INVERCARGILL will be getting new street lighting but the lighting’s potential colour is raising debate.
The New Zealand Transport Agency (NZTA) is offering the Invercargill City Council (ICC) an 85% subsidy if it fast-tracks installing LED street lighting in place of existing high-pressure sodium lighting.
ICC roading manager Russell Pearson said at a meeting of the council’s infrastructure and services committee last month that replacing all the city’s 7000 or so street lights in the next 12 to 18 months would cost about $2,850,000.
Of that, the NZTA would contribute $2.4 million.
Mr Pearson said the council would recover the deficit in about seven years through the LED lighting’s energy savings and lower maintenance costs.
Councillors at the meeting agreed to give the new street-lighting project the go-ahead.
However, after the meeting Mr Pearson said deciding the best colour temperature for the lights was unresolved.
Royal Astronomical Society of New Zealand’s director of dark skies Steve Butler, of Invercargill, has cited international research revealing the detrimental effects of LED lighting on human, animal and plant life.
“It’s a very complex issue, but we need to be sure before we’re committed to the full introduction of the new technology and light that LEDs bring. There’s a need for further and full research to drive the rules and limits which should apply to the use of blue-rich white light at night.”
The NZTA has recommended lighting of 4000 Kelvins.
An NZTA spokesperson said the agency was “aware of the alleged blue light risk associated with white light sources such as LED”, but light pollution from houses was “probably” greater.
The agency had recommended 4000K because it was the “best compromise between safety performance and energy use”.
Mr Pearson included two options for lighting colour in his report to council – 3000K or 4000K.
His plan was to install 3000K street lighting in residential areas but 4000K on main streets such as Dee St.
However, this would not be confirmed until a meeting of roading managers from the ICC, Southland District Council, Clutha District Council and Waitaki District Council to be held on Monday, July 10, he said.
“We’re talking about and following up the 3000K angle and a lot of consideration has been given to some of these medical reports. Selection of colour is a pretty serious consideration.”