Streetlights

Many years ago, when I had money - before I bought my house in May 2006, before I lost my job nine months later, before I took my new job at a 1/3 pay cut six months after that...actually, well before any of that, back in 1997 or 1998, based on the office I remember sitting in at the time I thought about this - I contemplated making a gift purchase for the city of Nanticoke: a dozen or so Hubbell Skycaps. Back then these aluminum bells for shielding and redirecting the glare of outdoor mercury vapor lighting sold for about $25; as of 2002, when this article appeared in Sky & Telescope, the price had jumped to $35, plus $10 shipping; as of March 2010, Green Earth Lighting (formerly Outdoor Lighting Associates) is selling them for $72 apiece, or two for $124. (There would have been two conditions to this gift: the city would have had to handle the installation, and, dammit, I wanted the first ones to go on the streetlights outside my house.)

Looking at this now, I don't even know if these shields were designed for city street lighting - everything suggests that they're for residential security lights. But surely there must be something similar that can be attached to existing corner lights. These are just inefficient, wasteful, and dangerous beasts: they send much of their light into places where it isn't wanted (like the windows and walls of surrounding houses, and the eyes of passing drivers, whose ability to see at night is compromised by the glare of intense lights shining directly into their eyes) or isn't needed (like into the sky, producing a milky-white skyglow in places where mercury vapor lights are common, and an orange-yellow skyglow where the prevalent lighting is from sodium vapor). They are also self-defeating in terms of security: they provide just enough illumination for nighttime miscreants to go about their business, but create sharp and dark shadows where anyone or anything could hide.

The economic crisis is hitting local governments hard. Colorado Springs has shut off a third of its streetlights, a move surely applauded by some who remember what the sky used to look like at night. But with properly shielded and directed lighting, any municipality could easily cut back on the number of streetlights being used without cutting back on the actual amount of useful illumination. It would have been cheaper to have done it back in 1997, or in 2002. But it's still something that local governments should consider.


See also:
The International Dark-Sky Association - http://www.darksky.org/
SkyandTelescope.com - Saving Dark Skies - Your Home Lighting Guide