Indeed. I didn't read the whole thing but presumably that's Carnot efficiency of the nuclear reactor as heat engine? In which case .. who cares? The important factors are "is there going to be sufficient fuel?" (insert argument about breeder reactors), "is it cost (money or resource) effective", and "is the proliferation risk important".
By comparison, the increase in power/area efficiency of solar panels is useful but not very significant either; again, the critical factor is the cost falling by several orders of magnitude in the past decades.
I think you've pointed the one number that didn't make a substantive argument towards his thesis. The rest of the article is much more persuasive and uses facts that are more relevant.
Smil is the only degrowther that doesn't get totally dunked on by radical centrists types for being a degrowther, which I find interesting.
Apart from that oddity, it reinforces my thoughts that degrowthers are fairly rational people except they've fallen for the fossil fuel propaganda generated by people like Smil and then tried to take it seriously.
I'm not familiar with this blog but it appears the author falls into that group.
Smil to me shows that most people that talk about this subject are completely full of shit.
The subject is far too complicated to have any rational discussion on.
We use 55% more energy than in 1997? Where is all that going? I've seen graphs with plastic production with even higher numbers.
I have no problem going back to my 1997 lifestyle and cant point to much explaining this growth. Is it more people getting access to western luxury or are we just that much more wastefull?
> We use 55% more energy than in 1997? Where is all that going?
Mainly to rapidly developing countries like China and India. Europe and US have decreased fossil fuel consumption a bit, China and India have increased 3 fold.
> I have no problem going back to my 1997 lifestyle and cant point to much explaining this growth.
Approximately nobody in develping countries feels that way.
> Europe and US have decreased fossil fuel consumption a bit
We did not decreased fossil consumption we externalised the fossil consumption to developed countries production.
Developed countries use a lot of fossil fuels but most of that is to promote the lifestyle of developed countries.
Oxfam estimates that 1% of the richest people emit double the carbon emission of the half the poorest of humanity
I found the linked article to be difficult to follow. Vacliv Smil wrote a book called Energy and Civilization (2017) in which he argues that the ability to harness energy is what makes civilizations thrive and enables the production of culture.
Sure, full energy transition before 2050 isn't possible. But it should happen sooner or later, since fossil fuels aren't renewable. Doing this transition early allows to avoid shocks caused by fossil fuels exhaustion.
Also I am afraid that such transition isn't possible with current economic system and with current population. Resources needed for carbon-free economy are scarce (like copper mentioned in the article above), so, overall consumption reduction is necessary, maybe even with population reduction. This means degrowth, which isn't compatible with modern capitalism.
> isn't possible with current economic system and with current population
> This means degrowth, which isn't compatible with modern capitalism.
The reason people don't like discussing this stuff is that the logical conclusion is that the world will transition towards authoritarianism, in the form of fascism and/or something labelled "communism", while along the way a huge number of people will get killed.
Which is yet another reason to try to rush renewables.
Primary energy sources are what they are, both your comment and the linked article seem to imply discussing them should lead to a deserved punch in the face. Can you help me understand why?
As far as I can tell, your link argues that if we overcome all the practical challenges (politics, resources, financing, technical innovation) and go all-electric for global energy, we only need ~1/3 as much input energy potential as we use today for the same useful work. That’s useful, but the hard part lies in those practical challenges. And the primary sources of global human energy use are a long way away from that goal.
So should we strive to get there? Sure. Should we be tactical about how? Yes. And the link seems to argue that as well. But is it reasonable to hit our 2050 goals based on the current global fossil fuel usage? Not really. So I’m really missing how this refutes Smil’s article, and why “primary energy” is such a stupid thing.
The problem with it is that it makes it easy to make bad faith arguments for why we can’t or shouldn’t transition (kinda like is being done here).
Take for example paragraphs like:
> Primary electricity (hydro, nuclear, wind, solar, and a small contribution by geothermal plants) accounted for no more than about 18% of the world’s primary energy consumption, which means that fossil fuels still provided about 82% of the world’s primary energy supply in 2022.
Are used as justification for why green green energy is a scam, it can’t be done, or it’s too expensive, etc., etc. after all 82% of primary energy is still from fossil fuels.
Except we don’t have to replace 82%, since 2/3rds of that is wasted. Of 100 kWh we’re already done 12 kWh and only need to add 27 (NOT 82) more kWh of electricity to replace all the fossil fuel usage. And that’s before talking about any efficiency gains (e.g heat pumps with COP >4).
Ah, seems like I was missing some context where the fossil fuel and anti-renewable folks have been using the term in arguments against trying to change.
I’m not sure of Smil’s politics but to be fair, there’s nothing in that quote that is inherently misleading. I can see through how others could spin it, and I’ll be more careful knowing the term has some politics behind it now. To me his argument in the article is that it’s not practical to expect a transition in a 25-year timescale, not that it’s impossible or not worth working on.
Heat pumps are a good example where the practice has been a lot harder than we might hope. Sure COP > 4 for heating is great, but the units are very expensive today, and in most of the US and Europe with sub-zero winter temps operate with much worse efficiencies, making them significantly more expensive to operate. I’m sure with effort those issues will improve, and major policy shifts can help mitigate some of the costs. But especially without a strong will today those changes are practically too far off for the 2050 target.
> there’s nothing in that quote that is inherently misleading
The discussion of the issue in terms of primary energy is the very thing that's inherently misleading. To move away from fossil fuels we do not have to replace the primary energy, we have to replace the useful energy that comes out the other side. From the Sankey diagram in the article I linked [0], 67.5 units of energy are not useful energy.
To put it to an extreme, instead of 67.5 units beings wastes, it could be 100 billion units for 32.5 units of useful energy produces. Focusing on the 100 billion is inherently misleading since they are irrelevant when the replacement technology basically creates the useful energy with over 100% efficiency at times.
Heat pumps. Yes their COP is lower during cold winters, but that brings in 2 discussions.
1) any COP value above 1 means that we'll need less primary energy than when buying something, and even in cold weather they manage a COP above that [1].
2) Lower COPs will cost you more, depending on what your natural gas prices are like due to any crazed lunatics invading their neighbours. Which conincidentally is only what pushes electricity prices up in many places that use natural gas for electricity (even just peak demand).
The capital cost difference also depends drastically on situation. Many climates need both heating and cooling, so the price of heat pump versus furnace + AC unit is much smaller than heat pump versus furnace.
> But especially without a strong will today those changes are practically too far off for the 2050 target.
I agree, and even replacing the 1/3rd of the primary energy will be a tough challenge. But Vaclav continual framing in terms of primary energy is actively used to push inaction. His critics have been vocal about this point (and others) for a while, he should know better by now.
Thanks, you have helped at least me think a bit differently about this. I still believe primary energy is a valid way to look at the problem, but see more clearly how easily it can lead an uninformed audience to a bad conclusion.
And on heat pumps - it’s sad to reflect that even if we replaced all heating, it’s still only a couple % of the total rejected heat. There are few easy wins in this game, just many different ways we need to chip away at it.
> it’s sad to reflect that even if we replaced all heating, it’s still only a couple % of the total rejected heat.
It's actually not as bad as it looks.
Even if the home heating is not the biggest contributor from that chart, it is still a worthwhile target. Though EVs are likely a more impactful choice.
One thing not captured by that chart are the 2nd order effects of either heat pump or EV switching. Part of what makes switching economically unattractive (aside from allowing the fossil fuel options to pollute for free) are the economies of scale present for fossil fuels. However, those same economies of scale can easily flip to diseconmics of scale as customers switch away. Every ICE car replaced by an EV makes gasoline and diesel more expensive, the same thing for heat pumps and natural gas andheating oil.
So for natural gas, removing the stream going to residential, significantly impacts the economic calculation for commercial and industrial uses.
For gasoline and diesel, the impact as even more serious. Out of every barrel of crude oil 70% gets turned into gasoline/diesel [0]. The unit economics there are going to be even worse as gasoline demand continues to drop.
A gas furnace converts 1 J of chemical potential energy (higher heating value for natural gas) into essentially 1 J of internal energy in the air (raising it’s temperature).
A heat pump can take 1 J of electricity and move (realistically) up to 5 J of internal energy from A to B.
A layman description (if not actually accurate) is that while a gas furnace (or electric resistive heating) can be 100% efficient, a heat pump can be 500% efficient.
Can you point me to the actual literature on the mechanics of heat pumps b/c I don't think you're explaining properly what's going on. If you can get 5J out of 1J then you have a perpetual motion machine & those are physically & logically impossible (assuming physically relevant axioms).
Links below, tldrs here: A heat pump does what the name suggests: it pumps heat. Resistive heating and burning gas is converting energy from one form into another. A heat pumps moves energy from A to B (making A colder and B hotter in the process) in literally the same way AC units
You get 5 J of heat out for every 1 J of electricity in because we're being funny with the units. You put in 1 J of electricity and the rest is put in as heat from your source (A) and then moved into B.
That obviously doesn't make sense if you know basic physics. Converting gas into heat by combusting it heats up the air in the room directly. Burning that gas in a turbine & then transferring that energy through a bunch of transformers to get to the heat pump can't give you more heat than what went into combusting the gas in the first place. This obviously doesn't work in reverse to cool a room but the direction I laid out is obviously correct.
You're not using funny units, you're confused about the thermodynamics of the situation. Heat pumps are more efficient air coolers than standard air conditioners but they're not giving you more energy than what you put into it.
> you're confused about the thermodynamics of the situation.
I assure you I am not, it is actually you who still seem confused about where the energy is coming from.
> they're not giving you more energy than what you put into it.
When you burn gas in a furnace, all of the energy that raises the temperature of the house comes from the gas.
When you run a heat pump you have two sources of energy:
1. Electricity running the thing.
2. Heat from the outside that you're moving inside.
#2 is where most of the energy that actually heats up the house comes from. The electricity is used to move it from outside the house to inside.
> Burning that gas in a turbine & then transferring that energy through a bunch of transformers to get to the heat pump can't give you more heat than what went into combusting the gas in the first place.
It actually can. A combined cycle plant can be ~60% efficient (chemical energy -> electricity). Say another 70% for getting it from the plant to your heat pump, then a COP 3 (or "efficiency" of 300%) gives you 0.6x0.7x3 or 1.26. So for every J of natural gas you burn in that plant, you'll heat your house with 1.26 J (compared to at best 1 J, realistically 0.9 J, for a gas furnace).
If you instead look at a ground source heat pump, you can get a COP of ~7 [0]. You're now putting ~3 J of heat into your house of each J of natural gas.
That's clever accounting but your overall system (house + outside + plant + fuel) is still less than 100% efficient. That's basic physics/thermodynamics.
Heat pumps are basically taking advantage of solar + geothermal radiation that ends up in the ground & air but once you account for the solar + geo radiation then it becomes obvious that all a heat pump is doing is accelerating the production of entropy. You're either normalizing the delta between inside & outside or increasing it but in both cases the overall entropy of the system goes up. Whereas your accounting seems to suggest you somehow get more energy than what was available which is obviously unphysical.
But my accounting was always about the energy that we as humans need to supply. This discussion was originally about how talking about the energy transition in terms of primary energy is inherently misleading.
A heat pump does not magically create the difference between work input and heat output, it pulls it from second source. But that source is free. All we have to provide is the work.
Replacing a gas burner with a heat pump does not require us to replace 1 J of chemical potential energy with 1 J of electricity, instead replace it with 0.33 J of electricity (or even less).
> Nuclear electricity generation has been only 33% efficient (and no imminent breakthroughs are expected).
This is a good example of the pointless numerology deployed against renewables by people like Smil, because he's doing it to nuclear here.
What does this number mean in real life? Basically nothing. Why is he bringing it up then?. Because it sounds like a low number.
Most of the numbers he uses are used because they sound like a big number. That's the level of debate he's aiming for.
Indeed. I didn't read the whole thing but presumably that's Carnot efficiency of the nuclear reactor as heat engine? In which case .. who cares? The important factors are "is there going to be sufficient fuel?" (insert argument about breeder reactors), "is it cost (money or resource) effective", and "is the proliferation risk important".
By comparison, the increase in power/area efficiency of solar panels is useful but not very significant either; again, the critical factor is the cost falling by several orders of magnitude in the past decades.
I think you've pointed the one number that didn't make a substantive argument towards his thesis. The rest of the article is much more persuasive and uses facts that are more relevant.
Smil is the only degrowther that doesn't get totally dunked on by radical centrists types for being a degrowther, which I find interesting.
Apart from that oddity, it reinforces my thoughts that degrowthers are fairly rational people except they've fallen for the fossil fuel propaganda generated by people like Smil and then tried to take it seriously.
I'm not familiar with this blog but it appears the author falls into that group.
Smil to me shows that most people that talk about this subject are completely full of shit. The subject is far too complicated to have any rational discussion on.
Definitely worth checking out his book, how the world really works if you're not that into or across this stuff, really fascinating.
https://vaclavsmil.com/book/how-the-world-really-works-2/
We use 55% more energy than in 1997? Where is all that going? I've seen graphs with plastic production with even higher numbers.
I have no problem going back to my 1997 lifestyle and cant point to much explaining this growth. Is it more people getting access to western luxury or are we just that much more wastefull?
> We use 55% more energy than in 1997? Where is all that going?
Mainly to rapidly developing countries like China and India. Europe and US have decreased fossil fuel consumption a bit, China and India have increased 3 fold.
> I have no problem going back to my 1997 lifestyle and cant point to much explaining this growth.
Approximately nobody in develping countries feels that way.
> Europe and US have decreased fossil fuel consumption a bit We did not decreased fossil consumption we externalised the fossil consumption to developed countries production.
Developed countries use a lot of fossil fuels but most of that is to promote the lifestyle of developed countries.
Oxfam estimates that 1% of the richest people emit double the carbon emission of the half the poorest of humanity
https://www.oxfam.org/en/press-releases/carbon-emissions-ric...
I found the linked article to be difficult to follow. Vacliv Smil wrote a book called Energy and Civilization (2017) in which he argues that the ability to harness energy is what makes civilizations thrive and enables the production of culture.
Sure, full energy transition before 2050 isn't possible. But it should happen sooner or later, since fossil fuels aren't renewable. Doing this transition early allows to avoid shocks caused by fossil fuels exhaustion.
Also I am afraid that such transition isn't possible with current economic system and with current population. Resources needed for carbon-free economy are scarce (like copper mentioned in the article above), so, overall consumption reduction is necessary, maybe even with population reduction. This means degrowth, which isn't compatible with modern capitalism.
> isn't possible with current economic system and with current population
> This means degrowth, which isn't compatible with modern capitalism.
The reason people don't like discussing this stuff is that the logical conclusion is that the world will transition towards authoritarianism, in the form of fascism and/or something labelled "communism", while along the way a huge number of people will get killed.
Which is yet another reason to try to rush renewables.
Here we go gesticulating at “primary energy” again.
https://spitfireresearch.com/the-primary-energy-fallacy/
Primary energy sources are what they are, both your comment and the linked article seem to imply discussing them should lead to a deserved punch in the face. Can you help me understand why?
As far as I can tell, your link argues that if we overcome all the practical challenges (politics, resources, financing, technical innovation) and go all-electric for global energy, we only need ~1/3 as much input energy potential as we use today for the same useful work. That’s useful, but the hard part lies in those practical challenges. And the primary sources of global human energy use are a long way away from that goal.
So should we strive to get there? Sure. Should we be tactical about how? Yes. And the link seems to argue that as well. But is it reasonable to hit our 2050 goals based on the current global fossil fuel usage? Not really. So I’m really missing how this refutes Smil’s article, and why “primary energy” is such a stupid thing.
The problem with it is that it makes it easy to make bad faith arguments for why we can’t or shouldn’t transition (kinda like is being done here).
Take for example paragraphs like:
> Primary electricity (hydro, nuclear, wind, solar, and a small contribution by geothermal plants) accounted for no more than about 18% of the world’s primary energy consumption, which means that fossil fuels still provided about 82% of the world’s primary energy supply in 2022.
Are used as justification for why green green energy is a scam, it can’t be done, or it’s too expensive, etc., etc. after all 82% of primary energy is still from fossil fuels.
Except we don’t have to replace 82%, since 2/3rds of that is wasted. Of 100 kWh we’re already done 12 kWh and only need to add 27 (NOT 82) more kWh of electricity to replace all the fossil fuel usage. And that’s before talking about any efficiency gains (e.g heat pumps with COP >4).
Ah, seems like I was missing some context where the fossil fuel and anti-renewable folks have been using the term in arguments against trying to change.
I’m not sure of Smil’s politics but to be fair, there’s nothing in that quote that is inherently misleading. I can see through how others could spin it, and I’ll be more careful knowing the term has some politics behind it now. To me his argument in the article is that it’s not practical to expect a transition in a 25-year timescale, not that it’s impossible or not worth working on.
Heat pumps are a good example where the practice has been a lot harder than we might hope. Sure COP > 4 for heating is great, but the units are very expensive today, and in most of the US and Europe with sub-zero winter temps operate with much worse efficiencies, making them significantly more expensive to operate. I’m sure with effort those issues will improve, and major policy shifts can help mitigate some of the costs. But especially without a strong will today those changes are practically too far off for the 2050 target.
> there’s nothing in that quote that is inherently misleading
The discussion of the issue in terms of primary energy is the very thing that's inherently misleading. To move away from fossil fuels we do not have to replace the primary energy, we have to replace the useful energy that comes out the other side. From the Sankey diagram in the article I linked [0], 67.5 units of energy are not useful energy.
To put it to an extreme, instead of 67.5 units beings wastes, it could be 100 billion units for 32.5 units of useful energy produces. Focusing on the 100 billion is inherently misleading since they are irrelevant when the replacement technology basically creates the useful energy with over 100% efficiency at times.
Heat pumps. Yes their COP is lower during cold winters, but that brings in 2 discussions.
1) any COP value above 1 means that we'll need less primary energy than when buying something, and even in cold weather they manage a COP above that [1].
2) Lower COPs will cost you more, depending on what your natural gas prices are like due to any crazed lunatics invading their neighbours. Which conincidentally is only what pushes electricity prices up in many places that use natural gas for electricity (even just peak demand).
The capital cost difference also depends drastically on situation. Many climates need both heating and cooling, so the price of heat pump versus furnace + AC unit is much smaller than heat pump versus furnace.
> But especially without a strong will today those changes are practically too far off for the 2050 target.
I agree, and even replacing the 1/3rd of the primary energy will be a tough challenge. But Vaclav continual framing in terms of primary energy is actively used to push inaction. His critics have been vocal about this point (and others) for a while, he should know better by now.
[0]: https://spitfireresearch.com/wp-content/uploads/2024/06/LLNL...
[1]: https://www.sciencedirect.com/science/article/pii/S254243512...
Thanks, you have helped at least me think a bit differently about this. I still believe primary energy is a valid way to look at the problem, but see more clearly how easily it can lead an uninformed audience to a bad conclusion.
And on heat pumps - it’s sad to reflect that even if we replaced all heating, it’s still only a couple % of the total rejected heat. There are few easy wins in this game, just many different ways we need to chip away at it.
I'm glad it was helpful.
> it’s sad to reflect that even if we replaced all heating, it’s still only a couple % of the total rejected heat.
It's actually not as bad as it looks.
Even if the home heating is not the biggest contributor from that chart, it is still a worthwhile target. Though EVs are likely a more impactful choice.
One thing not captured by that chart are the 2nd order effects of either heat pump or EV switching. Part of what makes switching economically unattractive (aside from allowing the fossil fuel options to pollute for free) are the economies of scale present for fossil fuels. However, those same economies of scale can easily flip to diseconmics of scale as customers switch away. Every ICE car replaced by an EV makes gasoline and diesel more expensive, the same thing for heat pumps and natural gas andheating oil.
So for natural gas, removing the stream going to residential, significantly impacts the economic calculation for commercial and industrial uses.
For gasoline and diesel, the impact as even more serious. Out of every barrel of crude oil 70% gets turned into gasoline/diesel [0]. The unit economics there are going to be even worse as gasoline demand continues to drop.
[0]: https://www.eia.gov/tools/faqs/faq.php?id=327&t=9
> the replacement technology basically creates the useful energy with over 100% efficiency
I think you're confused. There is no way to avoid the laws of thermodynamics so where are you getting more than 100% efficiency?
Efficiency is not the correct word here.
A gas furnace converts 1 J of chemical potential energy (higher heating value for natural gas) into essentially 1 J of internal energy in the air (raising it’s temperature).
A heat pump can take 1 J of electricity and move (realistically) up to 5 J of internal energy from A to B.
A layman description (if not actually accurate) is that while a gas furnace (or electric resistive heating) can be 100% efficient, a heat pump can be 500% efficient.
Can you point me to the actual literature on the mechanics of heat pumps b/c I don't think you're explaining properly what's going on. If you can get 5J out of 1J then you have a perpetual motion machine & those are physically & logically impossible (assuming physically relevant axioms).
It's likely I am not.
Links below, tldrs here: A heat pump does what the name suggests: it pumps heat. Resistive heating and burning gas is converting energy from one form into another. A heat pumps moves energy from A to B (making A colder and B hotter in the process) in literally the same way AC units
You get 5 J of heat out for every 1 J of electricity in because we're being funny with the units. You put in 1 J of electricity and the rest is put in as heat from your source (A) and then moved into B.
A good YouTube video: https://www.youtube.com/watch?v=7J52mDjZzto
That obviously doesn't make sense if you know basic physics. Converting gas into heat by combusting it heats up the air in the room directly. Burning that gas in a turbine & then transferring that energy through a bunch of transformers to get to the heat pump can't give you more heat than what went into combusting the gas in the first place. This obviously doesn't work in reverse to cool a room but the direction I laid out is obviously correct. You're not using funny units, you're confused about the thermodynamics of the situation. Heat pumps are more efficient air coolers than standard air conditioners but they're not giving you more energy than what you put into it.
> you're confused about the thermodynamics of the situation.
I assure you I am not, it is actually you who still seem confused about where the energy is coming from.
> they're not giving you more energy than what you put into it.
When you burn gas in a furnace, all of the energy that raises the temperature of the house comes from the gas.
When you run a heat pump you have two sources of energy:
1. Electricity running the thing.
2. Heat from the outside that you're moving inside.
#2 is where most of the energy that actually heats up the house comes from. The electricity is used to move it from outside the house to inside.
> Burning that gas in a turbine & then transferring that energy through a bunch of transformers to get to the heat pump can't give you more heat than what went into combusting the gas in the first place.
It actually can. A combined cycle plant can be ~60% efficient (chemical energy -> electricity). Say another 70% for getting it from the plant to your heat pump, then a COP 3 (or "efficiency" of 300%) gives you 0.6x0.7x3 or 1.26. So for every J of natural gas you burn in that plant, you'll heat your house with 1.26 J (compared to at best 1 J, realistically 0.9 J, for a gas furnace).
If you instead look at a ground source heat pump, you can get a COP of ~7 [0]. You're now putting ~3 J of heat into your house of each J of natural gas.
[0]: https://en.wikipedia.org/wiki/Heat_pump#Performance
That's clever accounting but your overall system (house + outside + plant + fuel) is still less than 100% efficient. That's basic physics/thermodynamics.
Heat pumps are basically taking advantage of solar + geothermal radiation that ends up in the ground & air but once you account for the solar + geo radiation then it becomes obvious that all a heat pump is doing is accelerating the production of entropy. You're either normalizing the delta between inside & outside or increasing it but in both cases the overall entropy of the system goes up. Whereas your accounting seems to suggest you somehow get more energy than what was available which is obviously unphysical.
Sure.
But my accounting was always about the energy that we as humans need to supply. This discussion was originally about how talking about the energy transition in terms of primary energy is inherently misleading.
A heat pump does not magically create the difference between work input and heat output, it pulls it from second source. But that source is free. All we have to provide is the work.
Replacing a gas burner with a heat pump does not require us to replace 1 J of chemical potential energy with 1 J of electricity, instead replace it with 0.33 J of electricity (or even less).
there is energy transition