
Detroit’s LED streetlights going dark after a few years - danso
https://www.detroitnews.com/story/news/local/detroit-city/2019/05/07/detroits-led-streetlights-going-dark-after-few-years/3650465002/
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dreamcompiler
The dirty secret of LED lighting is that while LEDs themselves last a long
time, they only do so in the presence of good power supply design and good
thermal design. If you cut corners on the power supply or thermal management,
LEDs will burn out much quicker than older lighting technologies. The majority
of consumer-grade LED "bulbs" available today are shitty on both counts,
AFAICT.

~~~
taneq
> If you cut corners on the power supply or thermal management, LEDs will burn
> out much quicker than older lighting technologies

Really? As an anecdatum, I replaced most of the lights in our house with cheap
LED globes a few years ago and so far not a single one has failed. Maybe I'm
just lucky. CCFL lamps, however, have been terrible while using 3x the power.

~~~
RRWagner
My anecdatum is that I bought CREE LED replacements about five years ago and
I've had to replace more than a few already as they have started failing.

~~~
xbmcuser
Led tech has improved in the last 5 years. So experience with led of 5 years
ago might no be the same as led of today or even 3 years ago. My boss
converted his house to led 5-6 years ago I did around 2 years ago. We had a
huge discussion about it when our office was being renovated recently. He had
to replace about half in the first couple of years of install I have had to
replace none so far.

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jedberg
I still don't understand this trend of replacing the sodium lamps with LED.
The sodium lamps use roughly the same amount of energy, cast a light quality
that is better for both humans and animals, and are already there, saving a
bunch of money in doing replacements.

Why are all these cities undertaking huge renovations to go to LEDs?

~~~
wnevets
>The sodium lamps use roughly the same amount of energy

That doesn't sound right, source?

edit: [https://www.stouchlighting.com/blog/led-vs-hps-lps-high-
and-...](https://www.stouchlighting.com/blog/led-vs-hps-lps-high-and-low-
pressure-sodium)

Why would LEDs put Sodium vapor lights out of business? Sodium lamps have the
worst color rendering of any bulb. They produce a dark yellow glow which is
generally a very low quality light. Additionally, there are serious waste
disposal issues with sodium lamps. In particular, they have been known to
start fires in the event that the lamp is broken and the sodium metal is
exposed. The sodium can catch fire even in the event that the lamp is broken
on the ground. For this reason it is safest to break sodium lights under water
and then to subsequently dispose of the destroyed bulb. Lastly, HPS and LPS
lights are monochromatic, so they can mess with your color vision if you look
at them for an extended period of time.

Perhaps more importantly, in the last few years LED efficiency has surpassed
that of even LPS and HPS lights and its efficiency improvements are
progressing at a much more rapid rate. The largest selling point of LPS and
HPS lights is the cheap selling price, the high energy efficiency (low
operating costs), and the relatively long lifespan. LPS and HPS still retain
these advantages over most conventional bulbs but they lose on all three
counts to LEDs. In some areas (e.g. lifespan) they are drastically inferior to
LEDs. The extremely low maintenance and replacement costs with LEDs is
actually a major cost benefit over the long term. LED lifespan can be greater
than 100,000 hours (more than four times that of LPS or HPS). Having to
purchase one bulb versus 3 or 4 bulbs over the course of time is a significant
selling point for LEDs. The bottom line is that having lost their traditional
advantage of being the most energy efficient bulb on the market, there’s very
little reason to use a sodium vapor light when LED lighting is available.

~~~
sp332
The low color quality, specifically the very warm hue, is a feature for
nighttime lighting. Blue light messes with sleep cycles of humans and animals.

The very narrow spectrum benefits astronomers because it's easy to filter out
light pollution from low-pressure sodium lamps.

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p1mrx
Warm white LEDs exist, with color quality exceeding that of sodium vapor in
every way, but cities often use blueish LEDs because they're cheaper and more
efficient.

Relevant Technology Connections video: [https://www.youtube.com/watch?v=wIC-
iGDTU40](https://www.youtube.com/watch?v=wIC-iGDTU40)

~~~
jacobolus
As a person who has spent a decade as an amateur student of human color
vision, let me state emphatically that “color quality” is a horrifically bad
criterion for choosing nighttime street lamps. Nobody should be trying to read
a book or critically evaluate photographs in the middle of the road at 3AM.

Street lamps should include as little short wavelength light as possible and
should otherwise be as even (this means: use more lamps spaced closer and
placed at lower height, diffused and shielded from the side) and dim as
possible, so as to avoid causing distracting glare in people’s peripheral
vision, and avoid causing high contrast between areas directly under the lamps
and areas in shadow. Human vision is amazingly good at adapting to very low
light levels. After adaptation, humans can navigate the environment by e.g.
starlight, but at any rate can see just fine under sodium lamps.

But the way cities roll out LED street lighting is to put a small number of
widely spaced very intense blue lamps high up in the air, not diffused and
with little shielding from the side.

Every parameter has been optimized (pessimized?) for blasting away people’s
night vision and causing enough glare to make seeing into the shadows all but
impossible.

Extremely low color temperature LEDs would be fine, but don’t really have any
especially great advantage over sodium lamps. (Except maybe for getting some
government subsidy money?)

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umvi
LEDs last a long time. Apparently some other critical supporting component
inside LED bulbs fail within 1-2 years.

Nearly every brand I've tried started flickering or dimming or failing in some
way after 2 years of use despite the box touting 10+ years of life.
Disappointing to say the least.

~~~
Reason077
I’ve had excellent results with Phillips LED bulbs. Been using various models
for years and I don’t think a single one has failed.

Also, the IKEA ones seem fine.

~~~
geomark
Same here. Multiple other brands have high failure rates in a short amount of
time. In my case I think it is because of the poor quality mains power which
suffers frequent spikes and outages during storms. Philips seems more robust
to those conditions. They used to cost a good deal more but have come down to
price parity with other brands.

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nerdkid93
I really hope for Detroit's benefit that the warranty was provided by some
underwriter, and not from Leotek itself.

~~~
rwallace
Why? Is there a reason Leotek might be able to ignore a court judgment, or
unable to pay?

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tomohawk
The dimming seems like more of a feature to me. The over bright / sharp led
street lights are a hazard. Same with the led lights on emergency and other
vehicles.

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bluedino
LED streetlights are terrible. Sure, they look nice, but they don't provide
much light.

They're always underspecced so you get a little square of light directly under
the street lamp, but that's about it. Looks like early 3D videogame lighting.

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nullc
Cities all over the country getting scammed into replacing their proven
discharge lamp streelights for LEDs on the basis of TCO analysis that is
predicated on false reliability figures. I'm sure some consulting firm is
laughing all the way to the bank. Oh well, more cheap LPS fixtures for me...

I was recently in LA and drove down to long beach, every other streetlight was
dead.

Maybe by the time they figure out what a disaster this is and have to redo it
all, they'll do a better job at cutting out the light pollution.

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RickJWagner
What a nightmare. Detroit installs LEDs in the hopes of saving money and
power, then ends up with a bunch of lights that need to be replaced. (Also,
lots of more trash to deal with.)

Ugh. I hope the right long-term changes happen where they are needed.

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cr0sh
This almost sounds like a case where the city cheaped out (maybe the budget
just wasn't there?), and went with a third tier supplier.

I noticed the article noted that units supplied from Cree, used in other areas
of the country, are performing up to standards and not dying like the ones in
Detroit from Leotek.

To me, it's one thing if you're a hobbyist or something looking to save some
bucks so you buy cheap LEDs drop shipped from China via Ali Express, from some
rando vendor and manufacturer. If one or more die, usually it's not a big
deal.

But if you're building a product, or installing something commercially or at a
government level, you should do yourself a favor and not go for the lowest
cost. While I'm sure Cree LEDs are probably manufactured in China, too, they
are likely made to a much different standard.

For all we know, Leotek is using relabeled parts that are marginal or failed
to pass QA inspections at other manufacturers, but they got a great deal on
barrels of rejected LEDs, and decided to go into the commercial light
manufacturing business.

I honestly don't know who or what the company is. What I do know is the name
"Cree" and their quality (which also comes with a hefty $$$ price/cost) - but
"Leotek" sounds like a company you'd find in a random search on Alibaba.

Maybe that's an unfair assessment; sometimes when ordering a large volume of
parts, you'll get entire batches that fail in the real world when they passed
QA fine...

~~~
village-idiot
What’s interesting is that Berkeley used some LEDs from the same company, and
I assume they’re not facing the same budgetary pressure that Detroit was.

~~~
mc32
The bay bridge project could have sourced the main steel parts for the eastern
span replacement from US manufacturers but chose to go with a foundry in
Shanghai. The USW, with all the pro-union talk in the Bay Area, cheap was
chosen. Money talks.

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ProfessorLayton
I don't know if cheap is the right word for a project with a _2,500%_ cost
overrun[1]

[1]
[https://en.wikipedia.org/wiki/San_Francisco–Oakland_Bay_Brid...](https://en.wikipedia.org/wiki/San_Francisco–Oakland_Bay_Bridge)

