The market for connected streetlights is set to hit 62.9m units in 2025, with a 15.2% penetration in smart city platforms, according to Rethink Technology Research.
 
The research found that the $5.2bn annual market still had massive potential, as LED lighting stocks can be retrofitted with smart city platform adopters.
 
The market for connected streetlights (CSLs) has been largely driven by the introduction of LED lighting, which gave adopters huge savings on their energy bills. However, now that the low-hanging fruit is dwindling, as old analogue lights die off, the CSL market needs to embrace the smart city opportunity, says the report, to become inextricable partners in the formative years of the smart city market, providing both a standalone application as well as the networking infrastructure on which to build additional functions.
 
To this end, it says there will be some 62.9m CSLs in 2025, in a market worth $5.1bn. However, based on the research, the number of these lights that will be directly integrated into a smart city platform (SCP) and used with other smart city applications will only reach 9.6m, or 15.2% of all CSL units deployed. This is despite nearly a full decade of the majority of CSL tenders including some element of SCP functionality.
 
“While this sounds discouraging,” said a Rethink statement, “it is worth remembering that the street lighting market is quite slow moving, and that cities are not exactly fast movers. This early penetration level is not as disheartening as it might first appear, as these contracts typically span over twenty years, which presents a lengthy window to migrate these lights to an SCP. Of all the IoT markets that we track, smart city does seem to be the most gradual, but it has unmatched scale in terms of the economic weight it represents globally.”
 
There are between 300m and 500m streetlights globally, depending on how they are defined. For pole-based lights, the number is closer to 300m, likely around 350m, with the rest of the upper estimate accounted for by lights on buildings, in street furniture and some scene lighting.
 
For cities, lighting has almost always been the largest ticket on the energy bill, and the sales pitch for the LED vendors was that simply swapping from old analogue luminaires to new digital LEDs would save around half of the old energy bill. This freed up cash could then be spent elsewhere in the city, to the betterment of the taxpayers. It is thought that around 20% of the lighting stock has been converted to LED to date, meaning that there is a lot of room for growth in LED, as well as in the supporting CSL offering.
 
Street lighting is vital for a healthy city environment, helping citizens move through the city at night, to enjoy its facilities after the sun has set. Old gas lighting was a major driving force in the Industrial Revolution, helping accommodate all those agricultural workers that migrated to the cities in the wake of the Agricultural Revolution. Street lighting helped societies tackle the rampant crime of the burgeoning cities and, over time, this has evolved to the point where residents can make use of the city at any time of day, in a relatively safe manner, surrounded by other citizens and motor vehicles.
 
With lighting being so important, it is not something that a city can skimp on. In the awkward transitional years between digital and analogue lighting, there were a number of attempts to cut power bills by turning off street lights in quieter areas, leading to outcry from citizens who suddenly realised just how afraid of the dark they actually were. Now, LEDs alone have removed much of the concern that drove such abortive pilot projects, but CSL brings more to the table than just the cost of powering them.
 
CSL deployments let cities schedule and coordinate lighting levels to match the local conditions, to ensure that the city is always appropriately lit and not wasting power. The dimming capabilities of LEDs also allow for dynamic lighting choices, to illuminate areas of interest in cities with tourist attractions, create ambience in desired locations, and increase the brightness to respond to conditions on the ground. This would include increasing lighting levels at the request of the police responding to an incident, or turning the LEDs down when there are no citizens around who need illumination.
 
Those are the main examples of the application benefits LED lights afford, but there is a significant operational benefit to be enjoyed too. LED units last much longer than older analogue, and so involve less truck-roll expenditure to support, meaning that the operational costs for a deployment can also be reduced. But what CSL brings to the table is the ability to slash this upkeep cost even further.
 
The connectivity lets the network identify luminaires that have failed, removing the need for manual inspections, so an engineer only has to make visits to the necessary units. Anomalies in luminaires can be reported back to the central management system, which could indicate a looming failure that could be fixed pre-emptively.
 
“For many cities, CSL finally gives them a way to accurately see their lights’ power usage, which can then be used to renegotiate contracts with their energy providers, as some regions rely heavily on unmetered connections for the street lights,” said the statement.
 
The CSL fleets also provide a foundation on which to build other smart city applications. In the past few years, the sales pitch was that the energy savings could provide the funds needed for new applications, such as environmental monitoring, traffic monitoring, and public transport and safety improvements.
 
“However, our industry conversations suggest that the enthusiasm for these projects from cities themselves is quite muted,” said the statement. “In many cases, the city wants a standalone application that can be treated in isolation, with many buyers wary of vendor lock-in and the problems of scaling that have plagued so many in the IoT. There seems to be a consensus among vendors that the adoption of SCP and then the integration of CSL into them is a long way away, and that the mentions of SCP capabilities in the tendering process are effectively token lip service.”
 
But integrating CSL into a wider SCP could be transformative. The CSL’s networking capabilities can be used by all manner of other smart city applications that might not be capable of justifying such a network deployment in isolation, but which could piggyback on the connections between these lights and the SCP.
 
This would include things such as environmental sensing, particularly air quality and noise pollution, presence detection and footfall analysis, to guide dimming schedules as well as provide data for the city to use in decision making, and more advanced data-heavy tasks such as video analytics for traffic and pedestrian routing, and public safety, including flood and weather warnings. This network could also be opened up to community and citizen projects, which might not be able to afford to build or lease a network independently.
 
“All these applications could be built upon the foundation that CSL inside an SCP provides, but the lack of enthusiasm has to be overcome first,” said the statement. “To do this, there needs to be proven returns on investments in the smart city market, which is considerably more difficult when benefits here can be more easily measure in societal improvements rather than dollars.”