A three-year smart lighting initiative at the City of London has just been completed, providing a flexible and robust communications network that will support it on its journey to become a smart city. Phil Beecher, president and CEO at Wi-SUN Alliance, which is helping transform the City, discusses the project and the potential for other cities to do the same.

The concept of the smart city is still evolving as we see more and more smart initiatives being rolled out around the world to help meet environmental and sustainability targets, improve citizen safety and manage increased urbanisation. Cities and municipalities are also under pressure to reduce costs and increase efficiencies, as budgets continue to be squeezed.

Street lighting is often the ‘entry point’ on the journey to become a smart city, as the business case for converting streetlights into smart LED lighting is a relatively simple one. LED lights require less maintenance, are more energy efficient and can help to control costs. A local authority can justify replacing old lights with LEDs purely on the basis of costs savings. The incremental cost of including smart communications is relatively small, enabling remote monitoring of faults and lighting control depending on whether pedestrians or cyclists are in the area, or parts of the city need lighting up like tunnels or bridges.

Once you have the network in place, it provides the communications infrastructure for other applications and services, such as parking and electric vehicle charging, waste collection, air quality monitoring and even sensors that measure road temperatures, so councils know when to send out the gritting lorries.

The City of London is one example of a city that has done exactly this. A three-year street lighting project, just completed, is now ready to support other smart functionality like environmental sensors and monitoring of the presence of lifebelts on the river.

The City has a large population of around 450,000 workers during the daytime, and just 9,400 permanent residents at night. But with its famous landmarks and tourist attractions, like St Paul’s Cathedral, there can be as many as a million people at the busiest times.

Managing this number of people can be challenging when it comes to creating a vibrant and safe space to live and work, so the street lighting project has been a crucial part of this. Designed to balance public safety with lighting up some of the most iconic landmarks, it also needed to create the right ambience.

The project was ambitious; the City has a lighting stock of 12,000 lights, which were reaching the end of their useful life. There were also around 45 different types of lights that needed standardising, all of which were on unmetered power supplies that required a lot of effort to rationalise when it came to billing.

Like many other cities, the City of London also needed to manage rising energy costs and reduce energy consumption. Since the street lighting rollout, the project has provided energy savings of approximately 80,000kWh over the past financial year.

The business case was clear, but the challenges were harder to overcome – many unique to the City’s own environment. The City of London has a unique mix of old historic buildings and new high-rises, many of which are constructed from glass, steel or concrete. This can create connectivity challenges for traditional communications technologies like cellular or LPWAN that are unable to reach into the narrow streets and urban canyons between buildings.

For a lighting project on this scale, the City needed a communications technology that could reach into even in the densest, narrowest streets and lanes.

A wireless mesh network supported by Wi-SUN Field Area Networks (FAN) technology has been able to provide the level of coverage needed to connect all of the lights, wherever they are situated. It also provides a robust infrastructure that meets the needs of the City’s lighting management and control, so being able to dynamically change lighting levels and provide fault reporting through a central management system.

The self-forming nature of the network also means ease of installation and use. Once the devices, in this case LED luminaires, are added, they just connect into the network without complicated engineering or installation. If a device fails, of if there is local interference on the network, it simply re-forms to bypass the problems or obstructions.

As an open standards-based platform, Wi-SUN FAN also delivers the flexibility and interoperability to add other smart devices and IoT sensors across the network as and when needed. The City of London is starting to do this to gather key data across its assets and future-proof the City.

Now that the street lighting project is finished, it has already moved onto the next phase of its journey, installing traffic and air quality monitoring sensors in Beech Street as part of an 18-month trial to allow only zero emission vehicles in the area. These sensors will be being used to collect data and help build the business case to invest further in the technology.

Smart sensors are also being fitted on lifebelt holders along the River Thames to alert the authority when lifebelts have been removed so they can quickly be replaced. This initiative was the result of a smart city challenge set by Wi-SUN member company, Itron, to encourage companies to create solutions to address specific challenges set by different cities, including London and Glasgow.

The I-Tech designed solution deploys small, battery-powered devices that monitor the lifebelts and sounds a high-pitched alarm if one is removed. If it’s not placed back in its housing unit for eight seconds, an emergency message is sent via the network to notify emergency services.

Converting legacy streetlights may be the start point for a future smart city, but it’s clear that this is not the end point. There are some innovative and very clever new smart technologies being developed, and while the business case must be made first before a full-scale rollout, the future looks bright for our cities.