Light Pollution is a growing issue in our towns and cities. It can cause interruptions in peoples sleeping patterns and other, adverse health effects. Conventional street lighting use old fashioned incandescent light bulbs are a big source of light pollution. In urban areas they can lead to the whole night sky being lit up, blocking all natural light sources apart from the moon and the brightest stars in the sky.  The Bortle scale is a measurement of the nights sky brightness. 1 is “excellent dark sky” 9 is inner city sky. It’s believed most residents of the western world haven’t seen a night sky darker than 5 on the scale thanks to artificial incandescent light blocking out the sky.

The unidirectional nature of incandescent lights spill light into areas where it’s not needed causing light pollution. As a modern alternative, LED streetlights can be used as a directional alternative. Professionally fitted they are able to illuminate streets with no over spill of light into unnecessary areas.

A LED lamp is much brighter, using as low as one tenth the energy of the incandescent alternative and uses a more natural, white light.

Comparison of lighting colors and intensity of the new LED streetlights (left) and the older high-pressure sodium vapor lamps (right).

To further combat Light Pollution, smart lighting solution are being developed and will become a reality within the next 5-10 years around the world. Smart lighting works on a similar principle to a security lamp you might have in your back garden. It would consist of a LED street light dimmed to 20% of the lamps intensity, roughly the level of light you’d expect in an intimate restaurant. When a person or vehicle is detected the light would switch up to 80-100% of the lamps intensity. This solution gives people full light when required, cuts down on light pollution and massively reduces energy usage when it’s not required.

As an example of how light pollution can cause such a massive difference to an urban area; here’s an image of San Francisco by night:

There is still a long way to go with the development of LED street lamps and smart lighting solutions and the way they’re being implemented around the world. Considerations have to be made for people’s reaction to such a massive change and accepting the way it’s being implemented, but these changes will be noticeable in the not too distant future as councils look for ways to save on energy bills while not sacrificing street safety.

Tags: Bortle Scale, LED lighting, LED Street Lighting