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>Energy-efficient lighting, such as LED bulbs, has become a popular solution to reduce energy consumption. However, it serves as a notable example of the Jevons

>Energy-efficient lighting, such as LED bulbs, has become a popular solution to reduce energy consumption. However, it serves as a notable example of the Jevons Paradox. While LEDs significantly lower the cost of lighting per unit, this reduction often leads to increased usage. For instance, people may install more lights in their homes or businesses, use them for longer durations, or adopt decorative and outdoor lighting more extensively. As a result, the total energy consumption for lighting has not decreased significantly despite the efficiency improvements. This felt false to me, LED bulbs are generally 10x more efficient, so the average number of lights would have had to increase 10 fold, and this is ignoring the savings from not having AC cool those other 50 watts a bulb that went to heat. So I took a look at the source, which doesn't actually have a source and just links to another white paper that claims light pollution increased, but is unclear about how much and due to what. Perhaps that whitepaper links to another whitepaper, but this is where I stopped. Kind of makes me question how often I blindly trust Wikipedia, though this point in particular is pretty minor.

blagie 2y ago
Your math is wrong: > This felt false to me, LED bulbs are generally 10x more efficient, so the average number of lights would have had to increase 10 fold, and this is ignoring the savings from not having AC cool those other 50 watts a bulb that went to heat. The first 5W also went into heat. Perhaps with the exception of light escaping through a window, *every* watt that goes into a lightbulb comes out as heat for your AC to cool. I would not be surprised if there were a 10x increase in use of lighting with LEDs. Not taking Wikipedia (or any source) on blind trust is always wise. More often than not, when you kick tires, you come back to folklore. It's fine for big things, but details are often wrong. Ditto for newspapers, for that matter.
- ApolloFortyNine 2y ago
  If a 5w bulb and a 60w bulb output the same amount of light, those 55w are being wasted elsewhere (heat). I said 50 because I was afraid someone would go 'ACTUALLY LED's only save 50-55w', I didn't expect someone to argue that the 5w led bulb is also outputting heat. You are of course right, 2.5w of that 5w is likely heat being cooled by the AC. >I would not be surprised if there were a 10x increase in use of lighting with LEDs. Quite frankly I don't care either way, I just wanted a source. I'm happy you feel that way though.
  - aurareturn 2y ago
    Quite frankly I don't care either way, I just wanted a source. I'm happy you feel that way though. This is the best write up I found for lighting source, efficiency, and consumption relationship. As a first step in looking at this, I’ve taken the data from the analysis and plotted it on a log scale. This shows clearly how consumption has increased as population and incomes (measured by per capita GDP) have risen and prices have fallen. The central role played by efficiency is indicated by the dashed line, which shows the number of kWh needed to produce a unit of light (1/efficiency). Comparing this with the solid blue price line showing price indicates that the 100 fold fall in price per unit of light in the 20th century was due to increased efficiency, mainly as electricity replaced gas. Yet demand rose strongly over the period, increasing more than 100 fold. This challenges the view that increases in efficiency translate into reductions in demand, and thus emissions. https://onclimatechangepolicydotorg.wordpress.com/low-carbon-technologies-section-overview/long-term-trends-in-lighting-efficiency-and-consumption/ https://onclimatechangepolicydotorg.wordpress.com/low-carbon...
- HarHarVeryFunny 2y ago
  > I would not be surprised if there were a 10x increase in use of lighting with LEDs. Has the average homeowner added more ceiling lights or lamps because of different bulbs? Has the average office added more lighting because of LEDs? Factories? In order for an overall 10x increase in usage, there needs to have been some MASSIVE new usage or expansion of lighting, somewhere, to make up for all of these enormous use cases (residential, commercial) where there was probably close to zero increase. So, do you have any pet theories ?!!
  - blagie 2y ago
    > Has the average homeowner added more ceiling lights or lamps because of different bulbs? As much as I appreciate the snark and sarcasm, at least where I live, the equivalent is happening. Old home and commercial construction would typically have one central light per room. Homes would have a single light fixture with 1-3 lightbulbs at the center of each ceiling and were pretty dimly lit. Commercial would be similar with fluorescents. You would turn it off when you left a room. New home and commercial construction has accent lighting all over the place, some turned on 24/7. Cabinets have under-cabinet-lights. Closets have closet lights. We have rows of LEDs lining all sorts of accents. If you compare 80's-style construction to 2020's-style, the amount of new light seems to be about that much of an increase.
    - deleted 2y ago
      [deleted]
    - aurareturn 2y ago
      Not to mention that in poor countries, the invention of LEDs could mean going from being able to afford electricity for 1 light in the house to 10 lights.
    - HarHarVeryFunny 2y ago
      I can accept that new construction may have more lighting, but nowhere near 10x, and certainly not 10x overall when you factor "legacy locations" where it is mostly just a bulb replacement.
woadwarrior01 2y ago
This is exactly the case. Anecdotally speaking, growing up in the 90s, I remember my parents adding lightbulbs and fluorescent tube lights to their shopping list every couple of months. We used to have a small stockpile of these in the pantry. Fast forward to today, the last time I bought lightbulbs for my house was over 5 years ago and that was to upgrade from regular led lamps to Philips hue.
- aurareturn 2y ago
  Not the case I’m observing. My sister just did a home remodeling and she added must have been 50 LED recessed lights in the ceiling. There are automated LED lights in the outdoor pathways, lights hanging on the balcony rails, lights under kitchen cabinets, lights inside closets, lights inside pantries, solar powered LEDs in backyard, etc. Her appliances also have more indicator lights than ever before. I’m not even counting the countless LED screens such as phones, iPads, TVs. In total, she may every well have 10x more lights than before the LED boom. Time Square in NYC was famous for having many lights and screens. Walk around any large Asian city in 2025 and they all look like time square with countless lights and screens. Thats said, there is a limit to lighting demand because we still need darkness to sleep. I think the upper bound for intelligence is far higher than LED lights.
  - Temporary_31337 2y ago
    Still it does not use as much electricity as the previous generation of light bulbs and she won’t be replacing them often. So from a perspective of the industry it’s not so good. The tech is better but there’s less sales / margins/ profits altogether.
    - aurareturn 2y ago
      Is this true? What were the revenues of lighting companies before compared to now? Do we count TV screen makers because they’re LEDs as well? I just watched Veritasium’s video on how LEDs were indented and the companies making LEDs saw exponential increase in revenue. https://youtu.be/AF8d72mA41M https://youtu.be/AF8d72mA41M Basic Google search tells me the lighting industry has experienced high growth due to the invention of LED lighting.
Ekaros 2y ago
I somewhat doubt there is now 10x light fixtures... Thus 10x the traditional bulbs. That seems rather large undertaking in most buildings. Sometimes I think it makes sense to stop and think what would 10x more of some items mean in practise.
quickthrowman 2y ago
LEDs are around 3-4x more efficient than fluorescent lamps, (1) 28W 2x4 LED fixture puts out around the same amount of light as (1) 4-lamp 2x4 fixture with (4) 28W fluorescent lamps, depending on the lumen output package on the LED fixture.
- mitthrowaway2 2y ago
  It's common to use incandescent bulbs as a baseline.
fragmede 2y ago
You're right. But it's wikipedia so I deleted the LED section and replaced it with a bit about cars.
aurareturn 2y ago
This felt false to me, LED bulbs are generally 10x more efficient, so the average number of lights would have had to increase 10 fold, and this is ignoring the savings from not having AC cool those other 50 watts a bulb that went to heat. Jevons Paradox does not state that there is a 1:1 relationship between efficiency increase and consumption. A 2x increase in efficiency does not always result in a 2x increase in consumption. With that said, it would not surprise me if there is a 10x increase in light sources (not total lumens) since LEDs.
- ahmeneeroe-v2 2y ago
  Yes, I don't have 10x more lightbulbs but now household appliance has an LED. I just installed new GFCI outlets and all of them have LEDs too!
  - sangnoir 2y ago
    The comparison becomes meaningless when we count the milliwatt, sub-Lumen LED in an outlet wirh incandescents. "I had 8 incandescent lightbulbs, but now have 1000s of LEDs- including outlets, TV backlights, DVR status" isn't comparing like with like.
    - ahmeneeroe-v2 2y ago
      Yeah probably a meaningless comparison for Jevons Paradox (and its application to NVDA) since that is about resource use and LEDs are not a resource
- mitthrowaway2 2y ago
  Jevons Paradox describes the situation where a 10x efficiency increase results in a >10x deployment of lumens, such that the amount of energy consumed for lightning increases relative to when lighting was inefficient.
  - aurareturn 2y ago
    Which has happened historically. Comparing this with the solid blue price line showing price indicates that the 100 fold fall in price per unit of light in the 20th century was due to increased efficiency, mainly as electricity replaced gas. Yet demand rose strongly over the period, increasing more than 100 fold. This challenges the view that increases in efficiency translate into reductions in demand, and thus emissions. https://onclimatechangepolicydotorg.wordpress.com/low-carbon-technologies-section-overview/long-term-trends-in-lighting-efficiency-and-consumption/ https://onclimatechangepolicydotorg.wordpress.com/low-carbon...

blagie 2y ago

Your math is wrong: > This felt false to me, LED bulbs are generally 10x more efficient, so the average number of lights would have had to increase 10 fold, and this is ignoring the savings from not having AC cool those other 50 watts a bulb that went to heat. The first 5W also went into heat. Perhaps with the exception of light escaping through a window, *every* watt that goes into a lightbulb comes out as heat for your AC to cool. I would not be surprised if there were a 10x increase in use of lighting with LEDs. Not taking Wikipedia (or any source) on blind trust is always wise. More often than not, when you kick tires, you come back to folklore. It's fine for big things, but details are often wrong. Ditto for newspapers, for that matter.

ApolloFortyNine 2y ago
If a 5w bulb and a 60w bulb output the same amount of light, those 55w are being wasted elsewhere (heat). I said 50 because I was afraid someone would go 'ACTUALLY LED's only save 50-55w', I didn't expect someone to argue that the 5w led bulb is also outputting heat. You are of course right, 2.5w of that 5w is likely heat being cooled by the AC. >I would not be surprised if there were a 10x increase in use of lighting with LEDs. Quite frankly I don't care either way, I just wanted a source. I'm happy you feel that way though.
- aurareturn 2y ago
  Quite frankly I don't care either way, I just wanted a source. I'm happy you feel that way though. This is the best write up I found for lighting source, efficiency, and consumption relationship. As a first step in looking at this, I’ve taken the data from the analysis and plotted it on a log scale. This shows clearly how consumption has increased as population and incomes (measured by per capita GDP) have risen and prices have fallen. The central role played by efficiency is indicated by the dashed line, which shows the number of kWh needed to produce a unit of light (1/efficiency). Comparing this with the solid blue price line showing price indicates that the 100 fold fall in price per unit of light in the 20th century was due to increased efficiency, mainly as electricity replaced gas. Yet demand rose strongly over the period, increasing more than 100 fold. This challenges the view that increases in efficiency translate into reductions in demand, and thus emissions. https://onclimatechangepolicydotorg.wordpress.com/low-carbon-technologies-section-overview/long-term-trends-in-lighting-efficiency-and-consumption/ https://onclimatechangepolicydotorg.wordpress.com/low-carbon...
HarHarVeryFunny 2y ago
> I would not be surprised if there were a 10x increase in use of lighting with LEDs. Has the average homeowner added more ceiling lights or lamps because of different bulbs? Has the average office added more lighting because of LEDs? Factories? In order for an overall 10x increase in usage, there needs to have been some MASSIVE new usage or expansion of lighting, somewhere, to make up for all of these enormous use cases (residential, commercial) where there was probably close to zero increase. So, do you have any pet theories ?!!
- blagie 2y ago
  > Has the average homeowner added more ceiling lights or lamps because of different bulbs? As much as I appreciate the snark and sarcasm, at least where I live, the equivalent is happening. Old home and commercial construction would typically have one central light per room. Homes would have a single light fixture with 1-3 lightbulbs at the center of each ceiling and were pretty dimly lit. Commercial would be similar with fluorescents. You would turn it off when you left a room. New home and commercial construction has accent lighting all over the place, some turned on 24/7. Cabinets have under-cabinet-lights. Closets have closet lights. We have rows of LEDs lining all sorts of accents. If you compare 80's-style construction to 2020's-style, the amount of new light seems to be about that much of an increase.
  - deleted 2y ago
    [deleted]
  - aurareturn 2y ago
    Not to mention that in poor countries, the invention of LEDs could mean going from being able to afford electricity for 1 light in the house to 10 lights.
  - HarHarVeryFunny 2y ago
    I can accept that new construction may have more lighting, but nowhere near 10x, and certainly not 10x overall when you factor "legacy locations" where it is mostly just a bulb replacement.

woadwarrior01 2y ago

This is exactly the case. Anecdotally speaking, growing up in the 90s, I remember my parents adding lightbulbs and fluorescent tube lights to their shopping list every couple of months. We used to have a small stockpile of these in the pantry. Fast forward to today, the last time I bought lightbulbs for my house was over 5 years ago and that was to upgrade from regular led lamps to Philips hue.

aurareturn 2y ago
Not the case I’m observing. My sister just did a home remodeling and she added must have been 50 LED recessed lights in the ceiling. There are automated LED lights in the outdoor pathways, lights hanging on the balcony rails, lights under kitchen cabinets, lights inside closets, lights inside pantries, solar powered LEDs in backyard, etc. Her appliances also have more indicator lights than ever before. I’m not even counting the countless LED screens such as phones, iPads, TVs. In total, she may every well have 10x more lights than before the LED boom. Time Square in NYC was famous for having many lights and screens. Walk around any large Asian city in 2025 and they all look like time square with countless lights and screens. Thats said, there is a limit to lighting demand because we still need darkness to sleep. I think the upper bound for intelligence is far higher than LED lights.
- Temporary_31337 2y ago
  Still it does not use as much electricity as the previous generation of light bulbs and she won’t be replacing them often. So from a perspective of the industry it’s not so good. The tech is better but there’s less sales / margins/ profits altogether.
  - aurareturn 2y ago
    Is this true? What were the revenues of lighting companies before compared to now? Do we count TV screen makers because they’re LEDs as well? I just watched Veritasium’s video on how LEDs were indented and the companies making LEDs saw exponential increase in revenue. https://youtu.be/AF8d72mA41M https://youtu.be/AF8d72mA41M Basic Google search tells me the lighting industry has experienced high growth due to the invention of LED lighting.

Ekaros 2y ago

I somewhat doubt there is now 10x light fixtures... Thus 10x the traditional bulbs. That seems rather large undertaking in most buildings. Sometimes I think it makes sense to stop and think what would 10x more of some items mean in practise.

quickthrowman 2y ago

LEDs are around 3-4x more efficient than fluorescent lamps, (1) 28W 2x4 LED fixture puts out around the same amount of light as (1) 4-lamp 2x4 fixture with (4) 28W fluorescent lamps, depending on the lumen output package on the LED fixture.

mitthrowaway2 2y ago
It's common to use incandescent bulbs as a baseline.

fragmede 2y ago

You're right. But it's wikipedia so I deleted the LED section and replaced it with a bit about cars.

aurareturn 2y ago

This felt false to me, LED bulbs are generally 10x more efficient, so the average number of lights would have had to increase 10 fold, and this is ignoring the savings from not having AC cool those other 50 watts a bulb that went to heat. Jevons Paradox does not state that there is a 1:1 relationship between efficiency increase and consumption. A 2x increase in efficiency does not always result in a 2x increase in consumption. With that said, it would not surprise me if there is a 10x increase in light sources (not total lumens) since LEDs.

ahmeneeroe-v2 2y ago
Yes, I don't have 10x more lightbulbs but now household appliance has an LED. I just installed new GFCI outlets and all of them have LEDs too!
- sangnoir 2y ago
  The comparison becomes meaningless when we count the milliwatt, sub-Lumen LED in an outlet wirh incandescents. "I had 8 incandescent lightbulbs, but now have 1000s of LEDs- including outlets, TV backlights, DVR status" isn't comparing like with like.
  - ahmeneeroe-v2 2y ago
    Yeah probably a meaningless comparison for Jevons Paradox (and its application to NVDA) since that is about resource use and LEDs are not a resource
mitthrowaway2 2y ago
Jevons Paradox describes the situation where a 10x efficiency increase results in a >10x deployment of lumens, such that the amount of energy consumed for lightning increases relative to when lighting was inefficient.
- aurareturn 2y ago
  Which has happened historically. Comparing this with the solid blue price line showing price indicates that the 100 fold fall in price per unit of light in the 20th century was due to increased efficiency, mainly as electricity replaced gas. Yet demand rose strongly over the period, increasing more than 100 fold. This challenges the view that increases in efficiency translate into reductions in demand, and thus emissions. https://onclimatechangepolicydotorg.wordpress.com/low-carbon-technologies-section-overview/long-term-trends-in-lighting-efficiency-and-consumption/ https://onclimatechangepolicydotorg.wordpress.com/low-carbon...