8 ms·

We'd still need tens of thousands of these plants. From [0] it's mentioned that > According to Andreas Sizmann, SOLAR-JET project coordinator at BHL, a solar r

by jfim 4y ago

We'd still need tens of thousands of these plants. From [0] it's mentioned that > According to Andreas Sizmann, SOLAR-JET project coordinator at BHL, a solar reactor with a 1 km2 solar field could generate 20,000 L/d of kerosene, which could fly a large 300-body commercial airliner for about seven hours. According to [1] there are about 10000 planes in the air at any moment (excluding private jets, military, and cargo planes): > Back in 2017, FlightAware determined there to be an average of 9,728 commercial airplanes in the sky at any given time. Of course, that number fluctuates on a minute-by-minute basis, given that planes are nearly constantly taking off and landing. Doing the math of 10000 × (24 ÷ 7) gives us 35285 of these one square kilometer plants, or about 12% of the area of the entire state of Nevada. So it might be actually doable from a back of the envelope math analysis, but it'd be quite a big endeavor to scale a facility that large. [0] https://www.thechemicalengineer.com/news/first-kerosene-made-from-solar-syngas/ https://www.thechemicalengineer.com/news/first-kerosene-made... [1] https://www.travelandleisure.com/airlines-airports/number-of-planes-in-air https://www.travelandleisure.com/airlines-airports/number-of...

dredmorbius 4y ago
The vast bulk of air travel is either intranational (domestic flights) or intracontinental (as with Europe, Asia, and Africa). For both, a well-developed high-speed rail network competes exceptionally well. Short-haul flights are comparatively less efficient than long-haul as the high-energy take-off portion represents a greater fraction of total flight time. Once airborne, aircraft are remarkably efficient --- rougly on par with (single-occupant) automobile travel on a per-kilometer basis. (On a unit-time basis, of course, consumption is roughly 10x greater, and the induced travel via the Jevons paradox from reduced costs is considerable.) But developing high-speed rail networks within countries and contiguous continental regions substitutes for a huge fraction of air travel. It might also offload a considerable amount of overnight / express cargo delivery which presently moves by plane. Cargo utilisation of HSR might balance out passenger travel patterns and allow flexible capacity response to boot.
- xhkkffbf 4y ago
  But rail has issues of its own. The biggest may be the amount of land it takes up. While the rail lines are thin, they are very long. And if you want them to be high speed, you can't have cars crossing them. So they're very expensive to build and they require taking plenty of land out of circulation.
  - dredmorbius 4y ago
    Curious fact I discovered a few years ago: land use by airports and railroads in the US is roughly the same. Airports tend to be large sprawling regions of urban land. Rail tends to be linear. I'm not sure that the comparison is entirely fair: rail accounts for a small fraction of total passenger travel (though commuter rail is a surprisingly large portion). However there's an astounding amount of freight rail. It's also possible to dual-use land near rail, especially where it counts (urbanised regions), through elevated, trenched, or subway routing. Mind, even then there may be noise and vibration issues, so you'd probably want to keep rail at some distance from residential areas, though I hear airports may have similar issues as well. Freight rail also has a history of very large switching yards in areas. Compare the CSX yards near Chicago Midway Airport. Net direct land use appears roughly comparable. https://www.openstreetmap.org/search?query=41.7813916%2C%2D87.770125#map=14/41.7814/-87.7701 https://www.openstreetmap.org/search?query=41.7813916%2C%2D8... Mind that other transport modes also have large land-use demands. Private automobiles command a third or more of all land in many cities through streets and parking.
    - xhkkffbf 4y ago
      Sure, Midway and the freight yards use about the same amount of space. The point is that the rail uses a thin strip between towns. And if a road is to cross it, you've got to build an underpass or an overpass. The topological challenges are big. Of course you're right about dual use and adjacencies and everything. It's the land between the towns that really is the issue. The airplanes are up at 30,000 feet.
      - 4y ago
41b696ef1113 4y ago
How many oil wells/barrels/square kilometers are currently dedicated to producing the world's jet fuel needs?
- zachrose 4y ago
  About the same amount of land. In North America alone, 30,000 square kilometers for all oil and gas[0]. For a rough approximation, the US produced 14% of oil in the world in 2021[1] and this guy on Quora[2] says that 12% of the world's oil and gas goes into aviation fuel. [0] https://www.science.org/content/article/thirty-thousand-square-kilometers-land-lost-oil-and-gas-development https://www.science.org/content/article/thirty-thousand-squa... [1] https://en.wikipedia.org/wiki/List_of_countries_by_oil_production https://en.wikipedia.org/wiki/List_of_countries_by_oil_produ... [2] https://www.quora.com/What-percentage-of-the-world-s-crude-oil-is-used-for-gasoline-diesel-and-jet-fuel https://www.quora.com/What-percentage-of-the-world-s-crude-o...
  - leaflets2 4y ago
    Already pipelines running from those areas :-) maybe in the future can transport solar jet fuel instead?
  - Armisael16 4y ago
    That’s all oil and gas activity; jet fuel accounts for only a very small fraction of that.
- dsmmcken 4y ago
  Wow, the US has just under a million operating U.S. oil and natural gas wells? That number surprised me, I don't know what I expected but I wouldn't have guessed that many. https://www.eia.gov/petroleum/wells/pdf/full_report.pdf https://www.eia.gov/petroleum/wells/pdf/full_report.pdf
  - mrep 4y ago
    Well, we are the largest producer of oil in the world: https://en.wikipedia.org/wiki/List_of_countries_by_oil_production https://en.wikipedia.org/wiki/List_of_countries_by_oil_produ...
jonnycomputer 4y ago
According to [1], 8,400,000 acres have been disturbed by surface coal mining in the United States. My calculations makes that almost 34,000 square kilometers disturbed by surface coal mining. [1] https://www.gem.wiki/The_footprint_of_coal https://www.gem.wiki/The_footprint_of_coal
- deleted 4y ago
  [deleted]
- bpodgursky 4y ago
  While I am the last person to minimize how bad coal is compared to every other option, "disturbed" does not mean "blackened death, devoid of life" in most cases. There are a lot of replanted strip-mined mountains. It's not good, but does revert to nature... mostly.
  - jonnycomputer 4y ago
    Point taken.
  - ace2358 4y ago
    Yikes, that’s quite a bit of mental gymnastics you’re pulling there. Coal mines are horrible when they’re open and the horrible once they’re closed, don’t believe the P.R.
    - bpodgursky 4y ago
      Yes coal mines are horrible. However, reclaimed mines are not worse for the environment than literally replacing equivalent acreage with a blanket of monolithic fused-silicon solar collectors (under which, there is no environment). My point is not that coal is good, it is that the acreage comparison is not good.
      - jonnycomputer 4y ago
        What about putting solar on those old coal mines?
ETH_start 4y ago
What kind of raw materials are needed to cover 35,285 square kilometers with solar panels?
- wumpus 4y ago
  "Solar panels" usually means solar cells. These are mirrors.
richardw 4y ago
Sooner or later we have to price carbon externalities correctly, and fund development of offsets. It’ll be later of course, but it’s the rational course. Restating your math slightly, how can 3.5 of these be funded by a carbon fee from ~365 flights a year over 20 years? Doesn’t seem like an impossible problem to think through and at least gives us a path to a renewable cycle.
- hgomersall 4y ago
  My view is you should pay the cost of removing the carbon you emit. The market forces would then give a very strong incentive to both be much less carbon intensive as well as develop better co2 removal strategies.
- ThomPete 4y ago
  As always you need to factor in both positive and negative externalities. If you do that, the positive would still come out way way ahead. (And not it's not priced in already contrary to popular belief) The reality is that we can't sustain a civilisation of 8billion people without fossil fuels. We should do what we can to find alternatives that are less pollutant and have higher energy density but for now that means fusion, thorium and traditional fission. But we still have to solve the materials issue and we still have to content with the fact that only 20% of our energy is based on electricity and any attempt at increasing that number will require lots of fossil fuel usage as you would have to replace all the machines out there. We are going to be dependent on FF for a long long time.
  - kaibee 4y ago
    > The reality is that we can't sustain a civilisation of 8billion people without fossil fuels. We should do what we can to find alternatives that are less pollutant and have higher energy density but for now that means fusion, thorium and traditional fission. This is just a failure to understand how much sunlight there is and how fast solar panels are getting cheaper.
    - ThomPete 4y ago
thatjoeoverthr 4y ago
It only really matters if any particular facility is profitable. If so, they’re will exist and supply some portion of the fuel. There isn’t any reason to think they need to supply all of it.
nicoburns 4y ago
> Back in 2017, FlightAware determined there to be an average of 9,728 commercial airplanes in the sky at any given time. Of course, that number fluctuates on a minute-by-minute basis, given that planes are nearly constantly taking off and landing. It seems unlikely that we'll be able to sustain the same level of air travel once we're no longer able to rely on cheap fossil fuels for it. I suspect air travel will get a lot more expensive and less common.
- shuger 4y ago
  > once we're no longer able to rely on cheap fossil fuels for it Why would that happen?
  - MattPalmer1086 4y ago
    Because it becomes uneconomical to extract and process? And of course, eventually it will run out if we don't stop using it first.
    - igravious 4y ago
      That's the question: why would it become uneconomical to extract and process? https://www.worldometers.info/oil/ https://www.worldometers.info/oil/ 47 years of oil left given current reserve estimates, I'd bet my life there's a couple of centuries left at least Interesting top 11: 1 Venezuela 299,953,000,000 18.2% sanctions/attempted coup 2 Saudi Arabia 266,578,000,000 16.2% strategic ally (petrodollar) 3 Canada 170,863,000,000 10.4% neighbour 4 Iran 157,530,000,000 9.5% sanctions/coup 5 Iraq 143,069,000,000 8.7% invaded 6 Kuwait 101,500,000,000 6.1% friendly relations 7 U.A.E 97,800,000,000 5.9% friendly relations 8 Russia 80,000,000,000 4.8% sanctions/global rival 9 Libya 48,363,000,000 2.9% bombed/destabilized 10 Nigeria 37,070,000,000 2.2% friendly? 11 United States 35,230,000,000 2.1% *ahem*
      - eru 4y ago
pzo 4y ago
Something doesn't sound to me quite right. If 1km2 can get you 20k L/d then 1m2 would give you 20L/d? I doubt that otherwise everyone would make their own fuel for car in small garden. Unless the actually mean 1km x 1km area.
- masklinn 4y ago
  > Unless the actually mean 1km x 1km area. Well yes, that’s what a square kilometre is. It’s (km)^2 not k(m^2). 20kL/km^2 means 20mL/m^2 (in american that’s a hair more than a tablespoon + a teaspoon).
- danw1979 4y ago
  1m2 would give 20ml per day.
- bertil 4y ago
  I haven’t check the math, but in sunny places like Nevada it is reasonable to drive an electric car that is entirely powered by solar panels on top of your garage. And run a modern house. There’s a lot of fudging factors like a tiny 1m2 panel vs. a massive 20m x 5m area, conversion efficiency, etc. but your point that “everyone would make their own fuel for car in small garden” isn’t that reasonable. Well, assuming they are not using gasoline.
  - jtc331 4y ago
    Your math is way off. A single PV produces between 300-400 watts at peak sun. It takes ~300 watt hours to drive an EV 1 mile. A very good sunny location gets 6-7 peak sun hours equivalent a day. So that one panel gets you 6-7 miles of EV range a day. A typical house needs probably 15-20 panels to produces it’s needs (assuming you have storage) before EVs are even in the picture.
    - bluGill 4y ago
      The average car goes about 40 miles per day (https://www.bts.gov/statistical-products/surveys/national-household-travel-survey-daily-travel-quick-facts https://www.bts.gov/statistical-products/surveys/national-ho...), so by your numbers only 40/6=7 panels are needed per car to charge, with some extra capacity. I think every garage as enough space on the roof for that many (per car inside), and still have extra space. Of course most cars are not at home all day, and cloudy days have to be accounted for. So we have to assume some sort of system to get around that. (the obvious ones are battery at home to charge, or sell to the grid at home and buy from the grid where you are charging) Solving these problems is not easy, but the math works out that you can do it.
ZeroGravitas 4y ago
Well if replacing the entire global jet fuel system requires more than a handful of factories, then I'm out. We'll carry on with the more than 12,000 multi-storey floating oil platforms that currently exist today that drill into the seabed instead. Having said that, just tax the externalities, and use the money to replace fossil fuels where a) it's barely an inconvenience or an actual improvement and b) it actually saves money, and lives, like EVs, and heat pumps. Carbon is fungible, the relentless focus on the hard to decorbanize sectors is just misdirection, by the time they are the only sources of fossil carbon left, they'll be simple to fix with the abundance of cheap renewable energy we've built and the money we've saved as a result.
- paganel 4y ago
  > Having said that, just tax the externalities That policy would not produce green energy that would replace the existing energy that we're now using at a societal level, it would just stop economic growth as we now understand it (mostly meaning more stuff being made, among other things). Yours is a call for more global poverty, plain and simple, which comes with its share of externalities. Case in point: make natural gas more expensive or harder to get a hold of -> price of fertilisers increases -> less agro stuff being produced -> a lot more people in the developing world getting under the extreme poverty threshold and, in the end, a lot more people dying.
  - ZeroGravitas 4y ago
    I think we're on different sides of a weird political split. We both want to help poor people in the developing world, but you're only interested in doing so if it involves giving money to fossil fuel interests. Whereas, I believe (like basically all economists do) that increasing the price of fossil fuels would actually help the world, by increasing efficiency and incentivizing better alternatives, many of which are already better than the alternatives and a net win. At least we can agree that we both want to help people, and we also agree that one of us is tragically misinformed and actively hurting the people they claim to be helping by promoting counterproductive actions. Our only point of disagreement seems to be whether it's me that's accidentally hurting people by suggesting we burn less fossil fuels, or if it's you that's hurting people by advocating for burning more fossil fuels.
titzer 4y ago
The incredible scale of our existing fossil fuel infrastructure is pretty mind-boggling, though. Apparently there are 145,000 gas stations in the United States. If someone today proposed building out an energy infrastructure that required the construction of one hundred thousand sites that each hold thousands of gallons of combustible fuel, fed by a network of trucks and pipelines from a vast array of refineries, fed by tanker trucks, extraction and drilling sites all over the planet...they would be considered nuts. The energy density for electric planes just isn't there. So we need to do something. Generating jet fuel from some carbon-neutral source is about the only sustainable path we have to keeping an airline industry going. A few thousand of these sites would be almost nothing compared to what exists.
- basilgohar 4y ago
  Yes, but there are way too many gas stations in most places – many intersections in suburban cities will have two or more gas stations at the corners, or across the street from each other. That's not due to necessity, that's just due to profit motive. There's a place near where I live where there are two Shell gas stations right across the street from each other! [0] [0] https://www.google.com/maps/search/hamilton+rd+I-70+shell+gas+station/@39.9298859,-82.879393,19.92z https://www.google.com/maps/search/hamilton+rd+I-70+shell+ga...
ur-whale 4y ago
> but it'd be quite a big endeavor to scale a facility that large. Plus you'd have to find a place that: - is politically stable - is under the rule of law - has low corruption - has lots of sunlight The Sahara desert only fits one of these constraints.
NoGravitas 4y ago
Where are the Children of Kali when you need them?

by jfim 4y ago

dredmorbius 4y ago

The vast bulk of air travel is either intranational (domestic flights) or intracontinental (as with Europe, Asia, and Africa). For both, a well-developed high-speed rail network competes exceptionally well. Short-haul flights are comparatively less efficient than long-haul as the high-energy take-off portion represents a greater fraction of total flight time. Once airborne, aircraft are remarkably efficient --- rougly on par with (single-occupant) automobile travel on a per-kilometer basis. (On a unit-time basis, of course, consumption is roughly 10x greater, and the induced travel via the Jevons paradox from reduced costs is considerable.) But developing high-speed rail networks within countries and contiguous continental regions substitutes for a huge fraction of air travel. It might also offload a considerable amount of overnight / express cargo delivery which presently moves by plane. Cargo utilisation of HSR might balance out passenger travel patterns and allow flexible capacity response to boot.

xhkkffbf 4y ago
But rail has issues of its own. The biggest may be the amount of land it takes up. While the rail lines are thin, they are very long. And if you want them to be high speed, you can't have cars crossing them. So they're very expensive to build and they require taking plenty of land out of circulation.
- dredmorbius 4y ago
  Curious fact I discovered a few years ago: land use by airports and railroads in the US is roughly the same. Airports tend to be large sprawling regions of urban land. Rail tends to be linear. I'm not sure that the comparison is entirely fair: rail accounts for a small fraction of total passenger travel (though commuter rail is a surprisingly large portion). However there's an astounding amount of freight rail. It's also possible to dual-use land near rail, especially where it counts (urbanised regions), through elevated, trenched, or subway routing. Mind, even then there may be noise and vibration issues, so you'd probably want to keep rail at some distance from residential areas, though I hear airports may have similar issues as well. Freight rail also has a history of very large switching yards in areas. Compare the CSX yards near Chicago Midway Airport. Net direct land use appears roughly comparable. https://www.openstreetmap.org/search?query=41.7813916%2C%2D87.770125#map=14/41.7814/-87.7701 https://www.openstreetmap.org/search?query=41.7813916%2C%2D8... Mind that other transport modes also have large land-use demands. Private automobiles command a third or more of all land in many cities through streets and parking.
  - xhkkffbf 4y ago
    Sure, Midway and the freight yards use about the same amount of space. The point is that the rail uses a thin strip between towns. And if a road is to cross it, you've got to build an underpass or an overpass. The topological challenges are big. Of course you're right about dual use and adjacencies and everything. It's the land between the towns that really is the issue. The airplanes are up at 30,000 feet.
    - 4y ago

41b696ef1113 4y ago

How many oil wells/barrels/square kilometers are currently dedicated to producing the world's jet fuel needs?

zachrose 4y ago
About the same amount of land. In North America alone, 30,000 square kilometers for all oil and gas[0]. For a rough approximation, the US produced 14% of oil in the world in 2021[1] and this guy on Quora[2] says that 12% of the world's oil and gas goes into aviation fuel. [0] https://www.science.org/content/article/thirty-thousand-square-kilometers-land-lost-oil-and-gas-development https://www.science.org/content/article/thirty-thousand-squa... [1] https://en.wikipedia.org/wiki/List_of_countries_by_oil_production https://en.wikipedia.org/wiki/List_of_countries_by_oil_produ... [2] https://www.quora.com/What-percentage-of-the-world-s-crude-oil-is-used-for-gasoline-diesel-and-jet-fuel https://www.quora.com/What-percentage-of-the-world-s-crude-o...
- leaflets2 4y ago
  Already pipelines running from those areas :-) maybe in the future can transport solar jet fuel instead?
- Armisael16 4y ago
  That’s all oil and gas activity; jet fuel accounts for only a very small fraction of that.
dsmmcken 4y ago
Wow, the US has just under a million operating U.S. oil and natural gas wells? That number surprised me, I don't know what I expected but I wouldn't have guessed that many. https://www.eia.gov/petroleum/wells/pdf/full_report.pdf https://www.eia.gov/petroleum/wells/pdf/full_report.pdf
- mrep 4y ago
  Well, we are the largest producer of oil in the world: https://en.wikipedia.org/wiki/List_of_countries_by_oil_production https://en.wikipedia.org/wiki/List_of_countries_by_oil_produ...

jonnycomputer 4y ago

According to [1], 8,400,000 acres have been disturbed by surface coal mining in the United States. My calculations makes that almost 34,000 square kilometers disturbed by surface coal mining. [1] https://www.gem.wiki/The_footprint_of_coal https://www.gem.wiki/The_footprint_of_coal

deleted 4y ago
[deleted]
bpodgursky 4y ago
While I am the last person to minimize how bad coal is compared to every other option, "disturbed" does not mean "blackened death, devoid of life" in most cases. There are a lot of replanted strip-mined mountains. It's not good, but does revert to nature... mostly.
- jonnycomputer 4y ago
  Point taken.
- ace2358 4y ago
  Yikes, that’s quite a bit of mental gymnastics you’re pulling there. Coal mines are horrible when they’re open and the horrible once they’re closed, don’t believe the P.R.
  - bpodgursky 4y ago
    Yes coal mines are horrible. However, reclaimed mines are not worse for the environment than literally replacing equivalent acreage with a blanket of monolithic fused-silicon solar collectors (under which, there is no environment). My point is not that coal is good, it is that the acreage comparison is not good.
    - jonnycomputer 4y ago
      What about putting solar on those old coal mines?

ETH_start 4y ago

What kind of raw materials are needed to cover 35,285 square kilometers with solar panels?

wumpus 4y ago
"Solar panels" usually means solar cells. These are mirrors.

richardw 4y ago

Sooner or later we have to price carbon externalities correctly, and fund development of offsets. It’ll be later of course, but it’s the rational course. Restating your math slightly, how can 3.5 of these be funded by a carbon fee from ~365 flights a year over 20 years? Doesn’t seem like an impossible problem to think through and at least gives us a path to a renewable cycle.

hgomersall 4y ago
My view is you should pay the cost of removing the carbon you emit. The market forces would then give a very strong incentive to both be much less carbon intensive as well as develop better co2 removal strategies.
ThomPete 4y ago
As always you need to factor in both positive and negative externalities. If you do that, the positive would still come out way way ahead. (And not it's not priced in already contrary to popular belief) The reality is that we can't sustain a civilisation of 8billion people without fossil fuels. We should do what we can to find alternatives that are less pollutant and have higher energy density but for now that means fusion, thorium and traditional fission. But we still have to solve the materials issue and we still have to content with the fact that only 20% of our energy is based on electricity and any attempt at increasing that number will require lots of fossil fuel usage as you would have to replace all the machines out there. We are going to be dependent on FF for a long long time.
- kaibee 4y ago
  > The reality is that we can't sustain a civilisation of 8billion people without fossil fuels. We should do what we can to find alternatives that are less pollutant and have higher energy density but for now that means fusion, thorium and traditional fission. This is just a failure to understand how much sunlight there is and how fast solar panels are getting cheaper.
  - ThomPete 4y ago

thatjoeoverthr 4y ago

It only really matters if any particular facility is profitable. If so, they’re will exist and supply some portion of the fuel. There isn’t any reason to think they need to supply all of it.

nicoburns 4y ago

> Back in 2017, FlightAware determined there to be an average of 9,728 commercial airplanes in the sky at any given time. Of course, that number fluctuates on a minute-by-minute basis, given that planes are nearly constantly taking off and landing. It seems unlikely that we'll be able to sustain the same level of air travel once we're no longer able to rely on cheap fossil fuels for it. I suspect air travel will get a lot more expensive and less common.

shuger 4y ago
> once we're no longer able to rely on cheap fossil fuels for it Why would that happen?
- MattPalmer1086 4y ago
  Because it becomes uneconomical to extract and process? And of course, eventually it will run out if we don't stop using it first.
  - igravious 4y ago
    That's the question: why would it become uneconomical to extract and process? https://www.worldometers.info/oil/ https://www.worldometers.info/oil/ 47 years of oil left given current reserve estimates, I'd bet my life there's a couple of centuries left at least Interesting top 11: 1 Venezuela 299,953,000,000 18.2% sanctions/attempted coup 2 Saudi Arabia 266,578,000,000 16.2% strategic ally (petrodollar) 3 Canada 170,863,000,000 10.4% neighbour 4 Iran 157,530,000,000 9.5% sanctions/coup 5 Iraq 143,069,000,000 8.7% invaded 6 Kuwait 101,500,000,000 6.1% friendly relations 7 U.A.E 97,800,000,000 5.9% friendly relations 8 Russia 80,000,000,000 4.8% sanctions/global rival 9 Libya 48,363,000,000 2.9% bombed/destabilized 10 Nigeria 37,070,000,000 2.2% friendly? 11 United States 35,230,000,000 2.1% *ahem*
    - eru 4y ago

pzo 4y ago

Something doesn't sound to me quite right. If 1km2 can get you 20k L/d then 1m2 would give you 20L/d? I doubt that otherwise everyone would make their own fuel for car in small garden. Unless the actually mean 1km x 1km area.

masklinn 4y ago
> Unless the actually mean 1km x 1km area. Well yes, that’s what a square kilometre is. It’s (km)^2 not k(m^2). 20kL/km^2 means 20mL/m^2 (in american that’s a hair more than a tablespoon + a teaspoon).
danw1979 4y ago
1m2 would give 20ml per day.
bertil 4y ago
I haven’t check the math, but in sunny places like Nevada it is reasonable to drive an electric car that is entirely powered by solar panels on top of your garage. And run a modern house. There’s a lot of fudging factors like a tiny 1m2 panel vs. a massive 20m x 5m area, conversion efficiency, etc. but your point that “everyone would make their own fuel for car in small garden” isn’t that reasonable. Well, assuming they are not using gasoline.
- jtc331 4y ago
  Your math is way off. A single PV produces between 300-400 watts at peak sun. It takes ~300 watt hours to drive an EV 1 mile. A very good sunny location gets 6-7 peak sun hours equivalent a day. So that one panel gets you 6-7 miles of EV range a day. A typical house needs probably 15-20 panels to produces it’s needs (assuming you have storage) before EVs are even in the picture.
  - bluGill 4y ago
    The average car goes about 40 miles per day (https://www.bts.gov/statistical-products/surveys/national-household-travel-survey-daily-travel-quick-facts https://www.bts.gov/statistical-products/surveys/national-ho...), so by your numbers only 40/6=7 panels are needed per car to charge, with some extra capacity. I think every garage as enough space on the roof for that many (per car inside), and still have extra space. Of course most cars are not at home all day, and cloudy days have to be accounted for. So we have to assume some sort of system to get around that. (the obvious ones are battery at home to charge, or sell to the grid at home and buy from the grid where you are charging) Solving these problems is not easy, but the math works out that you can do it.

ZeroGravitas 4y ago

Well if replacing the entire global jet fuel system requires more than a handful of factories, then I'm out. We'll carry on with the more than 12,000 multi-storey floating oil platforms that currently exist today that drill into the seabed instead. Having said that, just tax the externalities, and use the money to replace fossil fuels where a) it's barely an inconvenience or an actual improvement and b) it actually saves money, and lives, like EVs, and heat pumps. Carbon is fungible, the relentless focus on the hard to decorbanize sectors is just misdirection, by the time they are the only sources of fossil carbon left, they'll be simple to fix with the abundance of cheap renewable energy we've built and the money we've saved as a result.

paganel 4y ago
> Having said that, just tax the externalities That policy would not produce green energy that would replace the existing energy that we're now using at a societal level, it would just stop economic growth as we now understand it (mostly meaning more stuff being made, among other things). Yours is a call for more global poverty, plain and simple, which comes with its share of externalities. Case in point: make natural gas more expensive or harder to get a hold of -> price of fertilisers increases -> less agro stuff being produced -> a lot more people in the developing world getting under the extreme poverty threshold and, in the end, a lot more people dying.
- ZeroGravitas 4y ago
  I think we're on different sides of a weird political split. We both want to help poor people in the developing world, but you're only interested in doing so if it involves giving money to fossil fuel interests. Whereas, I believe (like basically all economists do) that increasing the price of fossil fuels would actually help the world, by increasing efficiency and incentivizing better alternatives, many of which are already better than the alternatives and a net win. At least we can agree that we both want to help people, and we also agree that one of us is tragically misinformed and actively hurting the people they claim to be helping by promoting counterproductive actions. Our only point of disagreement seems to be whether it's me that's accidentally hurting people by suggesting we burn less fossil fuels, or if it's you that's hurting people by advocating for burning more fossil fuels.

titzer 4y ago

The incredible scale of our existing fossil fuel infrastructure is pretty mind-boggling, though. Apparently there are 145,000 gas stations in the United States. If someone today proposed building out an energy infrastructure that required the construction of one hundred thousand sites that each hold thousands of gallons of combustible fuel, fed by a network of trucks and pipelines from a vast array of refineries, fed by tanker trucks, extraction and drilling sites all over the planet...they would be considered nuts. The energy density for electric planes just isn't there. So we need to do something. Generating jet fuel from some carbon-neutral source is about the only sustainable path we have to keeping an airline industry going. A few thousand of these sites would be almost nothing compared to what exists.

basilgohar 4y ago
Yes, but there are way too many gas stations in most places – many intersections in suburban cities will have two or more gas stations at the corners, or across the street from each other. That's not due to necessity, that's just due to profit motive. There's a place near where I live where there are two Shell gas stations right across the street from each other! [0] [0] https://www.google.com/maps/search/hamilton+rd+I-70+shell+gas+station/@39.9298859,-82.879393,19.92z https://www.google.com/maps/search/hamilton+rd+I-70+shell+ga...

ur-whale 4y ago

> but it'd be quite a big endeavor to scale a facility that large. Plus you'd have to find a place that: - is politically stable - is under the rule of law - has low corruption - has lots of sunlight The Sahara desert only fits one of these constraints.

NoGravitas 4y ago

Where are the Children of Kali when you need them?