Since the inception of the street light, artificial light at night (ALAN) has made our communities safer and improved the quality of life for billions of people around the world. We also know that the natural cycle of light and dark governs our sleep and the behavior of the ecosystems in which humans, animals, and plants live.
As we continue to seek out the benefits of artificial light at night – in our homes, on our streets, and even on our farms – it’s important to keep in mind that more than 80% of the world’s population is exposed to ALAN. With the right lighting solutions in place, we can take measures to enhance our surroundings, while preserving the night sky.
Safer environments that preserve the integrity of the night sky
Populated areas are lit to keep our communities safe. According to research conducted by Signify and the World Council on City Data, upgrading to connected street lighting can reduce crime rates by 21%, as well as reduce nighttime traffic accidents by 30%.
With the right lighting designs and technologies, we can deliver the same safety benefits while preserving the night sky, limiting reflected light, and minimizing how much light is emitted. For instance, street lights can be outfitted with sensors to switch on only when motion is detected, and smart optics take this one step further, directing the light only to where it is needed, avoiding any emission of light where it's not needed.
Efficient lighting, only when we need it
Connected lighting systems can program lighting to automatically dim or switch off at certain hours of the night, when there is little or no human activity. This can deliver reductions in overall energy use for municipalities, where public street and area lighting can account for as much as 40% of a city's electricity consumption.
Telensa, a Signify brand, offers connected solutions for streetlighting that enable centralized scheduling of all street and area lights in a city. This makes it easy to manage and modify lighting behaviors based on seasons, animal activity, events, and other considerations. Connected lighting technologies like Telensa ensure that only the necessary light is used, reducing energy costs and supporting emissions reduction targets.
Protecting natural ecosystems
Too much light at night can disturb our natural sleep cycle, and can impact the behavior of wildlife. Fortunately, street lights can be adjusted to reduce sky spill, which DarkSky defines as the 'unwanted spillage of light onto adjacent areas,' and programmed to automatically switch off or dim when not in use.
The Dutch town of Zuidhoek-Nieuwkoop, for example, installed bat-friendly street lights from Signify to “protect [the] local bat species with minimal impact to their habitat," as explained by Guus Elkhuizen, City Council Member for the municipality. These street lights are specially designed to emit red light at a wavelength that doesn’t interfere with the bats’ internal compass, while still providing enough illumination to keep residents feeling safe.
Illuminating responsibly
To deliver the light we need to go about our lives while preserving the integrity of the night sky, we need to find a balance. Connected lighting management systems, motion sensors, and specially designed LED light recipes demonstrate just some of the ways that technology can be made more friendly to natural ecosystems without sacrificing people’s visibility or sense of safety.
The good news is that the right technology exists today. City leaders should now set the right requirements and measures to implement it, with a clear understanding of the impact that lighting can have on our surroundings.
At Telensa, we advocate for the following techniques as a powerful way to illuminate responsibly:
- Conserve: Use only when and where required. Set time schedules, curfews and use motion detection to optimize energy savings.
- Contain: Direct light only towards the intended surface. Choose and install luminaires with the right optics to prevent unnecessary light spillage.
- Control: Dim to no brighter than necessary. LEDs allow for full flexibility with light levels, so you use only as much as required.
- Color: Use warm white light. Limit the amount of shorter wavelength (blue violet) light emitted where possible.
Learn more about Signify’s commitment to sustainability.