Safeguarding our night sky

The world is losing its night sky. A new study published in Science calculated that between 2011 and 2022, global sky brightness increased by about 9.6% per year. Researchers leveraged the community science project Globe at Night and collected data from more than 50,000 people from around the world who recorded the number of stars they saw on clear, dark nights.

The study revealed a certain place-to-place variability: Europe saw a 6.5% increase in light pollution per year, while North America faced a 10,4% increase. The global average of 9.6% means sky brightness is doubling about every seven years, and this is not good news.

“Increasing sky brightness is a sign we are doing lighting wrong. It’s a sign we are using energy inefficiently, wasting money, exacerbating climate change, and increasing environmental impacts,” states the International Dark Sky Association (IDA).

Over lighted districts and streets affect human health by possibly triggering insomnia and other diseases, but it also has negative impacts on animals and plants, disrupting wildlife, the migrations of birds, the blossoming of flowers, and more. We may object that increased light at night improves safety and discourages crime – but having bright, empty parking lots may serve little purpose.

The true question is not about more lighting in our cities, but about more intelligent lighting. As streetlights are deemed useful and necessary, IDA advises cities for responsible outdoor lighting following a simple principle: light where and when you need it, in the necessary amount, and no more.

“With dimmers, movement sensors and more, the tools exist to light our nights differently,” writes professor Paul Bogard on the Washington Post. Indeed, smart technologies can help a lot. By connecting lamps and controlling them from remote, cities can define customized lighting patterns for single districts and areas. Streetlights can be turned on/off and dimmed according to programmed schedules (ie. setting a default combination for working and festive days, for residential and industrial areas, etc.), changing them whenever necessary to mirror specific local circumstances or events.

Specific sensors allow brightness to be adjusted upon ambient light levels. Lamps may also be integrated with motion sensors, vehicle counters, tilt sensors, and other devices, triggering condition-based dynamic lighting. This is particularly useful in low-traffic areas, where lights may be further dimmed only when no vehicle or pedestrian is passing by.


Interested in a Smart Lighting solution to manage outdoor lighting responsibly? Download our paper 'Smart Lighting: how switched on are you?' and learn more about our Smart Urban Network: you will save up to 80% of power and greenhouse emissions in your city, while safeguarding your night sky.

interoperability smart lighting

Smart Lighting: cities should tender for interoperability

Public lighting management changed a lot since the introduction of smart IoT technologies. Remote monitoring and control are now possible, with immediate benefits in terms of power and energy bill saving, GHG emission reduction, improved maintenance and quality of service.

But how can we ensure connected streetlights benefit the city, its people and the common good? LUCI Association picked on the question in a recent paper, discussing key elements of the technical and operational framework of Smart Lighting, and the social and societal side.

Interoperability stands out as a focus topic. Cities are increasingly worried about vendor lock-in, as proprietary technologies and single-application networks suffer impossible or expensive integration with other systems, run a higher risk of obsolescence and ultimately provide a poor return-on-investment.

As LUCI Association’s paper clearly explains, the concept of interoperability in Smart Lighting comes into play in three levels. The network level is about the carrier of the communication among connected devices; the software level is about the shared language these devices need to interact. The hardware level relates to the physical devices to be interfaced, considering for instance LED luminaires, smart controllers, and environmental sensors.

As a technology provider who has always been agnostic to the application, at Paradox Engineering we focus on the development of smart IoT networks supporting a number of field devices and third-party systems, independently of the make. In a word, we head for interoperability.

Our technologies are standard-based and feature open data models: 6LoWPAN, TALQ, uCIFI Alliance, but also DALI, Nema, Zhaga are some of the industry standards you will hear the most from us.

Interoperability grants cities the flexibility to address the most pressing challenges and strategically plan for future, innovative applications. Less costs today, and no barriers when it comes to adding new devices and applications over time.

Are you ready to tender for interoperability? Contact our experts for a non-binding consultancy about smart interoperable networks for Open Cities!

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Connected streetlights? It’s time for smart adaptive lighting

Street lighting accounts on average for 40% of a city’s electricity bill: not surprisingly, it is one of the first services city managers focus on when challenged with budget constraints or sustainability targets.

Up to 80% in power consumption and related costs can be saved by turning streetlights to energy-efficient LED lamps and connecting them to a wireless Internet of Things (IoT) network. With our PE Smart Urban Network platform, cities can transform their lighting infrastructure into a smart, sentient network and enable full remote control of single or grouped luminaires.

PE Smart Urban Network allows to turn on/off and dim single or grouped luminaires from the central management system, and enables the definition of customized outdoor lighting schedules. Operating hours and brightness can be programmed upon daily solar times or ambient light levels, and default combinations can be set for given districts or areas.

What's more? Our platform enables adaptive, sensor-based lighting. By interfacing streetlights with motion sensors or vehicle detection systems, dynamic lighting can be triggered, further reducing consumed power up to 30%. Adaptive lighting patters can be defined, ie. turning lamps on in real time upon vehicle or pedestrian transit, reducing brightness in low-traffic areas or empty roads.

Look at this example: Along a bicycle path, street luminaires can be preset to remain off with daylight and provide light intensity at 40% at night. Thanks to the integrated motion sensor, when the environment light is below the 50 lux threshold and a vehicle is detected, the light level is increased from 40% to 100% for 2 minutes.

smart adaptive lighting

Lighting can dynamically mirror traffic intensity. Light points can be integrated with vehicle traffic counters to track the number of cars passing through in a given timeframe. When a specific threshold is overpassed, an automatic command is sent to set a group of lamps on a pre-defined dimming level.

For example, an IP camera can be configured to count vehicles crossing a couple of lines, resetting counters every 15 minutes and sending the related command to dim lights. Three scenarios are considered: with low traffic condition, dimming level is set to a minimum of 40%; medium traffic raises dimming to 50%, and high traffic to 70%.

smart adaptive lighting

The dimming control can be also based on Lux, rain and environmental sensors measuring wind intensity, temperature, humidity and pressure. Supposing the physical data to be collected every 5 seconds and correlated with related thresholds, a command is sent to LED drivers over the DALI2 bus to adjust lighting levels.


Want to learn more about PE Smart Urban Network and adaptive lighting? Watch our webinar and feel free to contact our Smart Lighting experts to have all your questions answered!

Bringing smart lighting to decentralised cities and rural areas

In 2020, over 56 percent of the world’s population was urban, and the United Nations estimated that urbanisation could reach 68 percent by 2050. However, the Covid-19 pandemic may curb this trend, as the rise of remote working may encourage more people to leave cities in search of a different way of life.

The future may be about decentralised cities, making the traditional metropolis model evolve towards polycentric, multi-nodal conglomerates. This would create a “new normal” for urban density — and push urban IoT infrastructures to change accordingly.

What does this mean for Smart Lighting? The standard case for street lighting is about city centres or densely clustered areas, where it is generally simple and cost-effective to upgrade existing lamps to LED and design a mesh IoT network. Once connected, smart luminaires can be monitored and managed from a centralised software system, while some gateways act as border routers, network coordinators, and data concentrators. Under normal operating conditions, a single gateway can manage up to 400 connected streetlights.

If considering decentralised cities or rural areas, the scenario may be completely different. Think of suburbs and countryside villages in Europe or the US, for instance. Due to the low population density, we may have dispersed groups of a few streetlights, or even single isolated lamps. This makes it difficult and expensive to reach them, as more gateways would be needed to reliably connect them to the mesh network.

Installing more gateways to connect hard to reach streetlights increases complexity and generates additional costs, as average costs per light point soar. What if we had a different lighting device serving both as a node and a gateway? May it connect single or isolated group of lamps to the existing IoT infrastructure?

Read more on Cities Today!


Switch off streetlamps to fight light pollution

Paris is acknowledged to have installed the world’s first electric streetlights back in 1878. Three years later, 4,000 electric lamps were in use in the French capital and gas lanterns were gradually abandoned. Today, there are about 326 million streetlights all over the world, and this should grow to over 361 million by 2030. About a quarter of all streetlights globally have already been converted to LEDs and over 10 million have been connected to smart networks.

If we sum streetlights to lights beaming from homes, skyscrapers, shops, office buildings, and billboards, it is easy to understand our cities are over illuminated. Light pollution – which scientists define as the alteration of night natural lighting levels caused by anthropogenic sources of light – affects more than 80% of the world and more than 99% of the U.S. and European populations. The Milky Way is hidden for more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans.

Authoritative bodies such as the International Dark-Sky Association (IDA) are vocal in asking for urgent intervention to reduce the skyglow, the brightening of the night sky over inhabited areas. Many cities are discussing possible measures: in the US, the City of Pittsburgh presented a “Dark Sky Lighting” ordinance to introduce strict criteria for all newly constructed and renovated facilities and parks, and a mandate for all streetlights to utilize Dark Sky-compliant fixtures. The ordinance should be discussed later this month and might serve as a model for other municipalities looking to effectively reduce light pollution.

Light pollution has a remarkable financial and environmental impact. IDA estimates a third of all outdoor lighting in the US is wasted, costing facility owners some 3.3 billion USD annually and releasing 21 million tons of carbon emissions annually. But the widespread use of artificial light is also proven to interfere with people’s mental and physical health, as well as with wildlife and the natural habitats of plants.

The immediate solution we might think of – let’s turn out every light at night – is not such viable. Modern life requires lighting, specifically night street lighting is essential to make road mobility secure and improve public safety. In 2018, the New York City Crime Lab investigated some 80 public housing developments for a period of six months, measuring the effects of the introduction of new streetlights in around half of them. The study found that index crimes decreased by 7%, while night crimes dropped about 39%.

So, the real challenge is to responsibly and intelligently manage outdoor lighting to reduce pollution without jeopardizing quality of service. As reported by BBC, Tucson, Arizona, converted nearly 20,000 sodium street lights to dimmable, energy efficient LED lamps. Light pollution due to streetlights reduced from 18% to 13%. Since 2018 the city has cut its total light emissions by 7% and its annual energy bills by 2 million USD. Additional measures are being implemented to switch off advertising billboards, floodlights, buildings, and sports stadiums.

PE Smart Urban Network is our performing and reliable IoT platform for Smart Lighting: it allows to connect and control districts, streets, and even single lamps from a central management system, turning lights on/off and dimming them according to programmed schedules, environmental conditions or on demand.

Thanks to PE Smart Urban Network, cities can mitigate light pollution and save up to 80% of power and greenhouse emissions: learn more about our solution and join our community to access white papers, brochures, videos, and other insightful resources.