Why LEDs are leading lights
Fears from Palmerston North residents about increased crime, road and personal safety issues, and tripping over on uneven pavements in the dark, have accompanied the changeover of city streetlights to LEDs.
But concerns about the brightness or otherwise of the new lights can be overcome, according to LED lighting specialist Hangfeng Ji.
‘‘Switching to LED lighting is not only for energy saving, but also for increasing the safety of the road and the city,’’ Ji said.
A research and development manager for Biolumic, a Palmerston North start-up company specialising in agricultural lighting, he offered to ‘‘shed some light’’ on why LED technology on our streets had a bright future.
‘‘It’s not a one-to-one switch [from old to new] - it’s not that simple. LEDs are very bright from a highly concentrated source point but they can be diffused. The lights can be designed to to be similar to the old sodium lights.’’
Ji said this can be achieved by using a greater number of smaller LEDs instead of a larger single light, or by using advanced optics around the bulb to create a diffusing effect.
With nearly 10 years in the lighting industry, Ji worked as a scientist for Philips Research in Shanghai, immigrating to New Zealand three years ago.
An inventor with more than 40 patents, mainly in the LED lighting field, he said the LEDs use up to 85 per cent less energy and can last for 10 years.
They could also be combined with other city utilities, such as electric-car charging, security and surveillance, mobile phone base stations and emergency services, he said.
‘‘In other words, LED lighting can not only save energy but, more importantly, make the city smarter.’’
LED technology means further energy savings are possible because the intensity of the light can be reduced by 20 or 30 per cent during off-peak times, he said.
‘‘Lighting on demand’’, Ji said, used sensors to brighten the lights when vehicles or people were detected, and dim them when they were not required.
‘‘Dimming LEDs is very easy but not possible with older lighting systems, which can’t be turned off and on quickly.‘‘
Ji said combining the new and audited LED streetlights with a smart system would benefit everyone, along with a reduction in the city’s light pollution.
Hangfeng Ji is an R&D manager in a startup company focusing in agricultural lighting.