Turning Auckland’s 110,000 street lights from yellow to white in suburban areas is well underway.
All older yellow high pressure sodium lighting in the city is to be replaced with new technology light emitting diode (LED) street lights by about 2025. Including the 9,000 lights in the Rodney area.
The first stage of fitting 44,000 LED residential street lights, has been underway around Auckland for the past 18 months.
The lights use just a third of the electricity the older style lights use, and last four to six times longer. They can be directed, which cuts down on light pollution, and hooked up to a central management system. They can also be dimmed for further savings.
This has the potential to save the city $32 million over the 20 year life of the lights.
Along with being able to stand up to traffic vibration and high wind better, colours look more like they do in daylight and show more detail. Their materials are also easier on the environment.
So far 17,000 lights have been changed and connected to a central management system which can control the lights including dimming in off-peak times. Less than one thousand have been changed in the Rodney area so far as there is a lack of coverage of the CMS, Auckland Transport spokesperson Mark Hannan says.
Research into the effects of LED lighting on people’s health is seeing some overseas cities now changing the type of LEDs they use.
The whiter the LED light the higher the amount of blue light it emits. Blue light has been shown to cause glare and can be uncomfortable to look at especially for older drivers.
Coming from computer screens and mobile devices as well as energy-efficient lighting in the home replacing old tungsten lights, our exposure to blue wavelengths is increasing.
Beneficial during daylight hours boosting attention, reaction times, and mood, blue wavelengths can be disruptive at night. It can suppress the production of melatonin, which affects circadian rhythms in our bodies and disrupts sleep patterns.
Lowering brightness on screens in the evening, or apps like f.lux will reduce the amount of blue light that you see from your computer, tablet or phone. Warm LEDs rather than white LED lighting at home helps.
After concerns were raised by the American Medical Association, some cities in the US are now changing LED street lights which have a strong white light. Measured in Kelvin these lights sit in the 5,000 to 6,000 K range.
The Association is recommending authorities use low temperature LEDs of up to 3,000 Kelvin. They have less blue light in them and give off a warmer looking light.
Hannan declined to say what Kelvin range the LEDs currently being installed are.