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Margaret Ranken, principal analyst, Machina Research

Last month’s article from Machina Research looked at the potential for connected lighting to incorporate sensors that will help drive a range of new smart services in buildings. Connected street lighting has the potential to play a similar role in Smart Cities. As part of our new Smart City Research Stream, Machina Research has looked in depth at a series of Smart City applications including smart waste bins, smart traffic lights, smart parking, road traffic management, public transport, CCTV and social WiFi as well as smart street lights. Of them all, it is smart street lighting that has the most compelling business case and the potential to drive investment in Smart City infrastructure.

Smart street lighting brings huge savings for city budgets

Street lighting is a big part of most city budgets, accounting for as much as 40% of expenditure. The biggest element of this cost is the power, but checking for and replacing burnt out lamps is also significant. Some cities faced with budget cuts are alarming their citizens with plans to switch off lights to save money, but a much smarter approach is now possible.

New lighting technologies can reduce the cost of powering street lights by 30-60% by replacing sodium lighting with LEDs or other energy saving lamps such as white fluorescents or induction lighting. Many cities are taking the opportunity to add smart controls to reinforce the business case and increase the energy savings by a further 20-30%, through dimming lights at times when full brightness is not essential or even switching off lights individually on schedules. On top of that, maintenance savings of 50% can be obtained from the combined effect of the longer life of the new lamps – 15 to 20 years rather than the 5 years for sodium vapour lamps – and eliminating the need to go looking for lamps that are not working because the M2M control systems send an alert when a light fails. Of all the Smart City applications, smart street lighting is the one that delivers the biggest ROI in the shortest time.

Creative funding strategies are needed

Despite the compelling business case, upgrading all the streetlights in a city is a big investment and cities are having to find creative approaches to funding such as: public-private partnerships; issuing bonds; or working with energy service contractors (ESCOs) which upgrade the streetlights in return for a share of the energy cost savings. Apart from the cost there may be other barriers such as:

• street lighting owned by a utility with no incentive to save on energy costs
• third party contractors managing street lighting on existing long contracts that mean there are few cost savings associated with reducing consumption
• electricity tariffs that make off-peak electricity (i.e. at night, when lighting is required) so cheap there is little incentive to dim.

Soft benefits can strengthen the case for funding. Better street lighting can help to make people feel safer, increase the use of public transport and even boost tourism. Smart street lighting systems can allow city managers to adjust lights in an area based on things like whether it’s a high crime area or a sleepy suburb, and make adjustments in real time, for example if there has been an incident light levels can be increased to help the emergency services.

Smart street lights provide the opportunity to connect a range of sensors

Once the street lights have M2M connections there is the opportunity to attach other sensors to take advantage of the power and connectivity, just as there is in buildings. In fact Las Vegas has deployed the Intellistreets system, originally designed for large venues, that can change colour and be used to play music and make announcements to create a ‘memorable’ environment. However, it can also be used to record audio and video which has given rise to privacy concerns. Most cities are looking at the possibility of using sensors for more mundane tasks such as traffic, noise and air quality monitoring. Sensor-based street lighting takes this further and adjusts light intelligently to circumstances, sensing whether there are people in the vicinity or if there is snow on the ground. Copenhagen has experimented with street lights linked to traffic lights so that when a bicycle crosses a junction the lights get brighter to make sure the cars see it.

Smart street lighting drives Smart Cities

The compelling business case for Smart Street Lighting means that it is likely to be one of the first smart city applications to be rolled out, even in smaller cities that find it hard to justify investment in things like smart public transport or community WiFi. But the very nature of street lighting means that it covers the whole city with an intelligent infrastructure that can be extended to support other facets of the smart city. This makes smart street lights the ‘killer application’ for Smart Cities.