Gas, sodium vapor or LED: a conversion is always worthwhile.

When Sabine, the technical director of a municipal maintenance department, opens the annual inventory list of street lighting, it feels like a time travel report: In the historical quarter, there are still a few gas lamps. On the bypass road, high-pressure sodium vapor lamps work – reliable, but energy-hungry. And in several new residential areas, LED lights are already hanging, which are technically "modern", but still run rigidly according to a timer at night.

Sabine's challenge is typical: The city should save money, become more sustainable, and still ensure high safety in public spaces. A complete exchange of all poles and lights would be ideal – but financially and organizationally hardly feasible. This is where the retrofit idea comes into play: Continue to use existing infrastructure, modernize where it has the greatest effect, and gradually grow into future-proof, interconnected lighting.

What types of street lighting still exist today?

In many cities, several generations stand side by side. This is not a disadvantage – as long as the modernization is planned wisely:

Gas lighting is often part of the cityscape and culturally valuable, but labor-intensive and inefficient in operation. Where gas is still used, a strategic decision often makes sense: preservation in representative places – and conversion at locations where energy efficiency and operational safety are a priority.

Sodium vapor (and other conventional discharge lamps) are still in use in many main streets and older residential areas. The leap to LED here is particularly effective: Just switching to LED significantly reduces energy consumption and improves controllability.

LED lights are now widespread – but "LED" alone does not mean "smart". Many LED systems run without adaptive dimming, without status data, and without central adjustment. Those who retrofit here often unlock a second efficiency step: less power during off-peak times, better control, and less maintenance effort.

When does retrofit make sense – and when does it not?

Retrofit is particularly worthwhile when the load-bearing structure (pole, foundation) and large parts of the installation are still in good condition. Instead of initiating large construction projects, modernization is targeted: light head, driver, control, and communication – depending on the initial situation.

A short practical checklist helps in the decision-making process:

• Is the pole mechanically sound and does it still have enough remaining lifespan?

• Can the light head be sensibly reused or is an LED conversion planned anyway?

• Is there a need for dimming, switching profiles, remote monitoring, and quick maintenance?

If several points are "yes", retrofit is usually the fastest way to measurable results – without throwing away the existing infrastructure.

The retrofit approach: Resource-saving modernization

The core of the retrofit idea is simple: preserve as much as possible, modernize as much as necessary. In practice, this often means: The lamp pole remains because it fits structurally. And even with existing LED lights, there are often options to prepare them for light management and networking – for instance, by selecting compatible components during planned maintenance cycles.

An important building block for future-proof retrofitting is cross-manufacturer interfaces. At ENVIOTECH, the EnvioLux Node is designed for lights with Zhaga Book 18. This interface makes it easier to retrofit intelligent functions without having to replace the entire light every time – provided the light supports the standard or is selected accordingly during an LED conversion.

Why retrofit remains exciting even with already retrofitted LEDs

Many municipalities have already completed the first step – LED. The second step is "optimizing operation": adaptive dimming profiles, demand-based lighting, transparency about energy consumption, and early detection of disturbances. This transforms a "bright" street into a controllable street – thus providing more safety and planning ability in everyday life.

And it doesn't just stop at light: connected lights can become part of smart infrastructure – as a platform that can be expanded with additional sensors as needed. A modular structure is important here: start today, expand tomorrow, without the city having to rebuild every time.

Conclusion: Modernize without demolition – that is the retrofit advantage

Whether gas, sodium vapor, or LED: In almost every initial situation, there is a retrofit path that brings costs, resources, and implementation speed into a good relationship. For Sabine, this means: modernize first where the effect is greatest – and ensure the lighting is set up so that it can grow along in the coming years.

More about retrofit and connected street lighting with ENVIOTECH