LONDON - Are LED streetlights bad for us? This was perhaps the most contentious topic up for discussion at LuxLive last week.
With a panel that pitted streetlighting quality campaigner Simon Nicholas against various representatives of the lighting industry and of local government councils, the most surprising thing was that the panel mostly agreed: LED streetlights can be harmful, but they don't have to be.
‘Local councils are being led down the garden path,’ argued Nicholas, who noted that when private investors back public street lighting schemes, local authorities often skip over important evaluations that could reveal problems with glare, with patchy light, and with light that is too tinged with blue - a 'cold' colour temperature that many consider to have harmful health effects.
Independent lighting designer Kevan Shaw objected that manufacturers, rather than lighting designers, typically oversee street lighting layouts and thus place an overarching priority on minimising costs rather than on optimising design.
‘Independent lighting designers don’t get to do streetlighting design,’ Shaw noted.
The panel agreed that simply retrofitting new LED heads on old columns was often a bad idea, because the spacings aren’t right for the characteristics of LEDs.
But it was split on the problems posed by blue LEDs, which, Nicholas argued, harm both human health and the environment. Trafford-based Nicholas has assailed blue LEDs for disrupting circadian ryhthms and for possibly causing brain damage.
It may be a moot point, according to Dave Franks of Westminster City Council, which only installs LED streetlighting with a colour temperature of around 3000K, much warmer than the blue spectrum.
LEDs with cooler colour temperatures have historically been cheaper and more powerful, but warmer temperature technology has improved and become more viable.
Meanwhile CU Phosco’s David Lodge pointed out that the uniformity of LED streetlighting can exceed what’s possible with traditional sources.
If streetlighting isn’t independently designed, local authorities need in-house expertise to assess the merits of a design - and Westminster's Dave Franks said he and his peers should be ready to accept the responsibility for good or bad streetlighting. ‘Why shouldn’t I be accountable?’ Franks asked.
But Nicholas worried that authorities up and down the country are pressing on with the wrong kind of LED streetlighting because they committed to schemes conceived at a time when blue light and other wrong-headed ideas prevailed.
‘PFIs take years’, Franks sympathised. ‘Those are old designs.’
How do you finance LED streetlights? LuxLive had a few answers, like this one:
Be careful what you wish for? Lux has delved into the pros and cons of LED streetlighting in scores of stories. Here are a few. Follow their links for more:
- UK town: If only we had known about LEDs
- European Commission: Funding available for multi-city smart lighting development
- The pitfalls of savings-based LED streetlighting deals
- Flashing LED streetlights will direct cops to emergencies
- LEDs drive 'smart city' in bold Danish experiment
- New Orleans residents not jazzed by LED streetlights
- Protets mount against streetlight switch-offs, 'dangerous' LEDs