5 ms·

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, an

by 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.

by blagie 2y ago

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.