7 ms·

Beyond the missing expensive infrastructure, the big problem is energy efficiency. Moving forward, we have to switch every energy production to renewables. But

by _ph_ 5y ago

Beyond the missing expensive infrastructure, the big problem is energy efficiency. Moving forward, we have to switch every energy production to renewables. But for the same amount of electric energy produced, an electric car gets about 3x the mileage than producing "green" hydrogen and powering fuel cell cars with it. Hydrogen means at least 3x the electricity cost and for many years to come, we are going to struggle producing enough clean electricity in the first place. Also the infrastructure for electricity basically is there, mostly needed are plain outlets at all long-term parking spots. And of course, one can charge an electric car from your own solar.

JPKab 5y ago
The key to a hydrogen economy will rely on creation of hydrogen in locations with extremely abundant electricity like Iceland. The next step is shipping it like it's LNG. Not a small order.
- danogentili 5y ago
  > The key to a hydrogen economy will rely on wasting energy on creation of hydrogen in locations with extremely abundant electricity. Honestly, this sounds just as bad as setting up bitcoin mines in places with high rates of renewables, to avoid directly throwing tons of CO2 in the atmosphere. Even if you have loads of clean energy, that's no reason to waste it when there are more efficient ways of using it (lithium batteries, PoS). Not to mention the fact that every watt of wasted green energy can't used to replace a watt of coal energy.
  - JPKab 5y ago
    I don't think there's a scarcity issue with electricity in places like Iceland where volcanic activity provides massive areas of land where electricity can be freely and easily generated. The issue is the ability to transport said electricity without massive losses.
  - mminer237 5y ago
    I don't think you can feasibly ship all your electric batteries to be charged up in Iceland.
    - kwhitefoot 5y ago
      > don't think you can feasibly ship all your electric batteries to be charged up in Iceland. No need if the Icelink DC link gets built. https://en.wikipedia.org/wiki/Icelink https://en.wikipedia.org/wiki/Icelink
- _ph_ 5y ago
  Yes, those locations will play a huge role in securing the global energy supply. However, the hydrogen will be desperately needed in the industry (e.g. steel production) and for supporting the electric grid in times of both low wind and solar. No good reason to waste it around the year driving cars.
  - olivermarks 5y ago
    My understanding is that hydrogen may be most useful for heavy good vehicles rather than cars. EVs could be great for short range urban delivery vans etc but long haul infrastructure may be built around hydrogen if the supply chain is viable.
    - _ph_ 5y ago
      Might, but if the Tesla Semi becomes a reality, the potential market for hydrogen in trucks becomes much smaller too.
      - olivermarks 5y ago
        The dynamics of moving heavy loads long distances has never favored electric power. Diesel currently powers tractor semis because it produces more energy than gasoline and creates much more low speed continuous load torque. EVs are well suited to light loads and short distances, rapid acceleration and altitude change but are not well suited to long range hauling of heavy loads due to the enormous energy required.
        _ph_ 5y ago
        EVs are great if you are pulling heavy loads across hills, as you get your energy back going downhill (at least large parts of it). The torque also rather is an advantage of EVs. Diesel engines are popular because they are more efficient than gasoline engines and if you have continuous high loads, that adds up. Guess what is much more efficient than Diesel engines? Electric engines! And they are way more efficient than going the route via hydrogen. The only open question is: can you put enough batteries into a battery electric semi? If you can't, then of course the question about efficiency is moot. But if you can, everything speaks for battery electric vehicles. That is where the Tesla Semi comes into play. It promises ranges that are just enough for most applications, for those applications it has basically "won" right from the start. What remains to be seen is how large exactly the sector is which isn't served by the Semi. But in any case, with every improvement of the battery technology, that sector shrinks a bit further.
- grogenaut 5y ago
  Do you mean similar to how we do the same with LNG or oil from Alaska?
konschubert 5y ago
The bottleneck is not kwh of electricity produced, but storage. Hydrogen cards do well on that bottleneck.
- _ph_ 5y ago
  No, the do worse than electric cars in that respect. The hydrogen production facilities are very expensive, so they have to run 24/7 at the same load. This is exactly what mixed badly with the varying supply of renewables. With electric cars, you just plug them in at home/at work and they charge whenever there is an oversupply of electricity. Offering special remote controlled charging outlets is going to be a game changer for the grid.
- donkeyd 5y ago
  If I were to store solar in my electric car as a form of temporary storage, I get probably between 80 and 90% of what was generated by my cells delivered back to my house. All I need to do this are some slight alterations to my electrical system. If I wanted to do this with my hydrogen car, I would need to get some expensive electrolysis station next to my house and I would get maybe 50% of stored energy back after electrolysis. I would also need to get the compressor etc maintained regularly. Also, if you mean storage for actual driving, as in possible range, there's hardly a need for more range than a Tesla can already deliver... For most people. The biggest change to make it more feasible for pretty much all people is charging speed and that keeps improving too.
  - eloff 5y ago
    Tesla doesn't allow this because of the wear on the batteries, but it seems like a killer application for EVs and rooftop solar to be able to combine them like that.
grogenaut 5y ago
I enjoy how you are taking all of the arguments people used against BEVs in favor of gas and using them against HV. The irony is strong in these threads.
- _ph_ 5y ago
  Sorry, I don't get what you mean. Which arguments are you referring to and what is ironic?
- DeRock 5y ago
  BEVs are much more energy efficient than ICE. When was the argument that they are not ever used?
Mvandenbergh 5y ago
The question is not whether you pay a massive efficiency penalty for storing electricity as hydrogen (obviously, yes) but whether there are applications where you are effectively buying a set of useful properties for the losses you are "spending". For displacing existing grey hydrogen from the chemical industry, a possible reducing agent in steel making, and other high temperature industrial processes it's pretty clear that the answer will be yes. I happen to think that it is really unlikely that the answer for cars and vans will ever be yes, even if hydrogen could be made cheaply. Whether it will have a role in other applications depends on a few things: First, the structure of the future electricity mix. In order to ensure that there is enough electricity at every moment, we have to do a mix of things: -"over" build variable output renewables so that the troughs in production are higher -Intra-day demand side response -Intra-day storage (almost certainly batteries) -Dispatchable renewables like hydro -Dispatchable sort-of renewables based on biomass -Dispatchable fossil fuels (with CCS) -Load-following nuclear The reason why people think about hydrogen and other exotic technologies is that many of the technologies on that list either have limited available scope (hydro, biomass), are probably not really carbon-neutral (biomass, CCS), rely on unproven tech at scale (CCS, new nuclear designs), or have exceptionally high capital costs (any new nuclear but especially when at low load factors, CCS especially at low load factors). So what most simulations show you're left with as a low-cost mix for most days is a combination of the first five. That still leaves you with two problems: -What do you do if the average output net of load is very different between seasons? -How do you provision for a 1:20 yr weather system without making your system vastly more expensive? and one opportunity (which is also a challenge): -variable renewables are cheap and getting cheaper so cost-optimal generation mixes build a lot more than needed for the average day in order to keep use of expensive biomass and limited hydro capacity to a minimum. As a result, electricity has low/no marginal value a lot of the time. Second, the future cost of electrolysers. At current capex levels, they need to be run at max load all the time and still produce expensive hydrogen. Genuinely low costs like what BNEF thinks might be possible ($100/kW) allow you to run for only 20% or less of the hours in the year and scoop all the excess electricity up. Third, the cost of alternative solutions in the areas where hydrogen is currently being considered as this reduces the value of any hydrogen produced. I do agree that for passenger cars it's just not going to happen.

by _ph_ 5y ago

JPKab 5y ago

The key to a hydrogen economy will rely on creation of hydrogen in locations with extremely abundant electricity like Iceland. The next step is shipping it like it's LNG. Not a small order.

danogentili 5y ago
> The key to a hydrogen economy will rely on wasting energy on creation of hydrogen in locations with extremely abundant electricity. Honestly, this sounds just as bad as setting up bitcoin mines in places with high rates of renewables, to avoid directly throwing tons of CO2 in the atmosphere. Even if you have loads of clean energy, that's no reason to waste it when there are more efficient ways of using it (lithium batteries, PoS). Not to mention the fact that every watt of wasted green energy can't used to replace a watt of coal energy.
- JPKab 5y ago
  I don't think there's a scarcity issue with electricity in places like Iceland where volcanic activity provides massive areas of land where electricity can be freely and easily generated. The issue is the ability to transport said electricity without massive losses.
- mminer237 5y ago
  I don't think you can feasibly ship all your electric batteries to be charged up in Iceland.
  - kwhitefoot 5y ago
    > don't think you can feasibly ship all your electric batteries to be charged up in Iceland. No need if the Icelink DC link gets built. https://en.wikipedia.org/wiki/Icelink https://en.wikipedia.org/wiki/Icelink
_ph_ 5y ago
Yes, those locations will play a huge role in securing the global energy supply. However, the hydrogen will be desperately needed in the industry (e.g. steel production) and for supporting the electric grid in times of both low wind and solar. No good reason to waste it around the year driving cars.
- olivermarks 5y ago
  My understanding is that hydrogen may be most useful for heavy good vehicles rather than cars. EVs could be great for short range urban delivery vans etc but long haul infrastructure may be built around hydrogen if the supply chain is viable.
  - _ph_ 5y ago
    Might, but if the Tesla Semi becomes a reality, the potential market for hydrogen in trucks becomes much smaller too.
    - olivermarks 5y ago
      The dynamics of moving heavy loads long distances has never favored electric power. Diesel currently powers tractor semis because it produces more energy than gasoline and creates much more low speed continuous load torque. EVs are well suited to light loads and short distances, rapid acceleration and altitude change but are not well suited to long range hauling of heavy loads due to the enormous energy required.
      - _ph_ 5y ago
        EVs are great if you are pulling heavy loads across hills, as you get your energy back going downhill (at least large parts of it). The torque also rather is an advantage of EVs. Diesel engines are popular because they are more efficient than gasoline engines and if you have continuous high loads, that adds up. Guess what is much more efficient than Diesel engines? Electric engines! And they are way more efficient than going the route via hydrogen. The only open question is: can you put enough batteries into a battery electric semi? If you can't, then of course the question about efficiency is moot. But if you can, everything speaks for battery electric vehicles. That is where the Tesla Semi comes into play. It promises ranges that are just enough for most applications, for those applications it has basically "won" right from the start. What remains to be seen is how large exactly the sector is which isn't served by the Semi. But in any case, with every improvement of the battery technology, that sector shrinks a bit further.
grogenaut 5y ago
Do you mean similar to how we do the same with LNG or oil from Alaska?

konschubert 5y ago

The bottleneck is not kwh of electricity produced, but storage. Hydrogen cards do well on that bottleneck.

_ph_ 5y ago
No, the do worse than electric cars in that respect. The hydrogen production facilities are very expensive, so they have to run 24/7 at the same load. This is exactly what mixed badly with the varying supply of renewables. With electric cars, you just plug them in at home/at work and they charge whenever there is an oversupply of electricity. Offering special remote controlled charging outlets is going to be a game changer for the grid.
donkeyd 5y ago
If I were to store solar in my electric car as a form of temporary storage, I get probably between 80 and 90% of what was generated by my cells delivered back to my house. All I need to do this are some slight alterations to my electrical system. If I wanted to do this with my hydrogen car, I would need to get some expensive electrolysis station next to my house and I would get maybe 50% of stored energy back after electrolysis. I would also need to get the compressor etc maintained regularly. Also, if you mean storage for actual driving, as in possible range, there's hardly a need for more range than a Tesla can already deliver... For most people. The biggest change to make it more feasible for pretty much all people is charging speed and that keeps improving too.
- eloff 5y ago
  Tesla doesn't allow this because of the wear on the batteries, but it seems like a killer application for EVs and rooftop solar to be able to combine them like that.

grogenaut 5y ago

I enjoy how you are taking all of the arguments people used against BEVs in favor of gas and using them against HV. The irony is strong in these threads.

_ph_ 5y ago
Sorry, I don't get what you mean. Which arguments are you referring to and what is ironic?
DeRock 5y ago
BEVs are much more energy efficient than ICE. When was the argument that they are not ever used?

Mvandenbergh 5y ago

The question is not whether you pay a massive efficiency penalty for storing electricity as hydrogen (obviously, yes) but whether there are applications where you are effectively buying a set of useful properties for the losses you are "spending". For displacing existing grey hydrogen from the chemical industry, a possible reducing agent in steel making, and other high temperature industrial processes it's pretty clear that the answer will be yes. I happen to think that it is really unlikely that the answer for cars and vans will ever be yes, even if hydrogen could be made cheaply. Whether it will have a role in other applications depends on a few things: First, the structure of the future electricity mix. In order to ensure that there is enough electricity at every moment, we have to do a mix of things: -"over" build variable output renewables so that the troughs in production are higher -Intra-day demand side response -Intra-day storage (almost certainly batteries) -Dispatchable renewables like hydro -Dispatchable sort-of renewables based on biomass -Dispatchable fossil fuels (with CCS) -Load-following nuclear The reason why people think about hydrogen and other exotic technologies is that many of the technologies on that list either have limited available scope (hydro, biomass), are probably not really carbon-neutral (biomass, CCS), rely on unproven tech at scale (CCS, new nuclear designs), or have exceptionally high capital costs (any new nuclear but especially when at low load factors, CCS especially at low load factors). So what most simulations show you're left with as a low-cost mix for most days is a combination of the first five. That still leaves you with two problems: -What do you do if the average output net of load is very different between seasons? -How do you provision for a 1:20 yr weather system without making your system vastly more expensive? and one opportunity (which is also a challenge): -variable renewables are cheap and getting cheaper so cost-optimal generation mixes build a lot more than needed for the average day in order to keep use of expensive biomass and limited hydro capacity to a minimum. As a result, electricity has low/no marginal value a lot of the time. Second, the future cost of electrolysers. At current capex levels, they need to be run at max load all the time and still produce expensive hydrogen. Genuinely low costs like what BNEF thinks might be possible ($100/kW) allow you to run for only 20% or less of the hours in the year and scoop all the excess electricity up. Third, the cost of alternative solutions in the areas where hydrogen is currently being considered as this reduces the value of any hydrogen produced. I do agree that for passenger cars it's just not going to happen.