22 Feb
2010
22 Feb
'10
10:29 p.m.
On 22 Feb 2010 at 23:01, Jochen Kunz wrote:
Well. I meant LED in general, white in special, in
contrast to e.g.
CFL, HID, sulfur, ... Also take in account that the human eye has a
fairly low sensitivity for red light. Lumens are weightend by the
spectral sesitivity of the human eye. -
LED street lights are beginning to appear on some California streets.
As I understand it, there is less light output in absolute terms, but
the overall effect is one of providing more useful illumination than
the traditional high-pressure sodium lamps. See:
http://cbs5.com/video/?id=48013 at kpix.dayport.com
for a video report.
At amazon.com, you can even purchase a 100 watt LED luminaire for
US$720.
http://www.amazon.com/Energy-Saving-Street-Meters-
Illuminated/dp/B000QY0L54
In my lifetime, I've seen street lighting move from incandescent to
mercury vapor (horrible light quality) to low-pressure sodium
(yellow) to high-pressure sodium. LEDs look like a winner and may
well reduce some of the night-sky "light pollution".
--Chuck