Letter: light pollution
It was amusing to read in the Sunday, Feb. 20, letters page that I had become “misdirected” and “misinformed” in regards to my beliefs about light pollution and the irresponsible use of outdoor lighting. Mr. McIntyre, the letter writer, in rebuttal to an earlier letter of mine, argued that directional lighting could not possibly save energy; that it was even inefficient. I appreciate that he did, however, agree with me that communities should create building codes that help eliminate light pollution. I am hopeful that others feel the need for lighting guidelines also.
I have worked in the electrical industry for the past 30 years, so I certainly don’t have a grudge against electricity per se. Over these years I have been involved in many aspects of electric lighting including the sales and installation of outdoor lighting
There are many large and reputable manufacturers of High Intensity Discharge (HID) lighting that somehow have missed the latest change in the Laws of Physics. They haven’t found out that using directional reflector designs in lighting doesn’t work any more. Perhaps they have wasted millions of dollars in development costs on a lost cause, but I don’t think so.
The use of directional reflectors for lighting is a longstanding idea; early on, engineers learned that a light source could be more efficiently utilized if it could be focused in a useful direction. The last time I checked, mirrors still reflect light efficiently. Our automobile headlights are a case in point; could you imagine, as Mr. McIntyre implies, that unenclosed light bulbs on our car hoods would light the highway as well as the efficiently designed reflector and lens assemblies of modern headlamps? Would the road be just as bright, watt for watt? I think not. The undirected lamps would have to be MUCH brighter to provide the same foot-candles of illumination ahead of you, not to mention the glare!
The inefficiency of such a setup would be very apparent to you, Mr. McIntyre! Much of the energy being used in this bare bulb scenario would be wasted, shining mostly where you didn’t need it. How did putting the reflector and lens into the headlight make it less efficient? The task of lighting the highway (not everything around you) is done with a smaller, lower power lamp. Less energy is needed. Isn’t this greater efficiency?
The same principles apply to outdoor area lighting as well; light directed (or misdirected as is the case) to areas where it is not needed represents wasted energy. Through the use of reflectors, lenses and very efficient sodium vapor lamps, modern HID light fixtures create safe light levels on our highways and in our public areas with less than a quarter of the energy consumption typical of the old mercury vapor “scattergun” fixtures. These HID lamps are small and do not require large, ugly fixtures as was suggested.
When outdoors at night, look around you and you will see many examples of efficient lighting vs. inefficient lighting. The poorly designed fixtures will stick out like sore thumbs due to their glare in your eyes; you will see quite graphically that most of the light is doing nothing at all, save murking up the night sky.
We should encourage the use of well designed lighting around us. The cost of effective lighting fixtures is offset by the energy saved. Directional lighting illuminates areas safely where the light is needed, not glaring into our eyes; it is aesthetically pleasing and, mostly, hundreds of millions of dollars would be saved each year in energy costs nationally. How long must we as Americans be the most wasteful users of energy on Earth? There are communities all around the country that are already reaping the benefits. Like I said before, all it takes is a little common sense and consideration.