Unintended consequences of LEDs

[Rajiv]

Re: Unintended consequences of LEDs

The infrared leds would not have to use a lot of energy -- just sufficient that the ice sheet or snow melts just enough to slip off and fall to the ground -- and since snow and ice is a good insulator, it should be easy to accomplish.

[reallife]

Re: Unintended consequences of LEDs

This whole thread is just stupid! The posters are completely ignorant of the the Second Law. Please note that I didn't say: Second "Theory". Of course, any transformation of energy involves an increase in entropy. This is a simple concept that 'economists' simply disregard or are actually totally ignorant of.

From my undergraduate training, beginning with living in the dorms at the University of Illinois, in the early 1970s, I observed that the business majors didn't have the same rigorous mathematics education that was used to 'flunk' out the hard science majors. I knew lots of hard science majors who found refuge in 'Econ' and 'Business" when they couldn't make it in Engineering, Chemistry, Physics and Biology.

Sorry, but I find it just incomprehensible that previous posters don't seem to understand this simple physical process: When electrical energy is converted to light, some to the energy is 'lost' as heat which melts the snow and ice, the rest of the energy is used to generate light by the LED. The older incandescent bulbs lost 90% of the electrical energy as heat. Only 10% of the energy was successfully converted to light. Ninety percent was 'lost' as waste heat. The newer LEDS are better at converting electrical energy to light and result in less waste heat, so the snow and ice accumulates and blocks off the signals during bad weather. The newer LEDs cost less to operate because they waste less energy. More light per joule, less heat lost, less snow melted.

The reason society wants to use LEDs is because they are more efficient, that is they produce more light energy and less waste heat. This is simple thermodynamics. It is not that difficult to understand. Since LEDS are more efficient at producing light they produce less waste heat and the Red Stop Light freezes over. It is just stupid to think that we should produce less efficient light sources, to waste energy, to melt ice, in case of snow storms that occur maybe 2-3% of the days of the year.

This type of thread only reinforces my longstanding impression that economists are without any understanding of Thermodynamics, Physics, Chemistry, Biology, or Ecology. That is why they are called the dismal scientists. As I age I am becoming less tolerant of stupidity. Sorry....Economists are silly, stupid, scientifically and mathematically illiterate humanists masquerading as scientists. It is very unfortunate that society has entrusted economists with running our economic system. ;)

[Rajiv]

Re: Unintended consequences of LEDs

I think you are making an assumption that we do not understand the basic laws of physics -- having been a physics major, I do understand the laws of thermodynamics. I presume that you did not read my post in full -- the infrared leds do not come on until they are needed -- which may well be on 2-3 days a year (probably more like 2-3 weeks of the year, and for a very small time -- most likely 3-4 hours a year). The key thing would be to impart enough heat to the ice snow layer to allow it to slide off the traffic light. The control of the IR leds could well be done through an optic sensor that measures the backward reflections of the lights.

I hope that this clarifies any misunderstandings you may have on the prior postings.

And yes the traffic lights would become slightly less efficient in the process -- though presumably not by much - and they would become slightly more expensive to the municipalities concerned -- though also presumably, it would result in more "social good"

[ThePythonicCow]

Re: Unintended consequences of LEDs

This whole thread is just stupid!

The whole thread?? Every word of every post??

A tad pretentious are we?

I'm not going to go back and re-read the entire thread word for word to verify this, but as best as I can recall, the only thing incorrect in it so far was the one initial claim that LED's don't emit heat, which the rest of the thread has pretty much agreed was incorrect. Well, there might have been some confusions over just what LCD displays were as well.

May I suggest that next time you go off on a rant, you actually impose on yourself the discipline of quoting at least a representative sample of that to which you disagree, so that others (and even yourself) might be able to distinguish which claims are justified and which are perhaps just misreadings.

P.S. -- I don't recall anything in the Laws of Thermodynamics that mandates that conversion of energy from electrical current to light must emit heat, whereby "heat" I mean that portion of the electromagnetic spectrum that melts snow.

[renewable]

Re: Unintended consequences of LEDs

This type of thread only reinforces my longstanding impression that economists are without any understanding of Thermodynamics, Physics, Chemistry, Biology, or Ecology. That is why they are called the dismal scientists. As I age I am becoming less tolerant of stupidity. Sorry....Economists are silly, stupid, scientifically and mathematically illiterate humanists masquerading as scientists. It is very unfortunate that society has entrusted economists with running our economic system. ;)

I mostly agree with this. I used to visit iTulip a lot when it was focussed on economics, the speciality of most posters. Now the board is dominated by junk theories about evil climate scientist conspiracies, etc. it isn't worth bothering to visit as much.

If the LEDs don't produce enough heat to melt the snow, why don't they redesign the casing/surround of the traffic lights so that the light emitting part doesn't get covered in snow? I presume that the sunlight shade above the LEDs is creating a void for the snow to fill - if so, perhaps it could be covered with a cheap bit of transparent plastic at an angle that snow doesn't stick to.

[c1ue]

Re: Unintended consequences of LEDs

I think people are overly sensitive - this thread was posted purely to illustrate that there can be both good and bad consequences from new technology.

To be clear: I categorically state that LED traffic lights are NOT a bad thing.

I also categorically state that new technology as this example shows is rarely perfectly better. There definitely can be changes which fix this particular problem - but these changes impact the savings structure. Or put in other words - the salesman's arguments rarely encompass the whole picture.

This has nothing to do with any other subject.

[Master Shake]

Re: Unintended consequences of LEDs

In the meantime, the Department of Transportation uses big sticks to clean off the lights when it gets calls from drivers who complain.

That made me chuckle.

[flintlock]

Re: Unintended consequences of LEDs

This whole thread is just stupid! The posters are completely ignorant of the the Second Law. Please note that I didn't say: Second "Theory". Of course, any transformation of energy involves an increase in entropy. This is a simple concept that 'economists' simply disregard or are actually totally ignorant of.

From my undergraduate training, beginning with living in the dorms at the University of Illinois, in the early 1970s, I observed that the business majors didn't have the same rigorous mathematics education that was used to 'flunk' out the hard science majors. I knew lots of hard science majors who found refuge in 'Econ' and 'Business" when they couldn't make it in Engineering, Chemistry, Physics and Biology.

Your first paragraph I pretty much agree with. I found myself thinking, " I can't believe this thread is going on so long about something so simple". LEDs do give off heat, just significantly less than incandescent. Anyone who has ever tried to unscrew a incandescent bulb right after the switch was turned off can tell you it puts off a LOT more heat than an LED. But the thread is not useless. I learned a lot.

I also found the part in the article about the $40 cost for shrouds amusing when you consider the ten of thousands, if not hundreds, that your typical lights at intersections cost. $40 each too expensive?:rolleyes: Maybe its typical of some "science types' to try and find a high tech solution when a simple one already exists. Perhaps a business major like myself can figure that out quicker?

As for the second paragraph, the world needs all types. Those business majors who couldn't hack it in math? Often those are the guys we call "Boss". ( I get your point, but do you really see a bunch of scientists running things? We'd all be using $10,000 nuclear powered toilets and have remote controlled socks.)

For what it's worth, I've always thought Itulip is dominated by the science/math types, not the other way around. Most business types are too bored with this type of thread to give it a second look.

[Slimprofits]

Re: Unintended consequences of LEDs

When you see Wal*Mart and Costco lighting their big stores with LED's, that will be when LED's are actually more efficient. For now, they use mercury vapor or fluorescent.

And Metal Halide.