The books is good(ish) for it's time, but some of its analysis and forecasts are fundamentally flawed since it falls for the primary energy fallacy by comparing the chemical potential energy (in J) directly to electrical energy (also in J). The two are fundamentally different things and called be compared 1:1. E.g. To heat up your home with natural gas you need ~1J of chemical energy to get 1J of heat into the home, but with a electric heat pump you only need 1/6 J to get 1J of heat.
It is also a product of its time in terms of wind/solar vs nuclear. His forecasts of the impact of solar and wind is based on prices and performance from 2008. Prices have come down an order of magnitude since then, and performance and lifespan have increased drastically.
Heat pumps, and their efficiency (getting more than X Joules of heating for X Joules of electricity) are discussed in chapter 21 Smarter Heating, see for example the diagram and discussion on page 150: <a href="https://www.withouthotair.com/c21/page_150.shtml" rel="nofollow">https://www.withouthotair.com/c21/page_150.shtml
I imagine the economics (and perhaps technical improvements) of some things may have changed more than the book could forecast. But heat pumps were definitely understood by the author.
I’m not saying he was unaware of heat pumps, I’m saying he’s comparing apples to oranges simply because they use the same units.
Look at “3 - Cars” on page 29. He says the typical car uses 40 kWh/day. 40 kWh of what? Chemical energy in the gasoline.
The go to page 33 where he looks at how much energy onshore wind could produce per days in the UK. His number is 20 kWh/d. 20 kWh of what? electricity
He then compares those two numbers directly and uses that comparison as the basis of his arguments: “Britain’s onshore wind energy resource may be “huge,” but it’s evi-
dently not as huge as our huge consumption.”
This is simply incorrect. A combustion engine converts less than half of the chemical energy in the gasoline into mechanical work that can move the car. The electric model converts >90% of it. So we don’t have to replace 40 kWh/day, we have to replace less than half of that since the electric process is more efficient.
This same issues, the primary energy fallacy, underpins large parts of the book.
Thermal energy and electrical energy really are the same thing, not two different quantities that happen to be measured in the same units, like grams of lead and grams of gold, or your example of US dollars and Jamaican dollars. When you convert less than half of the chemical energy in the gasoline into mechanical work to move the car, the other 50+% of the energy is converted into heat. Carnot gives us a reversible conversion factor between them, but it depends on the combustion temperature rather than being some kind of constant, as in your Jamaican-dollar example.
Technically you can interconvert grams of lead and grams of gold one to one, too, but interconverting electrical and thermal energy is so easy that it happens all the time unintentionally.
MacKay does in fact cover the Carnot factor you're talking about; his Chapter 21 <a href="http://www.withouthotair.com/c21/page_140.shtml" rel="nofollow">http://www.withouthotair.com/c21/page_140.shtml begins:
> In the last chapter, we learned that electrification could shrink transport’s
energy consumption to one fifth of its current levels; and that public trans-
port and cycling can be about 40 times more energy-efficient than car-
driving. How about heating? What sort of energy-savings can technology
or lifestyle-change offer?
And then he goes into not just household heat pumps, and their achievable coefficients of performance, but also municipal combined heat and power, which take that ≈50% of the chemical energy "lost" from thermal power plants as waste heat and pumps it into your house.
So, far from being ignorant of the issue as you seem to be implying, he presents a more complete picture of the issues than you are presenting.
Specifically for household climate control, I suspect that both heat pumps and CHP are much less relevant now that we have cheap solar. You can think of a heat pump as a way to reduce the amount of solar-panel area that you need to heat your house. The trouble is that solar panels cost €0.13 per peak watt, while heat pumps cost closer to €1 per peak watt, so it may be cheaper to "waste" energy on heating your house resistively with a nichrome wire than to use a carefully engineered heat pump.
I'm pretty sure the barrier to the lead-gold mass parity is that due to nuclear stuff they're gonna not trade equal proton/neutron count and while of you flip the ratio you are merely dealing with an energy deficit/excess incurred as you're rearranging the protons and neutrons to transmute between gold and lead which by e=mc² is equivalent to mass... You're gonna run head first into the problem that we with our current proven understanding of atomic nucleus quantum physics, expect the energy excess to need to be turned into an equal split of matter *and antimatter*, which will foul your plans.
We're suspecting there to be some symmetry breakage to explain why we don't really see any globs of antimatter with our telescopes (at least none that show any evidence of being antimatter), but so far no (real) luck.
As for the "0.13€ vs. 1€": you're not gonna get much solar yield in peak winter at least in Central Europe, especially it's gonna be that your PV is going to charge <100hour electricity storage when the sun shows up on those winter days and the heat pump (at least the part that spends a little electricity to lift a lot of heat energy from outside temps to indoor temps) runs approximately continuously.
You might have some kind of e.g. water/water heat pump with salted (not table salt though) water deliberately thawing during daytime (by turning on the circulation between it and outside air) to freeze at much warmer than night air temperatures to buffer those "only mildly freezing" temperatures to improve the efficiency (and at that point, likely also the thermal output power) of the heat pump.
The radiators inside and potential fans for them would also go up in flow to make up for the increased losses through the walls/window-glass.
A big reason why at least in e.g. Germany heat pumps are not at all irrelevant vs. electric resistance "space heaters" is that they're also very efficient at handling spring/autumn (lower thermal delta to lift against; referencing to a resistance heater for scale/reference purposes but clearly not expecting that to be a benchmark) while easily offering summer cooling (with relatively minor incremental complexity).
I don't really know how inherently expensive it is to keep around at least for parts of each city, but existing natural gas central heating boilers are very useful to not just trash before they're broken just because one uogrades to a heat pump, specifically because they are already there (sunk cost/little scrap value) and have basically zero issue delivering extremely spiky power during unannounced winter days (well, takes maybe a day of notice to actually get crew in to the storage&distribution facilities, but weather forecasts easily cope).
Sure, it's not _efficient,_ but we could just divert some synthetic methane during summer to refill the caverns: we kinda want that (at least for hydrogen but methane works too at least for storage) anyways for chemical synthesis factories if we're not just gonna feed them crude oil/natural gas, so other than that chemical factories probably/largely prefer direct hydrogen, continuing to use our existing seasonal storage even if it's not getting refilled from NordStream2 but from local summer-only electrolysis plants and with more hydrogen than methane where the geology allows, seems to me just frugal dealings with nature (reduce, Reuse, recycle).
I think you can, in theory, break apart stable lead nuclei by spallation, transmuting some of them into somewhat lighter elements (first-row platinum-group elements, tungsten, that kind of thing), which you can fairly easily separate by chemical means, then bombard with neutrons and alpha particles until some of them become gold, go through another chemical separation step, and repeat. You need energy input for all of this, but I don't think you need to deal with significant quantities of antimatter, just the occasional positron emission.
I admit I don't know much about nuclear reactions, so please let me know if I'm talking nonsense here.
I agree that Central European capacity factors for solar are pretty bad, and that heat pumps are still economical in more polar countries, and will remain so for a few more years.
I'll answer the rest of your extremely interesting comment later, as I'm being drawn away at the moment, but I want you to know that I appreciate it very much.
_aavaa_ · · focus · HN ↗
It is also a product of its time in terms of wind/solar vs nuclear. His forecasts of the impact of solar and wind is based on prices and performance from 2008. Prices have come down an order of magnitude since then, and performance and lifespan have increased drastically.
azornathogron · · focus · HN ↗
I imagine the economics (and perhaps technical improvements) of some things may have changed more than the book could forecast. But heat pumps were definitely understood by the author.
_aavaa_ · · focus · HN ↗
Look at “3 - Cars” on page 29. He says the typical car uses 40 kWh/day. 40 kWh of what? Chemical energy in the gasoline.
The go to page 33 where he looks at how much energy onshore wind could produce per days in the UK. His number is 20 kWh/d. 20 kWh of what? electricity
He then compares those two numbers directly and uses that comparison as the basis of his arguments: “Britain’s onshore wind energy resource may be “huge,” but it’s evi- dently not as huge as our huge consumption.”
This is simply incorrect. A combustion engine converts less than half of the chemical energy in the gasoline into mechanical work that can move the car. The electric model converts >90% of it. So we don’t have to replace 40 kWh/day, we have to replace less than half of that since the electric process is more efficient.
This same issues, the primary energy fallacy, underpins large parts of the book.
kragen · · focus · HN ↗
Technically you can interconvert grams of lead and grams of gold one to one, too, but interconverting electrical and thermal energy is so easy that it happens all the time unintentionally.
MacKay does in fact cover the Carnot factor you're talking about; his Chapter 21 <a href="http://www.withouthotair.com/c21/page_140.shtml" rel="nofollow">http://www.withouthotair.com/c21/page_140.shtml begins:
> In the last chapter, we learned that electrification could shrink transport’s energy consumption to one fifth of its current levels; and that public trans- port and cycling can be about 40 times more energy-efficient than car- driving. How about heating? What sort of energy-savings can technology or lifestyle-change offer?
And then he goes into not just household heat pumps, and their achievable coefficients of performance, but also municipal combined heat and power, which take that ≈50% of the chemical energy "lost" from thermal power plants as waste heat and pumps it into your house.
So, far from being ignorant of the issue as you seem to be implying, he presents a more complete picture of the issues than you are presenting.
Specifically for household climate control, I suspect that both heat pumps and CHP are much less relevant now that we have cheap solar. You can think of a heat pump as a way to reduce the amount of solar-panel area that you need to heat your house. The trouble is that solar panels cost €0.13 per peak watt, while heat pumps cost closer to €1 per peak watt, so it may be cheaper to "waste" energy on heating your house resistively with a nichrome wire than to use a carefully engineered heat pump.
namibj · · focus · HN ↗
We're suspecting there to be some symmetry breakage to explain why we don't really see any globs of antimatter with our telescopes (at least none that show any evidence of being antimatter), but so far no (real) luck.
As for the "0.13€ vs. 1€": you're not gonna get much solar yield in peak winter at least in Central Europe, especially it's gonna be that your PV is going to charge <100hour electricity storage when the sun shows up on those winter days and the heat pump (at least the part that spends a little electricity to lift a lot of heat energy from outside temps to indoor temps) runs approximately continuously.
You might have some kind of e.g. water/water heat pump with salted (not table salt though) water deliberately thawing during daytime (by turning on the circulation between it and outside air) to freeze at much warmer than night air temperatures to buffer those "only mildly freezing" temperatures to improve the efficiency (and at that point, likely also the thermal output power) of the heat pump.
The radiators inside and potential fans for them would also go up in flow to make up for the increased losses through the walls/window-glass.
A big reason why at least in e.g. Germany heat pumps are not at all irrelevant vs. electric resistance "space heaters" is that they're also very efficient at handling spring/autumn (lower thermal delta to lift against; referencing to a resistance heater for scale/reference purposes but clearly not expecting that to be a benchmark) while easily offering summer cooling (with relatively minor incremental complexity).
I don't really know how inherently expensive it is to keep around at least for parts of each city, but existing natural gas central heating boilers are very useful to not just trash before they're broken just because one uogrades to a heat pump, specifically because they are already there (sunk cost/little scrap value) and have basically zero issue delivering extremely spiky power during unannounced winter days (well, takes maybe a day of notice to actually get crew in to the storage&distribution facilities, but weather forecasts easily cope).
Sure, it's not _efficient,_ but we could just divert some synthetic methane during summer to refill the caverns: we kinda want that (at least for hydrogen but methane works too at least for storage) anyways for chemical synthesis factories if we're not just gonna feed them crude oil/natural gas, so other than that chemical factories probably/largely prefer direct hydrogen, continuing to use our existing seasonal storage even if it's not getting refilled from NordStream2 but from local summer-only electrolysis plants and with more hydrogen than methane where the geology allows, seems to me just frugal dealings with nature (reduce, Reuse, recycle).
kragen · · focus · HN ↗
I admit I don't know much about nuclear reactions, so please let me know if I'm talking nonsense here.
I agree that Central European capacity factors for solar are pretty bad, and that heat pumps are still economical in more polar countries, and will remain so for a few more years.
I'll answer the rest of your extremely interesting comment later, as I'm being drawn away at the moment, but I want you to know that I appreciate it very much.