From what I’ve seen in recent years there seems to be a bit of conflict between energy efficiency and environmental consideration.
Speaking generally, SON installations have replaced and continue to replace SOX across the country. The benefits of this of course is a whiter light which I suppose is safer in terms of colour distinction. I’m assuming theres some sort of legislation governing lighting levels too?
Perhaps in some cases energy saving too.
Yet due to the design and specification of these lanterns there are plenty of drawbacks. The cut-off nature of many modern SON lanterns means they have to be mounted at a greater height and often greater wattage to get the same spread of light as a bowled SOX lantern. Because the spread of light is narrower from the SON lanterns this means that each individual installation has to be closer spaced. So we end up with column overdose. Also MASSIVE glare and drivers not turning lights on.
I’m not particularly against SON as a lamp type but it depends on the lantern. Although it doesn’t look great I’m starting to quite like the WRTL 2600. It is of course an older design now but where I’ve seen it installed it gives very good distribution without the need for huge columns of high wattages, due of course to its deeper bowl. Same with the MRL6.
Its with these lanterns that part night switching makes sense to me. Scarborough have recently introduced a part night scheme that affects installations old and new.
On Valley Rd the scheme sees every other lantern turn off after about 11pm. The lanterns are MRL6/GEC version which I believe run 150w SON.
https://maps.google.co.uk/maps?q=Valley ... 29,,1,-5.8Even with half the lanterns out this provides a adequate lighting level, with smoother transition between lit areas.
In other areas of the town the same part night switching has been applied to newer lanterns. A road near me has QSS’s running CFL that again see every other lantern off after 11 and because of the cutoff design of the lanterns the roads become like chessboards. It’s not nice to drive or walk through because your eyes never get chance to adapt to the light or dark. I don’t think its particularly safe.
So although this is undoubtedly saving them money I don’t think it’s suitable considering the lanterns installed.