Making brighter cities

Smart street lighting is driving smart city projects

Smart street lighting is driving smart city projects
Will Gibson on 13 February 2018
Picture of Will Gibson

Smart street lighting is driving smart city projects

As cities take advantage of LED conversion projects to add strategic streetlight connectivity, a new study indicates that many cities are not thinking long term when switching to LED.

According to analyst Northeast Group, 89 per cent of the world’s 363 million streetlights will have been converted to LED by 2027. This global phenomenon has helped to make centrally-controlled connected streetlights the first smart city application to be deployed at scale. The same report forecasts that by 2027 only 29 per cent of streetlights will be connected. Some of that gap can be attributed to differences in energy and labour costs between countries, which affect the short-term business case for adding connectivity.

But many cities could be missing on the strategic potential of connected streetlights. The idea of using streetlight networks as the vehicle for other smart city applications is already well established in some countries, enabling applications from air quality monitoring to connected waste bins. That’s not surprising because streetlights are an ideal base for sensors in many ways;

  • They efficiently map populations – where people congregate to live, work, play or travel, there is already an array of streetlights.
  • They provide a set of fixed data points – unlike crowd-sourced data from mobile apps, streetlight sensors give reliable reference point data.
  • They provide power to sensors – without batteries to worry about, even higher powered devices like video cameras can be installed to run unattended for many years.
  • They are safe and secure – high above the ground, streetlights are protected from vandalism and pose no hazard to citizens.

The one major thing that has been missing for streetlights to be the perfect base for smart city sensors is the lack of a data connection.


LED: the catalyst for streetlight connectivity

Across the world, streetlights are getting a makeover and switching to reliable and energy efficient LED technology. LED street lighting is very adaptable, so lighting levels can be varied according to community preferences (lower to enable dark skies, higher to combat the fear of crime), adapted dynamically to the traffic levels on roads, to suit special events or the needs of first responders.

To control these smart capabilities the streetlights need to be connected to a Central Management System (CMS), which in turn needs each streetlight to have a wireless data connection. And the ideal moment to install the wireless control nodes is when the lights are being switched to LED. So in many countries, the LED and CMS are installed together in a single project, and the result is that all streetlights become connected, and their potential to be hubs for smart city sensors is unlocked. The logic of adding connectivity when switching to LED is compelling, but across the world, most LED projects leave streetlights isolated.


Business case: too narrow, too short-term

Why do the majority of LED conversions take place today without adding remote control and the connectivity that comes with it? It all comes down to the business case for LEDs. Lighting departments within municipalities are responsible for delivering an effective lighting service for citizens, and budgets are always tight. These departments are not responsible for delivering a smart city platform for the future. But the fact is that adding wireless controls has a proven business case.

Major additional energy savings can be made by dimming lights when they are not needed. Also, maintenance cost are reduced, since lights precisely report their own faults and that eliminates unnecessary and faults are fixed on the first visit. These benefits alone are usually enough to pay for the connectivity within five years. The case for controls becomes overwhelming when you add the value of being able to change any aspect of the lighting over time, and then add the value of connecting every light to become a potential sensor hub. But until these strategic benefits are part of the business case for LED projects, many cities will be left with beautiful street lighting that is unconnected, uncontrollable and can play no part in future Smart cities projects.


A bright (and connected) future for smart street lighting

Many cities are breaking the silos and have seen the benefits of taking a holistic approach to smart city applications. This has enabled municipal lighting departments to broaden the scope of the LED conversion business case to include smart connectivity. Cities are now beginning to add sensors to their streetlights as a way of providing more detailed street-by-street data.

In air quality monitoring, for example, imagine if the handful of existing city monitoring stations could be complemented by streetlight-connected sensors on every street corner. These hyper-local insights help city leaders make better decisions and in time will create automatic data-driven city services for citizens.

This article was first published in Smart Cities World 02 Feb 2018.

Topics: IoT, smart streetlights, smart city