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E-fuels are so inefficient that you need to bump carbon taxes to absurd levels before they become lucrative; it's cheaper to not ship most goods than to power s

E-fuels are so inefficient that you need to bump carbon taxes to absurd levels before they become lucrative; it's cheaper to not ship most goods than to power ships with e-fuel. It's a niche solution for niche markets - say, racecars, supercars or piston aviation - not a green transport solution. One efficient solution for marine transportation would be Hydrogen storage as Ammonia, but it requires a new engine and it's a technology that is still in its infancy. Nuclear ships and submarines exist for decades and are a workable technology. The economics might still be off, especially considering the full maintenance and decommissioning. But if there is a place to try small modular reactors that get cheaper and more reliable as they are produced in series, this is it.

pfdietz 3y ago
On the historical experience curve, electricity from PV could get so cheap that, per unit energy, it will be cheaper than thermal energy from burning natural gas. So don't presume e-fuels will stay expensive.
- goodSteveramos 3y ago
  Yes. The cool thing about efuel is that it replaces the need for both battery electric vehicles and grid storage which are incredibly expensive too. People try to compare efuel to battery electric vehicles alone but that’s not accurate.
  - Almondsetat 3y ago
    Which efuel? Surely not hydrogen since its risk of exolosion is terrifying
    - pfdietz 3y ago
      Ammonia is talked about as a fuel for ocean going ships. It's derived from hydrogen.
    - goodSteveramos 3y ago
      I think efuel refers only to synthetic hydrocarbons like gasoline not hydrogen gas or ammonia.
      - pfdietz 3y ago
        No.
        goodSteveramos 3y ago
        From Wikipedia: Electrofuels, also known as e-fuels, a class of synthetic fuels, are a type of drop-in replacement fuel. So no, neither Hydrogen gas nor amonia are drop-in replacements for gasoline or diesel fuel.
        pfdietz 3y ago
        It doesn't say what they're a replacement for in that definition. In this review article, hydrogen and ammonia are classed as e-fuels. https://ieeexplore.ieee.org/document/9837910 https://ieeexplore.ieee.org/document/9837910 > Another example is transforming electricity into e-fuels (like hydrogen) > hydrogen can be further converted to synthetic electricity-based fuels (e-fuels) as chemically bound RE and such as e-methane [27], [28], Fischer-Tropsch fuels [29], [30], e-ammonia [31], [32], and e-methanol [33], [34]. (that last paragraph doesn't say hydrogen is not an e-fuel, it says it's not a "synthetic" e-fuel, as hydrogen is as feedstock for synthesis here.)
- vlovich123 3y ago
  You’re suggesting powering large tankers using PV cells? I think it’s less about cost and more that there’s insufficient power density to power a tanker. Hydrogen fuel is probably the only way to do that and you’d probably need a nuclear plant close to ports generating it on demand because hydrogen is energy intensive to create and supremely difficult to store (+ storage would still be a problem on ships and massive explosions would be a real risk)
  - aaronblohowiak 3y ago
    PV cells on land overproducing leading to 0 or negative electricity prices, upturning the economics of using electricity for hydrolysis -based fuels, iiuc
  - epistasis 3y ago
    The suggestion is that electricity from PV could be so cheap that generating fuels with electricity could be cheaper, even with the massive inefficiency of it. It won't be hydrogen, because hydrogen is volumetrically not dense enough, it would likely be something like methanol or methane or maybe, with the right tech breakthrough, longer chains of carbon. You definitely don't want a nuclear plant generating this, because nuclear is way too expensive. Today, right now, solar energy stored in batteries is cheaper than new nuclear. And every year that price falls further. And most of the energy would never even have to be stored in batteries, and PV is cheaper than operating already-paid-for natural gas generators in most markets right now, (and getting cheaper). The energy world is being disrupted, but the incumbents aren't paying attention, and most of the US media is devoted to covering it up and discrediting cheaper energy, to benefit incumbent fossil fuel energy companies, the ones buying lots of advertisements.
    - pfdietz 3y ago
      Carbon-containing fuels have the problem of either requiring CO2 to be retained on the ship for regeneration, or capture of CO2 from air to close the cycle. I wonder if metal e-fuels like, say, magnesium could be used. These might be more compatible with direct conversion of chemical energy to electrical energy. Oxidized magnesium could be directly released into the ocean to help reduce its pH. More aggressively: sodium?
ZeroGravitas 3y ago
Big names in shipping (shipbuilders, shipping, big customers) have already committed to efuels like green methanol. The ships are rolling off the production line now, the big task is a massive (massive!) ramp up of production of fuels to fill them. Carbon and other pollution fees are part of the solution to kick the market off, but again they're already in place (and would help nuclear powered ships equally)
IshKebab 3y ago
I think you're right but I got curious about the numbers: > 48% of renewable electricity used to convert e-fuels into liquid is lost along the process, while up to 70% of the fuel's energy is lost upon combustion. Not as bad as I thought tbh.

pfdietz 3y ago

On the historical experience curve, electricity from PV could get so cheap that, per unit energy, it will be cheaper than thermal energy from burning natural gas. So don't presume e-fuels will stay expensive.

goodSteveramos 3y ago
Yes. The cool thing about efuel is that it replaces the need for both battery electric vehicles and grid storage which are incredibly expensive too. People try to compare efuel to battery electric vehicles alone but that’s not accurate.
- Almondsetat 3y ago
  Which efuel? Surely not hydrogen since its risk of exolosion is terrifying
  - pfdietz 3y ago
    Ammonia is talked about as a fuel for ocean going ships. It's derived from hydrogen.
  - goodSteveramos 3y ago
    I think efuel refers only to synthetic hydrocarbons like gasoline not hydrogen gas or ammonia.
    - pfdietz 3y ago
      No.
      - goodSteveramos 3y ago
        From Wikipedia: Electrofuels, also known as e-fuels, a class of synthetic fuels, are a type of drop-in replacement fuel. So no, neither Hydrogen gas nor amonia are drop-in replacements for gasoline or diesel fuel.
        pfdietz 3y ago
        It doesn't say what they're a replacement for in that definition. In this review article, hydrogen and ammonia are classed as e-fuels. https://ieeexplore.ieee.org/document/9837910 https://ieeexplore.ieee.org/document/9837910 > Another example is transforming electricity into e-fuels (like hydrogen) > hydrogen can be further converted to synthetic electricity-based fuels (e-fuels) as chemically bound RE and such as e-methane [27], [28], Fischer-Tropsch fuels [29], [30], e-ammonia [31], [32], and e-methanol [33], [34]. (that last paragraph doesn't say hydrogen is not an e-fuel, it says it's not a "synthetic" e-fuel, as hydrogen is as feedstock for synthesis here.)
vlovich123 3y ago
You’re suggesting powering large tankers using PV cells? I think it’s less about cost and more that there’s insufficient power density to power a tanker. Hydrogen fuel is probably the only way to do that and you’d probably need a nuclear plant close to ports generating it on demand because hydrogen is energy intensive to create and supremely difficult to store (+ storage would still be a problem on ships and massive explosions would be a real risk)
- aaronblohowiak 3y ago
  PV cells on land overproducing leading to 0 or negative electricity prices, upturning the economics of using electricity for hydrolysis -based fuels, iiuc
- epistasis 3y ago
  The suggestion is that electricity from PV could be so cheap that generating fuels with electricity could be cheaper, even with the massive inefficiency of it. It won't be hydrogen, because hydrogen is volumetrically not dense enough, it would likely be something like methanol or methane or maybe, with the right tech breakthrough, longer chains of carbon. You definitely don't want a nuclear plant generating this, because nuclear is way too expensive. Today, right now, solar energy stored in batteries is cheaper than new nuclear. And every year that price falls further. And most of the energy would never even have to be stored in batteries, and PV is cheaper than operating already-paid-for natural gas generators in most markets right now, (and getting cheaper). The energy world is being disrupted, but the incumbents aren't paying attention, and most of the US media is devoted to covering it up and discrediting cheaper energy, to benefit incumbent fossil fuel energy companies, the ones buying lots of advertisements.
  - pfdietz 3y ago
    Carbon-containing fuels have the problem of either requiring CO2 to be retained on the ship for regeneration, or capture of CO2 from air to close the cycle. I wonder if metal e-fuels like, say, magnesium could be used. These might be more compatible with direct conversion of chemical energy to electrical energy. Oxidized magnesium could be directly released into the ocean to help reduce its pH. More aggressively: sodium?

ZeroGravitas 3y ago

Big names in shipping (shipbuilders, shipping, big customers) have already committed to efuels like green methanol. The ships are rolling off the production line now, the big task is a massive (massive!) ramp up of production of fuels to fill them. Carbon and other pollution fees are part of the solution to kick the market off, but again they're already in place (and would help nuclear powered ships equally)

IshKebab 3y ago

I think you're right but I got curious about the numbers: > 48% of renewable electricity used to convert e-fuels into liquid is lost along the process, while up to 70% of the fuel's energy is lost upon combustion. Not as bad as I thought tbh.