> To light the factories, more energy used to correlate with more light, until we swap out the incandescent/halogen lighting sources for LEDs
this is nonsense. lighting hasn't been a significant fraction of the energy usage of factories since they switched from being lighted by fireplaces to gaslighting. not in 02024, not in 01974, not in 01924, not in 01874
> Seems that measuring [gdp] growth by energy consumption is like Bill Gates' famous example
it's true that higher efficiency is better, of course, but your comment embeds the false assumption that higher energy efficiency reduces energy use. in fact, higher energy efficiency usually increases energy use, because it increases the scope of things to which marketed energy can be economically applied more than it reduces the use of marketed energy for things it was already being used for. (this is the well-known jevons paradox mentioned in https://news.ycombinator.com/item?id=41392248). so, even today, it turns out that the countries with the lowest gdp and lowest energy use also have the lowest energy efficiency
similarly, using high-level languages reduces the number of lines of code to implement some given functionality; but you would be completely mistaken if you used that fact to predict that the vast majority of programmers spend their time writing assembly language instead of python because python requires one twentieth of the code to do whatever. many things are done with python not just because companies writing python outcompete companies writing assembly, but also because programs that would be unprofitable to write in assembly language become profitable to write when you can write them in high-level languages!
>> lighting hasn't been a significant fraction of the energy usage of factories
Right, but it is an easy example to explain at the outset and why in the literal next sentence I mentioned: "Same for more efficient motors, swapping ovens for inductive heating, more efficient processes, etc."
>> embeds the false assumption that higher energy efficiency reduces energy use
NO. I am describing a COMPLETELY different effect. I am not talking about marketing anything, but the results of improved process efficiencies.
If Company X, or an entire industry, switch from large inefficient ovens to spot-heating, and still produce the same number of widgets for 10% of the energy, the energy used has entirely decoupled from economic output. Same GDP, lower energy consumption. Or, if the new widgets are cheaper and more get sold, then greater GDP and smaller energy consumption number.
The point is, regardless of all the knock-on and sometimes paradoxical effects, the previously strong 1:1 correlation of energy use to GDP starts to break when efficiency-enabling technologies gain widespread adoption.
There are also paradoxical questions such as what happens when Company X switches entirely from oil heat and electricity to on-site solar & batteries, producing the same number of widgets using the same total energy? The GDP seems to go down because oil is no longer being pumped, transported, refined, and transported again to Company X's factories, but the output is the same, so the same net goods flow into the economy. The entire enterprise of getting refined oil to Company X is now shown to be redundant to production. But also, the energy usage as measured at the grid went to zero.
Again, the point is, the not only is the relationship of energy-GDP unstable, the entire measurement of GDP is problematic.
this is nonsense. lighting hasn't been a significant fraction of the energy usage of factories since they switched from being lighted by fireplaces to gaslighting. not in 02024, not in 01974, not in 01924, not in 01874
> Seems that measuring [gdp] growth by energy consumption is like Bill Gates' famous example
it's true that higher efficiency is better, of course, but your comment embeds the false assumption that higher energy efficiency reduces energy use. in fact, higher energy efficiency usually increases energy use, because it increases the scope of things to which marketed energy can be economically applied more than it reduces the use of marketed energy for things it was already being used for. (this is the well-known jevons paradox mentioned in https://news.ycombinator.com/item?id=41392248). so, even today, it turns out that the countries with the lowest gdp and lowest energy use also have the lowest energy efficiency
similarly, using high-level languages reduces the number of lines of code to implement some given functionality; but you would be completely mistaken if you used that fact to predict that the vast majority of programmers spend their time writing assembly language instead of python because python requires one twentieth of the code to do whatever. many things are done with python not just because companies writing python outcompete companies writing assembly, but also because programs that would be unprofitable to write in assembly language become profitable to write when you can write them in high-level languages!