally traceable: Which light is working how? Where are there failures? Which profiles work in which neighborhood? An example of this retrofit approach is ENVIOTECH: with IoT-based retrofit kits, digital monitoring, and the ability to centrally control and gradually optimize light profiles.

Sensors on the Lantern: From Movement Impulse to Data Basis

A streetlamp is not just a switch but potentially a measurement point. Depending on the level of expansion, in addition to detecting movement and brightness, environmental data can also be integrated – for instance, temperature or air quality. A clear prioritization is important: First, the basic function (safe, norm-compliant lighting) must improve. After that, it is worthwhile to strategically add sensors where they provide real value.

• Movement detection for adaptive brightness on paths and roads

• Ambient brightness for clean transitions at dusk, weather changes, and seasons

• Operational data for maintenance: identifying defects, making interventions planable

• Optional environmental sensors as building blocks for data-driven urban development

Less Light Pollution, More Biodiversity

Smart City is often talked about through apps and mobility. However, light is a direct environmental factor. Too much or incorrectly directed light exacerbates light pollution, disrupts ecosystems, and attracts insects – with measurable effects. Research and pilot projects show that better light management and adapted lighting can significantly reduce the attraction of insects. "Intelligent" here does not necessarily mean "brighter", but rather more precise: light where it is needed – and as little as possible where nature and night need peace.

There is also a benefit for people: less glare, better perception, and quieter nighttime imagery. And for municipalities, it means: climate protection and biodiversity are not treated as additional projects but as results of better basic infrastructure.

Retrofit Instead of Major Overhaul: Why "Starting Small" is Often Faster

Many Smart City programs fail due to the "all-or-nothing" mentality: first the new platform, then the new network, then the new hardware – and suddenly a million-euro project looms. Retrofit turns this order around. Instead of replacing entire lights or poles, existing systems are upgraded. This lowers investment barriers, reduces construction sites, and enables pilot neighborhoods where savings and acceptance can be measured cleanly.

This builds trust – internally within administration, externally among citizens – and Smart City becomes reality step by step. In many cases, the investment can therefore amortize significantly faster than with a complete replacement, as existing infrastructure is reused.

Conclusion: Smart City Does Not Have to Start Big

When our lantern gradually dims around 5 AM, it is not science fiction but good operational logic: less waste, the same or better safety, less light at the wrong moment – and an infrastructure that makes further Smart City applications possible.

Whoever talks about Smart City today should therefore ask a simple question: Which infrastructure already exists everywhere – and can be made intelligent with manageable effort? In street lighting, the answer is almost always: yes.