I read a really interesting section of the VDOT street lighting code. Basically they try really hard to eliminate glare and light pollution. However, that goal competes with the goal to use fewer fixtures. If you have full-cutoff lamps on a traditional HPS ballast, they only illuminate a small portion of road instead of an entire interchange, for example. That is why they end up with quite a bit of LP.
If this LED stuff is used properly it could be really good. However LEDs are also bad because they tend to produce light across the entire spectrum. At least with sodium lamps the maximum output is only at certain wavelengths.
Ironically, I suspect if we could all live 200 years we would see a very different, very much darker planet. Energy is going to be the main problem of the next few hundred years. I suspect people will be forced to think hard about energy usage someday, and the skies will get dark again. I doubt I will be around to see it though.
That's a long-long time away. Right now, I was driving on the Interstate. Bright Sun, all the flood lights are still on at 8:30 in the morning. I suspect they'll stay on all day long. So much for cutting light pollution because of the high energy cost...
Harry Armstrong
I read a really interesting section of the VDOT street lighting code. Basically they try really hard to eliminate glare and light pollution. However, that goal competes with the goal to use fewer fixtures. If you have full-cutoff lamps on a traditional HPS ballast, they only illuminate a small portion of road instead of an entire interchange, for example. That is why they end up with quite a bit of LP.
If this LED stuff is used properly it could be really good. However LEDs are also bad because they tend to produce light across the entire spectrum. At least with sodium lamps the maximum output is only at certain wavelengths.
Ironically, I suspect if we could all live 200 years we would see a very different, very much darker planet. Energy is going to be the main problem of the next few hundred years. I suspect people will be forced to think hard about energy usage someday, and the skies will get dark again. I doubt I will be around to see it though.
Apr 27, 2013
Ian G
That's a long-long time away. Right now, I was driving on the Interstate. Bright Sun, all the flood lights are still on at 8:30 in the morning. I suspect they'll stay on all day long. So much for cutting light pollution because of the high energy cost...
Dec 4, 2013