Light from cities is a known issue for star gazing. It is a bigger problem for astronomers whose job it is to study the stars.
Signify, formerly Philips Lighting, is installing smart light emitting diode (LED) street lights in Puerto de la Cruz on the Canary Islands that can be dimmed remotely and use special optics to reduce light spillage. This is important in the area where there are a number of observatories studying space.
“Sky glow caused by light spilling from cities into the night sky is an issue for astronomers the world over. The Milky Way is hidden from more than one-third of humanity, including 60 percent of Europeans and nearly 80 percent of North Americans," said Paul Peeters, Business Leader Professional Lighting in Europe for Signify. "Our street lights are fitted with LED modules with special optical plates that filter out blue light and direct the light to the ground. These energy efficient street lights will also be wirelessly connected to our lighting system and management software so that they may be dimmed or turned up remotely."
The Canary Islands is home to several international observatories and the quality of the sky is protected by Spanish law. The Tenerife North and La Palma municipalities are required to mitigate light pollution such as banning the use of high-pressure mercury lamps or white light lamps.
A total of 6,000 street lights will be installed in the region with about 3,000 Philips Luma and 1,500 Philips ClassicStreet luminaires being monitored, controlled and managed remotely using the Signify’s lighting management system. About 1,500 sodium-vapor street lights from existing installations will be added to Interact City, using connector kits as well as the management of 165 cabinets. The lights are expected to yield about 65 percent in energy savings for the city, Signify said.
Included in the installation is a pilot project where 100 Philips SR luminaires equipped with two system-ready sockets to accommodate existing and future sensors from other suppliers — such as noise, pollution or traffic monitoring. Installation of the street lights is set for completion in August.
The LED lights work well for astronomers because they contain special color optics that filter out mainly blue light, which causes sky glow and can shape the direction of the light. The Signify LED modules are about 16 percent more efficient in lumen output than amber LEDs, which have been used in the past to mitigate sky glow. The lights are also friendly to bats to help preserve the environment, Signify said.