The coming revolution in LED lighting

led lighting
Credit: CC0 Public Domain

A revolution in energy-efficient, environmentally-sound, and powerfully-flexible lighting is coming to businesses and homes, according to a paper in latest special energy issue of Optics Express, the Optical Society's (OSA) open-access journal.

The paper envisions the future of lighting—a future with widespread use of (LEDs), which offer a number of obvious and subtle advantages over traditional light bulbs.

"We are at the verge of a revolution," says the paper's senior author E. Fred Schubert, a professor of electrical engineering and physics at Rensselaer Polytechnic Institute in Troy, NY. "There are tremendous opportunities that open up with LED lighting."

LEDs are more rugged, resembling something closer to hard plastic than thin glass. They are also more environmentally sound, since their manufacture does not require toxic substances such as mercury.

As an alternative to the traditional incandescent light bulb, LED lights provide significant energy savings. They can be 2,000 percent more efficient than conventional light bulbs and 500 percent more efficient than compact fluorescent bulbs. Schubert predicts that widespread use of LEDs over the course of 10 years would save more than $1 trillion in , eliminate the need for nearly a billion barrels of oil over 10 years, and lead to a substantial reduction in emissions of carbon dioxide, the most common greenhouse gas.

All of these advantages make LEDs a good replacement light source, says Schubert, adding that this is why there has been a tremendous recent expansion of the LED industry, which is growing by double-digit rates. However, he adds, the true potential of LED lighting lies in their ability to transform—rather than simply replace—lighting technology.

"Replacement is fine," says Schubert. "But we must look beyond the replacement paradigm to see the true benefits of LED lights." Schubert envisions a day when light switches give way to light switchboards that control not only the brightness of a light, but its color temperature and hue. Light spectra could be custom-tailored for all wavelengths, accurately matching the sun's light qualities and vary these characteristics according to the time of day, for instance. This could revolutionize indoor agriculture and help night-shift workers and people who are jet-lagged. The use of polarized light from LEDs could also improve computer displays and lower the glare from car headlights.

In his article, Schubert lays out how such future, "smart" sources, can harness the huge potential of LEDs.


Explore further

The Green (and blue, red, and white) lights of the future

More information: Jong Kyu Kim et al. Transcending the replacement paradigm of solid-state lighting, Optics Express (2008). DOI: 10.1364/OE.16.021835
Journal information: Optics Express

Citation: The coming revolution in LED lighting (2019, February 28) retrieved 24 April 2019 from https://phys.org/news/2019-02-revolution.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
299 shares

Feedback to editors

User comments

Feb 28, 2019
I replaced all my home lighting with LEDs about 3 years ago. Not changed one since, and use less energy if I have all of them on than I did with previously having only one incandescent on. No brainer.

Feb 28, 2019
I replaced all my home lighting with LEDs about 3 years ago.

Yeah. I was a bit surprised when I read "we are on the verge of a revolution".
Hello? LEDs are already installed basically everywhere I look.

Feb 28, 2019
Finding the desired color balance, efficiency and price point is not obvious just yet as anyone who has shopped for the ubiquitous 4 foot shop lighting can attest to. One reads about new LEDs with a CRI of 98 and an efficiency of 200 lumen per watt with very low blue light output but then try finding a fixture for sale anywhere.

Feb 28, 2019
Well the LEDs might last a long time but the ballasts do not. I have had quit of few bulbs that stopped working. Also they will fail much more quickly in an enclosed fixture.

Feb 28, 2019
Incandescent light bulbs do emit a lot of heat, so that the temperature in a tiny room such as a guest bathroom with 2 of such light bulbs could warm a few degrees if the door is kept closed - but not in a large room. And their life expectancy is too short.
So LED is now the bulb of choice - longer lasting with not too many downsides.
Perhaps third-world countries will follow suit before long - at least those who are tied to the electric grid.

Feb 28, 2019
I'm laughing at all the MAGA Hatters that purchased and hoarded thousands of wasteful incandescent bulbs to protect their 'Freedumb".

Clueless Morons.

Feb 28, 2019
LEDs are an art form

There every where
and to think the common market (united states of Europe) banned incandescent bulbs
what a waste of common market membership fees
we think technology is in the latest cellular phone
the OPPO with its 10x optical zoom and flexible screen
could well be using LEDs
one of the biggest revolutions
is
the light bulb
LEDs are surpassing traditional bulbs with their superior light
because
without light bulbs
we would still be in the dark ages literally
when the sun sets every evening
LEDs have transformed city architecture and display lighting
the London Eye puts LEDs to good use at the setting of the sun
but
these innocuous little bulbs, in their quite brilliant revolution
have
transformed cycle lighting
that
gone are the days of oil bike lights with a wick
these
little bulbs on their handle bars
put out 4,500 Lumens
that's
More than an Audio on full beam

Feb 28, 2019
MR
Well the LEDs might last a long time but the ballasts do not
LED's do not require a ballast. https://sitlersle...-bypass/ Replacing a fluorescent tube bulbs with LED's is dumb. You should either re-wire the ballast out of the circuit - or better - buy a dedicated fixture. I just replaced some shop lights - with dedicated LED's. Whole fixture was about $25 - draws a total of 40watts - should lats 50,000 hours.

Mar 01, 2019
While the promises are by far exaggerated, if this article had been published at least 12 years ago, I would have said "well done, good forecast". - But today, as almost all lighting is meanwhile LEDs?
Unfortunately the industry made the same mistake as ever before. As business is a bitch, they always forget to be honest and realistic: The promise always too much. The figures above are way too high as they even exceed the physically possible limits! Finally the products are always lagging behind expectations:
david_king for example got tricked by these promises: You can either have LEDs with 200lm/W or CRI98, but not both at the same time.
In regards to energy savings is just to say that in many cases there will be almost none (globally seen) until energy prices are increased reasonably! It's about the human factor: Instead of saving energy the number and brightness of installation is increased. ...

Mar 01, 2019
"LED's do not require a ballast."

Onions whether it is called a driver or a ballast , both are acceptable, is immaterial. LEDs need to convert 120v AC into low voltage DC in order to operate. I find that these circuits are failure prone in normal use.

Mar 01, 2019
Onions whether it is called a driver or a ballast
I gave you a link MR - that pointed out clearly that LED's do not need a ballast. A ballast is a specific piece of equipment. Here - have someone read this to you - you may learn something - https://www.lrc.r...last.asp

So again - LED's do not need a ballast. Again - as shown in the link I gave you - if you replace a fluorescent tube with an LED - you need to take the ballast out of the circuit.

Mar 01, 2019
Good God Onions you sure are stubborn. LEDs have a built in driver or ballast and yes to have a florescent ballast in the circuit also is a waste of power and efficiency.

Mar 01, 2019
https://www.light...e%20Site

This is a led driver for large lamps. Small consumer led bulbs have it built into the base like a florescent.

Mar 02, 2019
Good God Onions you sure are stubborn. LEDs have a built in driver or ballast
Maybe stubborn - but I am right. LED lights do not need a ballast. And you said -
Well the LEDs might last a long time but the ballasts do not
So I pointed out that LED lights do not need a ballast - and I have demonstrated that multiple times. Here is another link for you - https://blog.1000...d-driver
Relevant point -
LED drivers (also known as LED power supplies) are similar to ballasts for fluorescent lamps or transformers for low-voltage bulbs: they provide LEDs with the correct power supply to function and perform at their best.
Do you know what the word 'similar' means? But what I am really trying to point out - is that you are not very careful with your words. That carries over to many of your comments. Just suggesting you learn to be more careful.

Mar 02, 2019
@MR doesn't know enough electronics to know the difference between a ballast and a power supply.

You're arguing with a dog about relativity, @greenos.

Mar 02, 2019
@greenonions1 @mr166 An electrical ballast is a device placed in line with the load to limit the amount of current in an electrical circuit. A current limiting resistor placed in series to an LED is often referred to as a ballast resistor.

Mar 02, 2019
@Skalamanga - an LED does not require a ballast. https://insights....ependent
Incandescents don't need ballasts...The same goes for LEDs, technically, except many LEDs are also made to work off of a ballast
The reason some LEDs are made to work with a ballast - is so that they can be 'plug and played' with existing fixtures (don't need to replace the old fixture). HOWEVER - if the ballast burns out - it is smarter to now wire the ballast out of the circuit. I have replaced a number of fluorescent fixtures - and it is better to buy a new fixture - that will last you 50,000 hours. When you are talking about lighting - a ballast is not just a device to limit the current.
The ballast regulates AC power to the electrodes. Older lamps used a starter to get the lamp going. Modern lamps use pulse start which is done by components within the ballast
http://edisontechcenter.org/Fluorescent.html

Mar 02, 2019
@greenonions1 There is no point reiterating the points you already made, we're way past that.

The term 'ballast' is used to describe a mechanism that provides stabilisation to its host. This may be a ship, balloon, chemical reaction, electrical circuit or component, or a multitude of other devices or processes.

The simple fact is that the term 'ballast' is commonly used to describe the resistor added in series to an LED, and that in this context, it is a perfectly valid description.

Mar 02, 2019
The simple fact is that the term 'ballast' is commonly used to describe the resistor added in series to an LED, and that in this context, it is a perfectly valid description
Ahhhhh - so you are saying that MR is correct when stating
Well the LEDs might last a long time but the ballasts do not
that MR was referring to the resistor that is added in series to an LED. And that these resistors do not last long. Where as the LED itself does last a long time. Could you perhaps supply some links that would support this assertion of resistors that fail before the actual LED's fail? Thanks...

Mar 02, 2019
Onions the ballast/driver in a LED bulb is a constant current power supply not a resistor. The function is very similar to an electronic ballast in a florescent fixture. Both provide current limiting to the lamps and both have semiconductor components that are sensitive to excess heat. Filament light bulbs are different in that they can be connected directly to the rated voltage with out drawing too much current.

Mar 03, 2019
Both provide current limiting to the lamps
No they don't. The driver in an LED light is a power supply. There is no need for a current limiter. The LED draws the current it needs - and no more. With a fluoresctent bulb - the resistance of the bulb goes down - as the gas becomes charged - and the ballast compensates for this - and acts as a current limiter.
As current forms an arc through the lamp, it ionizes a higher percent of gas molecules. The more molecules are ionized, the lower the resistance of the gas. We know that no resistance will equal a short. So without the ballast to control the current, current would rise so high that the lamp would melt and destroy itself
http://edisontech...ent.html

Interesting right? No matter how many times I show you that you are wrong - AND provide LINKS to support what I show you -- you can't back down - and can't ever supply links. Can you say Dunning Kruger?

Mar 03, 2019
A power supply is not a ballast. It trades off voltage for power. A ballast resistor cannot do this. In addition, power supplies for LED lighting convert AC to DC. A ballast resistor cannot do this either. A diode network is required to rectify the current.

Mar 03, 2019
@mr166 @greenonions1 A led driver is a combination of a power supply, a power converter and a control mechanism. This has no relation to a ballast whatsoever. This is the part that commonly fails, usually due to cheap components, bad design, incorrect specification or improper placement.

The ballast resistor for an led is connected very closely to the led itself and is selected by determining the forward voltage of the led and rating this against the input voltage. Without this, the led will draw too much current and eventually overheat and burn out. This is a resistive ballast and is highly unlikely to fail.

The ballast of a fluorescent light fixture is a reactive ballast and is what the term is describing when replacing a tube with an led strip.

An incandescent lamp is technically it's own ballast as it's self regulating. As it gets hotter, its resistance increases, limiting the current it will draw.

Mar 03, 2019
The resistor connected to an LED to limit the current isn't a "ballast resistor." It's a limiting resistor.

On edit: according to Wikipedia I'm wrong. Any limiting resistive or reactive component can serve as a ballast.

Mar 03, 2019
Skalamanga
This has no relation to a ballast whatsoever
Wow - why have we gone around and around in circles - to come to the same agreement - which is that MR's statement
Well the LEDs might last a long time but the ballasts do not
is bollocks. LED's do not require a ballast (meaning a very specific piece of equipment - designed to control the current and voltage - for a fluorescent tube.) Fluorescents need a ballast for a couple of reasons - 1. to supply a higher voltage to get the bulb started 2. to limit the current - so the bulbs don't self destruct. I have supplied links that discuss this in detail.

Dunning Kruger does not understand stuff. So what? Except Dunning Kruger has brought us Trump (sorry to be U.S. centric) - and may bring us the end of the human race - if we continue to deny the reality of climate change.

Mar 03, 2019
So again - LED's do not need a ballast
Retard OCD greengotts thinks semantics is victory. No wonder she cant think clearly.

Mar 03, 2019
@greenos, @Skala is right- technically the current-limiting resistor on an LED is a ballast.

However, you are correct that @MR's statement is ridiculous. A simple resistor will last much longer than an LED.

You're also correct that fluorescent ballasts are essentially different from LED ballasts; fluorescent ballasts are inductive, whereas the ballast resistor in an LED circuit is just a simple resistor, usually made from metal film and essentially indestructible unless it experiences overcurrent and burns.

Mar 03, 2019
Onions LEDs need current limiting because they are forward biased diodes. Once the junction voltage is exceeded current rises exponentially and a very small increase in voltage from that point results in a huge destructive increase in current.

Mar 03, 2019
Da the ballasts in a LED light bulbs are not just simple resisters because that would waste too much power and create too much heat. They are constant current switching power supplies that have heat sensitive electronics in them, thus the failures in enclosed spaces.Yes, if you are powering one low power led as an indicator light a resistor is adequate and will last longer than the led.

Mar 03, 2019
I have switchers that are 25 years old and work like a firehose: turn it on, power comes out whadda ya want.

Think them LEDs will last that long?

Mar 03, 2019
Otto
Retard OCD greengotts thinks semantics is victory
Well - I do think that being accurate in what you say - is important. That is how you spot (for example) a racist. They say racist things - and then pretend they never said them. Just saying.

Mar 03, 2019
Onions LEDs need current limiting
No they don't NEED one. I have built multiple LED systems for growing plants - and just used a regular 12 V power supply. Now - I never took the supply apart to see if there was a current limiting resistor in there - but here is a good discussion of the topic - https://resources...r-supply
many companies are choosing to use a regular switching power supply and are omitting current limiting resistors in their LED installations
But hey - I am happy to concede that LED's should use a current limiting resistor as best practice (as per article). But you said
Well the LEDs might last a long time but the ballasts do not
Which is bollocks - and of course you NEVER bother to supply any links to your sources. LED's do not require a ballast (the thing that goes on a fluorescent light fixture). Period.

Mar 03, 2019
Well - I do think that being accurate in what you say - is important
Well any neurotic anal retentive would say this. I rest my case.

Mar 03, 2019
Pretty well sussed you, @Blotto the Bigot.

Mar 04, 2019
I have learned to wait until at least the third or fourth generation of any new technology before jumping on the bandwagon. Simply because of the initial high cost.
The trail blazers do stand a chance of making lots of money if they are innovators but I'm not one of those so as a consumer I just wait till the problems are sorted out.

Mar 04, 2019
@FreddyJoe thinks jebus makes energy.

Back to your sister/girlfriend, the book about the super magic daddy in the sky by the drunk stone age sheepherders, and your trashbarrel fire at the trailerpark, @FreddyJoe.

Mar 04, 2019
"Which is bollocks - and of course you NEVER bother to supply any links to your sources. LED's do not require a ballast (the thing that goes on a fluorescent light fixture). Period."

Let me get this straight Onions you are claiming that you are correct because LEDs do not require the exact same ballast as a florescent light. Part of being an intelligent person is having the ability admit defeat and shut up when one has made an error.

Mar 04, 2019
https://www.ecse....LEDs.pdf

Onions I really don't expect you to understand this paper but this is the proof that LEDs need a ballast.

Mar 04, 2019
proof that LEDs need a ballast
No it is not. It is proof that good practice for LED's is the use of a current limiting resistor. I have built LED systems for growing - that do not have a ballast - they simply have a power supply. One link I provided above - stated clearly - that many companies are not using a current limiting resistor - although the paper said that doing so may shorten the life of the led - if the power supply used is not providing consistent enough voltage.

HOWEVER - the bollocks I am calling you on is with this statement.
Well the LEDs might last a long time but the ballasts do not
And nowhere have you supplied a link to support the assertion that the current limiting resistors on the LED's do not last as long as the bulbs. I have just bought several LED shop lights - they are rated at 50,000 hours.

So what does this silly spat have to do with anything? cont.

Mar 04, 2019
cont. I am simply interested in the issue of lies. What I am seeing is the conservatives - like yourself - spamming the internet with lies. On one other thread right now - you are claiming that renewables cannot run our world. That's a lie. So I am just playing with challenging you - to see how you react. And you seem to react like every conservative I meet in real life. When challenged with the lies you seem compelled to spit all over the internet - you duck and weave - and never actually take responsibility. And so what? Well - I don't know if we are going to survive the current environmental havoc we are creating. Doing so will involve pulling out all the stops - and working hard together. We will have to understand the strange psychology of delusional people - who are compelled to spit lies at everyone. So just an interesting process for me.

Mar 04, 2019
because LEDs do not require the exact same ballast as a florescent light
No - because you made this statment
Well the LEDs might last a long time but the ballasts do not
And no matter how many times you are pressed - you did not provide any support. In other words - you pulled something out of your ass - and then pretend you never said it - when called on you bollocks. Remember when you accused me of being a member of the 90%. I asked you what you meant - and you said 90% of teachers support Dems. I showed you a link contradicting that - and asked you for support for you 90% assertion. Crickets. Same with the 1 Kwh to 7Kwh ratio for batteries - that you never would support. So I am just playing around with a bit of extra time (school is cancelled today) - and wondering about the weird psychology of internet/Republican liars.

Mar 04, 2019
Pretty well sussed you, @Blotto the Bigot
? Is this an actual sentence with actual meaning in it? I must defer to my brick-in-ass colleague who reminds us to remember that
being accurate in what you say - is important
Here here... or is it hear hear? Aw who cares-

Mar 04, 2019
I must defer to my brick-in-ass colleague
I have no idea what that means Otto. I googled it - and couldn't come up with anything that would really clue me in to your meaning. Perhaps you could enlighten us - in the spirit of being careful with language...

Mar 05, 2019
Odd. The phrase 'hes got a brick up his ass' connoting a certain posture and gait and attitude seems to be a regional colloquialism.

But that's what you got.

Mar 05, 2019
Never heard the expression Otto - and google does not seem to have heard of it either. So now you're commenting on other peoples 'posture, and gait, and attitude.' Pretty dumb right?

Mar 07, 2019
This comment has been removed by a moderator.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more