Retrofitting the street lights

Can old dropped lens cobra heads be retrofitted with flat lens glass to make them a suitable full cutoff fixture?

No, in addition to replacing the dropped lens or refractor of the fixture, the reflector inside the fixture must be replaced to properly distribute the light spread from the fixture down onto the road. Since the new flat lens fixture is relatively inexpensive compared to the cost of performing this type of customization, it is more cost-effective to replace the old fixture with a new flat lens fixture of the correct photometry.

What can cities do with their old streetlight fixtures?

The City of Calgary embarked on a massive street lighting retrofit. In an effort to be more environmentally sensitive, the fixtures were disassembled and the components – glass, steel, aluminum, etc. – were then recycled. There are a number of pictures on the Website that show streetlight components being readied for recycling. Some parts were even used for crafts. The old glass refractors can be used as pots and the ceramic arc tubes can be used for sharpening knifes. Representatives of Environmental Assessment and Liabilities at The City of Calgary presented a paper on our environmental monitoring program at the International Association of Impact Assessment Conference in Vancouver in 2004.

Wouldn’t it have been more economical to simply replace the old lights as they burned out instead of doing them all at once?

No. If we had done this project by attrition it would have taken about eight or ten years, and it would have been very hard to manage. The City replaced the lamps in the old luminaires on a 5-year cycle. With the retrofit project, the whole luminaire, including the lamp is replaced. As such, the group relamping is not being done during the retrofit, which is resulting in increased savings. In addition to reducing light pollution and glare, The City also wanted to reduce the wattage of residential streetlights in order to reduce electricity consumption. The new streetlights will save The City approximately $1.7 million a year in energy costs once the project is complete. These savings ensure that the project pays for itself. Reduced energy consumption also results in reduced emissions from gas and coal-burning generators. When the EnviroSmart Streetlights project is complete, CO2 emissions will be reduced by as much as 19,000 tons a year.

How Can We Protect the Night Sky?

You have probably moved to Custer County because of the beautiful environment–including the dark skies! The citizens here would like to preserve this environment. To that and Dark Skies (a Wet Mountain Valley volunteer organization) would like to inform you of the various issues concerning outdoor lighting to be considered when building or adding onto your home or place of business.

Good lighting does its intended job well and with minimum adverse impact to the environment. One way to accomplish good lighting is to use “fully shielded” lights, where no light is emitted above the horizontal. Shielding lights controls which areas are illuminated and prevents unnecessary light escaping upwards. But some modern lighting systems illuminate areas to a level 100 times as bright as the full moon! Too bright an area on the ground can cause Glare where people or objects in the shadows become invisible.

Careful positioning of light fixtures will also maximize the effectiveness of the illumination. Fixtures should be positioned to give adequate uniformity of the illuminated area. A few bright fixtures (or ones that are too low to the ground) can often create bright “hot spots” that make the areas in between seem dark. Even well shielded fixtures placed on tall poles on a property boundary can cast a lot of light onto neighboring properties. This “light trespass” greatly reduces and invades privacy and is difficult to resolve after the installation is complete.

In order to reduce both operating costs and save energy, use high efficiency lights such as LEDs with a color temperature of 2,700k – 3,000K, which will create a natural warm tone. Placing lights on timers so they are functioning only when necessary is also a helpful alternative to the electric eye type fixtures which are on continuously from dark to dawn, or use motion detectors on the security lights.

Good lighting means that we save energy and money, and we avoid hassles. A quality lighting job makes a “good neighbor”… and we all have a safer and more secure nighttime environment. Always remember that lighting should benefit people. Controlled, effective, efficient lighting at a home or business will enhance the beauty, while providing visibility, safety, and security. Then we ALL can continue to look up and see the Milky Way!!


To what might be its everlasting credit, the New Mexico Legislature in 1999 enacted the Night Sky Protection Act. It recognized not just the beauty of our state’s skies, but their economic value as well.

For more than a century, travelers from the East’s smudged and glaring atmosphere have raved not only about the blue above them in the daylight, but also about the moon, the stars, the planets so bright above them at night.

New Mexico, many of them concluded, is worth many a return visit — maybe a change of residence …
But the more people who came here, the more lights they plugged in — and the harder it became to enjoy a renowned resource. The tourism industry, not to mention economic development so often spun from visits to our state, stood to take a hit if New Mexico became indistinguishable from the brightly lighted sprawl of Dallas-Forth Worth, Phoenix-Mesa or Los Angeles-San Diego.

An effort led in the House of Representatives by Democrat Rhonda King of Stanley and Republican Pauline Gubbels of Albuquerque struck a nerve with fellow legislators on both sides of the aisle. Night-sky protection gained a statutory foothold. Aimed at outdoor-lighting fixtures, the law amounted mainly to guidelines for putting hoods on bulbs, and for replacing mercury-vapor lights with effective, but less glary bulbs. Fixtures would have to be aimed below horizontal.

The law, sensibly enough, exempted lights of less than 150 watts, although the New Mexico Heritage Preservation Alliance, a major advocate of the law, campaigned for voluntary shielding of porchlights and the like. The Night Sky Protection Act was a good start — but more was, and still is, needed.

This week, the state Senate approved, 32-3, a bill providing that the state “shall enforce” the law — instead of the “may enforce” language in the original law. It’s an overdue step — and we salute Sen. John Arthur Smith of Deming for shepherding the proposal through the Senate. We urge the House to approve it, too — but something else is needed: money. The Legislature should make an appropriation to the state Construction Industries Division giving it the people it needs to review building plans and be sure that the lighting for new construction complies with the law. Had CID been given the support it needs, perhaps such recent projects as the Pojoaque fire station would have come with proper lighting.

As an official building, it should be an example for others; same for a new Motor Vehicle Division office in Deming, which went up with broadcast-glare fixtures when downward-guided ones could have been used. As more and more buildings go up around the state, they’ll sport lots of lighting fixtures. The time to regulate them is before they’re bolted on. Night-sky protection, for all its urgency, was conceded by even its most optimistic supporters to be a gradual process — but it shouldn’t be a one-step-forward, two-steps-back affair.

Building-supply manufacturers have developed all kinds of creative equipment for dimming and directing light. When old fixtures are replaced, that’s what should be used. As for new construction, ni hablar. Encourage your legislators to strengthen the Night Sky Protection Act.