7 ms·

What are some applications where its worth taking the highest grade energy (electricity) and turning it into a lower grade (eg liquid fuels), rather than electr

What are some applications where its worth taking the highest grade energy (electricity) and turning it into a lower grade (eg liquid fuels), rather than electrifying the application? Electricity to motion is significantly more efficient per input energy than burning fuel->heat-> gaseous expansion->drive a piston->convert to rotation chain. What am I missing about this?

Loggias 3y ago
[dead]
rini17 3y ago
Seasonal storage. Large amounts of gas can be stored underground.
DenseComet 3y ago
Energy density is much higher, which is important for applications such as aviation.
dr_kretyn 3y ago
Lack of sockets is likely the main one. Then, lack of the long long cable to the nearest socket.
megaman821 3y ago
Seasonal storage of energy is likely only practical in fuel form. Also, there is no easy pathway to electricity to high temperature heat.
- maerF0x0 3y ago
  I'm guessing you mean high temperature + high energy (ie lots of watts). Cause lasers can do high temp rn, right?
  - trueismywork 3y ago
    Yes
spenczar5 3y ago
You’re missing density of storage. Gasoline and natural gas are in the region of 50 MJ/kg, while batteries are more like 10MJ/kg or lower. That 5x factor is what stops us from having electric airplanes.
- timerol 3y ago
  10 MJ/kg is way overstated for batteries. Current Li-ion is around 1 MJ/kg (278 Wh/kg)
- maerF0x0 3y ago
  I actually think the reason we don't have electric airplanes has to do with traction vs propulsion. Eg: spinning a jet engine to propel air backwards is very different than spinning a motor that is (through a series of solid objects) directly connect to the ground. and while a battery is only 1/5th density, the motors on a tesla deliver 3x the range per energy compared to a prius. (not true break even, but impressive that one of the most efficient hybrid ICE cannot compare KWh for KWh to a battery + electric)
  - XorNot 3y ago
    No it's just energy density. Hydrocarbon fuels have more. There's also the benefit that getting lighter as you expend fuel increases range (batteries don't meaningfully change mass when they discharge). Nothing about electric powertrains causes any problems here: it's just hydrocarbon fuel is more energy dense. It's not inconceivable you could build a hybrid electric aircraft if a suitably high power hydrocarbon fuel cell was developed, since removing the combustion stages from a jet engine would simplify the design considerably.
abdullahkhalids 3y ago
The only way a technology like this will help get us to carbon zero is using it in places where there is not much hope of replacing electricity. While small elective airplanes have been demonstrated, it doesn't seem like we will be able to build, in the next couple of decades, large electric airplanes that can substantially replace current fuel powered ones. This would require the additional step of converting methane to jet fuel, but that is also a technology under development. That said, I personally think, in practice technology like this will only delay getting to net zero, because the existence of this will disincentivize investments in electrification. I recall Sun Tzu's claim that a force completely surrounded will fight fiercely, but if you give a way out, it will look to escape or retreat.
- DarmokJalad1701 3y ago
  You could theoretically run jet engines on directly on methane (liquid or not) - though I am not sure how much work would be required to refit an existing one for this purpose. Methane is already used for running the turbo-pumps in rocket engines like SpaceX's Raptor or Relativity's Aeon-R.
  - Plasmoid 3y ago
    You'd be talking about liquid methane to get the energy density you want. Handling a cryofuel would be quite hard and you'd be redesigning everything to ensure it kept working.
- trueismywork 3y ago
  Electricity/energy consumption of developing world is going to be at least twice today's value. Better this than coal
- orr94 3y ago
  > I personally think, in practice technology like this will only delay getting to net zero, because the existence of this will disincentivize investments in electrification. I recall Sun Tzu's claim that a force completely surrounded will fight fiercely, but if you give a way out, it will look to escape or retreat. I think you’re misapplying Sun Tzu’s lesson. An attempt to completely and immediately replace the fossil fuel industry will be met with fierce resistance, and thus be more likely to fail. Whereas a more gradual approach (like carbon neutral-ish green hydrogen) gives much of the industry around fossil fuels an opportunity to survive longer, and perhaps gives you a better chance of success. Is this actually true? Maybe, maybe not. But that would seem to be the implication of Sun Tzu’s strategy.
OkayPhysicist 3y ago
Chemical fuels are dramatically easier to store and transport than electricity. Batteries are heavy and expensive compared to a tank. Time-dependent surplus electricity (which is basically a guaranteed situation on renewable-heavy grids) is basically free, which makes efficiency concerns approximately moot. Instead of letting excess capacity go to waste, you use it to create chemical fuel, which can be used either just as storage to be later burned in a peaker plant, or you can use it as fuel in mobile settings (trucks, planes, ships, etc) where energy density is important.
shawndrost 3y ago
Electricity (during sunlight hours) is not the highest grade of energy. California threw away ~32TWh of electricity last year, with renewables at only 19% penetration. You can't give power away at noon in April; this fact is a significant barrier to building new solar. (See "Learning is not enough" and other academic research on that topic.) We also use fossil fuels as feedstocks for fertilizers and plastics, so there are very important power-to-X applications which don't involve inefficient combustion. Something like Terraform would probably have to exist in order to transition away from fossil fuels. (Source: I'm CEO at a startup with a very different take on the same problem.)
- boringg 3y ago
  So the argument is take excess solar power turn it into a fuel for use at another time. It's another take on energy storage. Question for me is how do you make the business model work. Is it a bet that lower cost to produce or bank that carbon tax on traditional fuels makes it more cost competitive? Or in your case is it that downstream users are looking to clean up their supply chain so will look into a contract for that benefit? To your point everything can't be electricity or alternatively fuels have different use cases. And it's certainly important to have a diversity of power sources especially as fuel has different attributes then electricity.
  - EasyMark 3y ago
    we aren't very good at storing electrical energy just yet, but we have a couple hundred years of experience storing and using hydrocarbons. I'm sure you can read the pdf someone posted up above and get their take on it.
  - gimmeThaBeet 3y ago
    Exactly, the tl;dr is energy storage, but I feel like it's sort of the Amazon approach. There was an interview where they asked Bezos why books as Amazon's first product, and his answer was basically: "I read internet usage was going up by 2300 percent a year, so I decided to try and find a business that would make sense in that context." "Cheap and ubiquitous solar power is coming, what products does the world need in that context to move away from extracting fossil fuels?" Like a lot of things, current technology probably isn't there yet. But philosophically, if you wait for tech to catch up with your vision of the future, you might find yourself behind.
yodelshady 3y ago
There are ships that move over one billion kWh of LNG around at a time. At $100 to store a kWh of electrical energy, along with approximately ten times the cost to account for structures that can support and move the extra weight (that's AFTER allowing for less energy demanded in total)... shall I leave this as exercise to the reader?
- maerF0x0 3y ago
  Ok, so here you're referring to moving a lot of energy w/o wires/transmission lines? Is that a commonly needed thing?
  - Danieru 3y ago
    South Korea, Japan, China say hello. Much of the world by population and gdp is a ship ride away from their major energy suppliers. Japan imports about half their LNG from Australia. Next largest is Qatar. There are no power lines between Australia and Japan.
    - maerF0x0 3y ago
      Right, but why rely on LNG when Nuclear sources could provide so much more energy and geo-political stability, and promising investment in other avenues (eg Thorium based) could make it even moreso?
      - bryanlarsen 3y ago
        Nuclear is better in many ways. It's a shame it costs an order of magnitude more than alternatives.
        maerF0x0 3y ago
        Interesting point, A quick google suggests both possibilities that solar and nuclear are each cheaper depending on how big of a picture you're looking. (Capital, construction, storage for solar cause nuclear can run at night, storage for 25000 years for the waste etc). Still, if moving a lot of (potential) heat energy from point to point is the goal, Uranium still seems to be the move compared to so many tankers of LNG -- just to burn it. Nuclear plants put off a ton of waste heat energy, and it can be at a very high temperature too (if designed and desired).
michael1999 3y ago
- heating a zillion legacy homes using existing gas pipelines - running all the existing fertilizer and other chemical plants - gas peakers/backups for resiliency. Gas storage is much cheaper than batteries. Even if all new construction is electric, we have decades of infrastructure built around gas. Replacing the furnace in every German house with a heat pump just isn't going to happen in 10 years.
- maerF0x0 3y ago
  > - heating a zillion legacy homes using existing gas pipelines They dont have electricity to heat with? > - running all the existing fertilizer and other chemical plants This takes hydrogen gas from the nat gas, why not just use the electricity for hydrolysis I think other commenters have said it well. It's really just a storage mechanism. Waste daytime solar for use at non-peak solar production
  - michael1999 3y ago
    Half of German homes use gas heat. Replacing half the furnaces in Germany will take a loooong time. My point isn't efficiency, but the size of the installed plant. I fully expect new infrastructure will use more electricity. But we have accumulated trillions of dollars of infrastructure using natural gas over more than a century. There is absolutely no way we are going to replace it all in 10 years.
marcosdumay 3y ago
If you are talking about thermodynamics, chemical energy is exactly of the same grade as electricity.
- maerF0x0 3y ago
  No thermodynamics. Like usefulness. Electricity can be uses for a lot of things. a mass heated to 50c is not, relatively, as useful. Plus low temp waste heat is abundant eg: from computing, or refrigeration, or exhaust pipes of engines.
usrusr 3y ago
Time travel. It's very expensive to move electricity into the future. Batteries are very cheap when you look at dollars per watt of onboarding/offboarding the one way time machine, but when you look at it dollars per Wh it does not look as rosy anymore. Still worthwhile for short hops. But for longer trips, you want to look at $/Whh and then batteries are atrociously expensive. Seasons are a thing and time travel is hard, even if it's only one way.
fransje26 3y ago
Applications that need heat. Metallurgy, for instance.
- pbmonster 3y ago
  You can actually electrify much of metallurgy, and this is already happening. Things like cement kilns are much more difficult, on the other hand.

Loggias 3y ago

[dead]

rini17 3y ago

Seasonal storage. Large amounts of gas can be stored underground.

DenseComet 3y ago

Energy density is much higher, which is important for applications such as aviation.

dr_kretyn 3y ago

Lack of sockets is likely the main one. Then, lack of the long long cable to the nearest socket.

megaman821 3y ago

Seasonal storage of energy is likely only practical in fuel form. Also, there is no easy pathway to electricity to high temperature heat.

maerF0x0 3y ago
I'm guessing you mean high temperature + high energy (ie lots of watts). Cause lasers can do high temp rn, right?
- trueismywork 3y ago
  Yes

spenczar5 3y ago

You’re missing density of storage. Gasoline and natural gas are in the region of 50 MJ/kg, while batteries are more like 10MJ/kg or lower. That 5x factor is what stops us from having electric airplanes.

timerol 3y ago
10 MJ/kg is way overstated for batteries. Current Li-ion is around 1 MJ/kg (278 Wh/kg)
maerF0x0 3y ago
I actually think the reason we don't have electric airplanes has to do with traction vs propulsion. Eg: spinning a jet engine to propel air backwards is very different than spinning a motor that is (through a series of solid objects) directly connect to the ground. and while a battery is only 1/5th density, the motors on a tesla deliver 3x the range per energy compared to a prius. (not true break even, but impressive that one of the most efficient hybrid ICE cannot compare KWh for KWh to a battery + electric)
- XorNot 3y ago
  No it's just energy density. Hydrocarbon fuels have more. There's also the benefit that getting lighter as you expend fuel increases range (batteries don't meaningfully change mass when they discharge). Nothing about electric powertrains causes any problems here: it's just hydrocarbon fuel is more energy dense. It's not inconceivable you could build a hybrid electric aircraft if a suitably high power hydrocarbon fuel cell was developed, since removing the combustion stages from a jet engine would simplify the design considerably.

abdullahkhalids 3y ago

The only way a technology like this will help get us to carbon zero is using it in places where there is not much hope of replacing electricity. While small elective airplanes have been demonstrated, it doesn't seem like we will be able to build, in the next couple of decades, large electric airplanes that can substantially replace current fuel powered ones. This would require the additional step of converting methane to jet fuel, but that is also a technology under development. That said, I personally think, in practice technology like this will only delay getting to net zero, because the existence of this will disincentivize investments in electrification. I recall Sun Tzu's claim that a force completely surrounded will fight fiercely, but if you give a way out, it will look to escape or retreat.

DarmokJalad1701 3y ago
You could theoretically run jet engines on directly on methane (liquid or not) - though I am not sure how much work would be required to refit an existing one for this purpose. Methane is already used for running the turbo-pumps in rocket engines like SpaceX's Raptor or Relativity's Aeon-R.
- Plasmoid 3y ago
  You'd be talking about liquid methane to get the energy density you want. Handling a cryofuel would be quite hard and you'd be redesigning everything to ensure it kept working.
trueismywork 3y ago
Electricity/energy consumption of developing world is going to be at least twice today's value. Better this than coal
orr94 3y ago
> I personally think, in practice technology like this will only delay getting to net zero, because the existence of this will disincentivize investments in electrification. I recall Sun Tzu's claim that a force completely surrounded will fight fiercely, but if you give a way out, it will look to escape or retreat. I think you’re misapplying Sun Tzu’s lesson. An attempt to completely and immediately replace the fossil fuel industry will be met with fierce resistance, and thus be more likely to fail. Whereas a more gradual approach (like carbon neutral-ish green hydrogen) gives much of the industry around fossil fuels an opportunity to survive longer, and perhaps gives you a better chance of success. Is this actually true? Maybe, maybe not. But that would seem to be the implication of Sun Tzu’s strategy.

OkayPhysicist 3y ago

Chemical fuels are dramatically easier to store and transport than electricity. Batteries are heavy and expensive compared to a tank. Time-dependent surplus electricity (which is basically a guaranteed situation on renewable-heavy grids) is basically free, which makes efficiency concerns approximately moot. Instead of letting excess capacity go to waste, you use it to create chemical fuel, which can be used either just as storage to be later burned in a peaker plant, or you can use it as fuel in mobile settings (trucks, planes, ships, etc) where energy density is important.

shawndrost 3y ago

Electricity (during sunlight hours) is not the highest grade of energy. California threw away ~32TWh of electricity last year, with renewables at only 19% penetration. You can't give power away at noon in April; this fact is a significant barrier to building new solar. (See "Learning is not enough" and other academic research on that topic.) We also use fossil fuels as feedstocks for fertilizers and plastics, so there are very important power-to-X applications which don't involve inefficient combustion. Something like Terraform would probably have to exist in order to transition away from fossil fuels. (Source: I'm CEO at a startup with a very different take on the same problem.)

boringg 3y ago
So the argument is take excess solar power turn it into a fuel for use at another time. It's another take on energy storage. Question for me is how do you make the business model work. Is it a bet that lower cost to produce or bank that carbon tax on traditional fuels makes it more cost competitive? Or in your case is it that downstream users are looking to clean up their supply chain so will look into a contract for that benefit? To your point everything can't be electricity or alternatively fuels have different use cases. And it's certainly important to have a diversity of power sources especially as fuel has different attributes then electricity.
- EasyMark 3y ago
  we aren't very good at storing electrical energy just yet, but we have a couple hundred years of experience storing and using hydrocarbons. I'm sure you can read the pdf someone posted up above and get their take on it.
- gimmeThaBeet 3y ago
  Exactly, the tl;dr is energy storage, but I feel like it's sort of the Amazon approach. There was an interview where they asked Bezos why books as Amazon's first product, and his answer was basically: "I read internet usage was going up by 2300 percent a year, so I decided to try and find a business that would make sense in that context." "Cheap and ubiquitous solar power is coming, what products does the world need in that context to move away from extracting fossil fuels?" Like a lot of things, current technology probably isn't there yet. But philosophically, if you wait for tech to catch up with your vision of the future, you might find yourself behind.

yodelshady 3y ago

There are ships that move over one billion kWh of LNG around at a time. At $100 to store a kWh of electrical energy, along with approximately ten times the cost to account for structures that can support and move the extra weight (that's AFTER allowing for less energy demanded in total)... shall I leave this as exercise to the reader?

maerF0x0 3y ago
Ok, so here you're referring to moving a lot of energy w/o wires/transmission lines? Is that a commonly needed thing?
- Danieru 3y ago
  South Korea, Japan, China say hello. Much of the world by population and gdp is a ship ride away from their major energy suppliers. Japan imports about half their LNG from Australia. Next largest is Qatar. There are no power lines between Australia and Japan.
  - maerF0x0 3y ago
    Right, but why rely on LNG when Nuclear sources could provide so much more energy and geo-political stability, and promising investment in other avenues (eg Thorium based) could make it even moreso?
    - bryanlarsen 3y ago
      Nuclear is better in many ways. It's a shame it costs an order of magnitude more than alternatives.
      - maerF0x0 3y ago
        Interesting point, A quick google suggests both possibilities that solar and nuclear are each cheaper depending on how big of a picture you're looking. (Capital, construction, storage for solar cause nuclear can run at night, storage for 25000 years for the waste etc). Still, if moving a lot of (potential) heat energy from point to point is the goal, Uranium still seems to be the move compared to so many tankers of LNG -- just to burn it. Nuclear plants put off a ton of waste heat energy, and it can be at a very high temperature too (if designed and desired).

michael1999 3y ago

- heating a zillion legacy homes using existing gas pipelines - running all the existing fertilizer and other chemical plants - gas peakers/backups for resiliency. Gas storage is much cheaper than batteries. Even if all new construction is electric, we have decades of infrastructure built around gas. Replacing the furnace in every German house with a heat pump just isn't going to happen in 10 years.

maerF0x0 3y ago
> - heating a zillion legacy homes using existing gas pipelines They dont have electricity to heat with? > - running all the existing fertilizer and other chemical plants This takes hydrogen gas from the nat gas, why not just use the electricity for hydrolysis I think other commenters have said it well. It's really just a storage mechanism. Waste daytime solar for use at non-peak solar production
- michael1999 3y ago
  Half of German homes use gas heat. Replacing half the furnaces in Germany will take a loooong time. My point isn't efficiency, but the size of the installed plant. I fully expect new infrastructure will use more electricity. But we have accumulated trillions of dollars of infrastructure using natural gas over more than a century. There is absolutely no way we are going to replace it all in 10 years.

marcosdumay 3y ago

If you are talking about thermodynamics, chemical energy is exactly of the same grade as electricity.

maerF0x0 3y ago
No thermodynamics. Like usefulness. Electricity can be uses for a lot of things. a mass heated to 50c is not, relatively, as useful. Plus low temp waste heat is abundant eg: from computing, or refrigeration, or exhaust pipes of engines.

usrusr 3y ago

Time travel. It's very expensive to move electricity into the future. Batteries are very cheap when you look at dollars per watt of onboarding/offboarding the one way time machine, but when you look at it dollars per Wh it does not look as rosy anymore. Still worthwhile for short hops. But for longer trips, you want to look at $/Whh and then batteries are atrociously expensive. Seasons are a thing and time travel is hard, even if it's only one way.

fransje26 3y ago

Applications that need heat. Metallurgy, for instance.

pbmonster 3y ago
You can actually electrify much of metallurgy, and this is already happening. Things like cement kilns are much more difficult, on the other hand.