Monday, May 22nd 2023

Why Are the Streetlights Turning Purple in San Miguel

Written by

Rafael Bracho

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Why Are the Streetlights Turning Purple in San Miguel

If you’re living in San Miguel, then you’ve likely come across the purple lights. That’s right. Streetlights in San Miguel have been turning purple one by one. No, this isn’t part of some Mexican celebration. It’s a far more international occurrence.

In this article, Expat Insurance investigates the mystery of the purple streetlights, and what San Miguel is doing about it.

Streetlights Are Turning Purple Over the World

Why Are the Streetlights Turning Purple in San Miguel

It hasn’t just happened in San Miguel de Allende; it isn’t even isolated to Mexico. Numerous American states have seen their streetlights turn blue or purple, including: North Carolina, New Mexico, Texas, Wisconsin, New York, and California. Not only that, Canadian cities like Vancouver have noticed their streetlights turning violet. It’s even been spotted across the Atlantic in Ireland.

But what’s causing this curious phenomenon?

Installing LEDs In Our Cities

Why Are the Streetlights Turning Purple in San Miguel

At the start of the 21st century, vapor light bulbs were the new rage—fluorescent tubes, mercury vapor, and most popular: sodium vapor. However, by the late 2000s, sodium vapor lights were slowly being replaced by the new LED light bulbs that were fresh on the market.

LEDs are far more efficient than incandescent bulbs. They turn electricity directly into photons, which is more cost effective. These are cheaper to manufacture and operate, and they even last longer. Thus, switching to LEDs was a no-brainer.

Or was it? What went wrong?

These white LEDs operate at 4,000K which is about as bright as the glow of a high-end sports car’s headlights. These lights were a cooler white than the dreamy orange glow of sodium vapor lights, and they had their detractors at first, but people got used to them. But, as Sandy Isenstadt—historian of art and architecture at the University of Delaware—points out, “The introduction of every new lighting technology caused a lot of consternation until people got used to it.”

It seemed to be a miracle product. the World Bank even reported that LED lights had “unburdened cities” around the world. And then they turned purple. . .

The Cause of Streetlights Turning Purple

Why Are the Streetlights Turning Purple in San Miguel

It occurred almost overnight, the streets turned purple in cities all over the continent. It seemed like an epidemic, though in reality, purple lights represent only 1% of the LED streetlights that have been installed.

We’ve had red and green LED lights since the middle of the 20th century, but blue was a bit of a challenge. The high frequency of the blue spectrum proved to be a challenge to replicate in LED form until a Japanese scientist named Shuji Nakamura figured it out (and then won the Nobel Prize for it in 2014). Having a blue LED light opened all kinds of doors in technology, from flat-screen LED monitors to Blu-Ray technology. It also made for cheaper streetlights.

Previously, you needed the green and red lights to make white. But now with blue LED lights, you don't need the other ones. All you need is a phosphor lens of glass and ceramic—which mixes the blue with yellow, giving us the illusion of white light.

Unfortunately, the phosphate coating on the LED lights is deteriorating over time. As this outer yellow covering weakens, in a process known as “delamination”, the yellow becomes less intense—mixing with the blue LED to create a funky violet hue.

But what’s causing this delamination? The most likely culprit is heat exposure.

As it turns out, the phosphor layer surrounding an LED light is very sensitive to changes in temperature. That doesn’t only mean changes in climate—like the changes in temperature between San Miguel’s hot days and frigid nights—but also any defect in the surrounding glass and ceramic covering can cause the LED light to put out heat. The phosphor coating ends up curling and peeling away from the blue LED light causing it to let more of the natural blue light shine through.

Some of this can also be laid at the feet of substandard production. Philips was the leading manufacturer of LED lights and they did a lot of testing at higher temperature, humidity, and voltage. Their bulbs could have easily lasted ten years.

Alas, Philips bulbs are some of the most expensive LED lights on the market. Instead, it appears that most of these purple cities seem to have gone with a company called Acuity Brands, which offered the contract at a lower price.

What Is Being Done About the Purple Lights?

Why Are the Streetlights Turning Purple in San Miguel

Well, as far as most cities in the United States are concerned, Acuity Brands are replacing the purple bulbs at no cost to the city. The lights are still under warranty. It should take about six months to have the defective bulbs replaced.

However, knowing Mexican infrastructure, I wouldn’t be surprised if we have to live with these purple lights substantially longer. Mexico isn’t known for its quick response in these types of matters. And sadly, Mexico may be a lower priority when American, European, and Canadian cities also look like a Prince concert.

If you absolutely hate the purple lights, then you should probably bring it up at the next city council meeting. Rest assured that the affected cities all plan to have the defective blue lights replaced. We’ll cover more about what’s being done in the next section.

What’s Being Done About the Purple Lights in San Miguel

Why Are the Streetlights Turning Purple in San Miguel

So far, 900 lights have experienced the “blue light” technical failure in San Miguel, and some locals are getting upset that the municipality hasn’t changed them. Residents’ main concern is that purple lights seem to be focal points for theft because of their poor lighting.

In April, 2019, Luis Alberto Villareal Garcia’s administration placed an order for 12,197 lights from a company named Consorcio Ingenieros de Guanajuato S.A de C.V—which means that in the past four years, 15% of the lights they provided have failed.

These lights are under a 10-year warranty, and from February 13th – 19th, they had a formal hearing with this “Consortium of Engineers of Guanajuato S.A. de C.V” to discuss the replacement of the defective products.

Mauricio Trejo Pureco, the mayor of San Miguel de Allende, released a social media post urging residents to report purple lights to the Public Services Department of San Miguel. However, so far, the authorities have done nothing to implement these changes.

Many People Like the Purple Lights

Why Are the Streetlights Turning Purple in San Miguel

Lots of people are liking the soft violet lights, both in Guanajuato and abroad. In the Dallas/Ft. Worth area, people have even asked about starting a petition to keep the purple lights. (They’re likely TCU fans.) That opinion seems to be shared with some residents in San Miguel.

“I like [the purple lights] because the color feels relaxing and reminds me of a resort-like atmosphere, especially walking around historic San Miguel de Allende,” said Chandler Hunt, a local resident. Though Chandler did add that, “In fact, sometimes when I am walking on the streets at night, I even drop my guard because I feel more relaxed like I am in a resort or amusement park.”

Personally, I’m inclined to agree. I find the lights less intrusive—and frankly rather beautiful. They seem to pair well with the dusty reds and golden yellows of San Miguel, giving the pueblo an ethereal quality. But that’s me. I know it’s not for everyone.

What do you think? We’d love to hear your opinions on the purple lights in San Miguel de Allende and elsewhere.

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