One of the main challenges associated with smart city systems is the installation of thousands of data points throughout cities. Each one of them must be able to gather information on traffic, energy consumption and other key variables, while being capable of bidirectional communication with a control system and a cloud-hosted database. Deploying such a system from zero would be prohibitively expensive, but there is already a platform on which it can be built: street lighting.
There are two main reasons why streetlights offer potential to become communication hubs for smart city systems: they are located everywhere, and they are connected to a power supply. The following are some examples of promising upgrades for streetlights:
Solar photovoltaic panels
Electric vehicle chargers
Communication hubs (4G and Wi-Fi, eventually 5G and Li-Fi)
It is important to note that many of these components have significant space and load-bearing requirements, so it may be necessary to redesign conventional light poles for them to be feasible.
Upgrading Streetlights to LED
There are two strong reasons to upgrade street lighting to LED: energy efficiency and improved street safety. Both benefits are hallmarks of a smart city.
Energy Efficiency of LED Streetlights
Power consumption can be drastically reduced, providing energy savings while alleviating the local load on the power grid. For example, energy savings above 50 percent are common when HID lamps are replaced with LED lighting, and may exceed 80 percent if lighting controls are also implemented.
The impact of upgrading multiple street lights can be significant. For example, if 10,000 HID fixtures with a power consumption of 450W each are upgraded to LED, with a consumption of 180W per fixture, total power consumption is reduced by 2.7 megawatts.
Improving Street Safety
Streets can become safer, since LED lamps are more reliable than their HID counterparts: they offer a service life that is up to 10 times longer, and lamps do not require a cooldown period when turned off. Having no cooldown period enhances street safety, since streets are not left in the dark for several minutes after a power supply interruption.
If connected LED streetlights are equipped with a camera, they can also provide direct street monitoring, further contributing to public safety in smart cities.
Streetlights as Distributed Energy Resources
If streetlights are equipped with renewable generation and energy storage, they can also become distributed energy resources, contributing to the creation of a smart grid. Although solar panels are heavy and installing more than one per light pole is unfeasible with current technology, the aggregated capacity throughout and entire city can be significant. For example, if the 10,000 street lights in the example above are equipped with a compact 100-watt solar panel each, one megawatt of distributed capacity is achieved. Of course, if technological development allows solar modules to become lighter and more compact, the potential generation capacity per street light will increase.
As a complement to renewable generation, streetlights can include energy storage and electric vehicle charging stations. As EVs become more common, streetlights would start to take over the role of conventional gas stations, and would also be able to use their energy storage capabilities for demand-side management. Finally, they would also contribute to absorbing peaks in generation from solar arrays in residential and commercial buildings that are not equipped with energy storage.
A smart city where all streetlights have been transformed into DERs would be much less vulnerable to electric service interruptions, since there is a significant generation and storage capacity distributed throughout the city. Energy generation and storage can achieve great synergy with LED lighting, since reducing the current drawn by each lamp also means there is more energy available for storage and demand-side management.
Data Acquisition and Communication Hubs for the Smart City
Streetlights with sensors and communication hubs can become the backbone of all smart city systems. They could be used to provide a real-time snapshot of multiple city conditions, including:
Wind speed and direction
Events requiring urgent attention, such as accidents or criminal activity
In addition, streetlights would be able to send control signals to any device capable of interfacing with them. To make this possible, they can be configured to use multiple communication protocols, including GSM, GPRS, 4G and Wi-Fi. Communication systems should be modular, allowing an eventual upgrade to 5G and Li-Fis these technologies reach the mainstream market.
Connected streetlights also offer a convenient platform to deploy LoRaWAN, a subtype of LPWAN (Low Power Wide Area Network) intended for wireless and battery-powered devices. Like LiFi and 5G, LoRaWAN could be a key enabler of the Internet of Things.
The Internet of Things (IoT) & the Internet of Energy (IoE)
Billions of new devices are expected to be brought online over the next few years, including electric vehicles, exceeding the capabilities of current Wi-Fi and 4G networks. The deployment of new technologies such as 5G, VLC and LoRaWAN will be necessary to accommodate this growth, and LED streetlights provide an ideal platform, which is already located everywhere and connected to a power source.
Li-Fi is a subtype of Visible Light Communication, around 70 times faster than Wi-Fi and with a frequency band that is 10,000 times wider. Once Li-Fi becomes mainstream, LED fixtures will become Internet hubs: they will communicate with any Li-Fi capable device, as well as with each other.
Importance of Partnerships Among Technology Providers
Technology providers can establish business partnerships to offer innovative solutions, and equipping street lighting with energy resources and communication equipment is an example of this. When LED lighting and solar panel manufacturers partner with a company that specializes in measurement and monitoring, they can achieve synergy: their technologies provide more value when operating in coordination rather than isolation.
Logic Energy has a decade of experience providing monitoring solutions for multiple applications, including energy efficiency, renewable energy generation, transportation, scientific research and health & safety operation. Our technology can adapt to any piece of equipment, sensor or software, and offer customizable aggregation reports and round the clock cloud-hosted real time information.
Inverclyde is one of 32 council areas used for local government in Scotland.
We chose to use Logic Energy as it offered Inverclyde Schools a bespoke service that was tailored towards the individual schools needs. We now use the Logic Energy dashboards as part of the school curriculum and to help eco focus groups.
Edward Montgomery Property Services Manager - Inverclyde Council