MemberJune 5, 2022 at 6:43 am
Toyota has been Hydrogen-Only for decades and while they have low production vehicles, they haven’t made any worth going to the mass market, nor does the infrastructure exist to support them unlike gas stations everywhere and houses common enough for people to charge without having to rely on commercial charging stations like apartment dwellers would have to. Besides, wouldn’t it be counterproductive for everyone to be driving around bombs?
MemberJune 5, 2022 at 3:01 pm
All true but similar things were said about the EV before Tesla.
MemberJune 5, 2022 at 6:57 am
Off the top of my head: hydrogen is clean to burn but not clean to produce. With the current Aptera design, there are manufacturing issues with exotic metals mining practices, (eg. cobalt and lithium supply and mining) and the plastic resins used, but actual use after production will be at or near environmental impact zero.
I love the idea of hydrogen if only cracking it out of some source didn’t require large amounts of energy.
MemberJune 5, 2022 at 7:39 am
A very impractical view. There is no Hydrogen infrastructure (Vs. charging) for either manufacturing or distribution for wide use in the US. We would have to wait a long time for sufficient hydrogen infrastructure to be available to make its use practical. Then there is the issue of the availability of cars that use hydrogen…..
MemberJune 5, 2022 at 7:09 am
The only place for clean hydrogen is as a replacement for dirty hydrogen for things like fertilizer. As a transportation fuel it’s a non starter. It’s inherently expensive because the electricity to hydrogen to compression to transportation to fuel cell path is very inefficient, about 2/3rds of the energy is wasted in that chain. The next problem is it’s very poor volumetric density, that effects everything in the chain from the transportation from the generating sites to the car itself. You only have to look at the Toyota Mirai to see the problem. The 10,000PSI tanks take a lot of room and unlike batteries, which can be spread out conveniently, the geometry of the tanks is limited by the requirement that they hold a gas at 10,000PSI. The Tesla Model 3 has more than twice the cargo space as a Mirai, it also has more passenger space. The curb weight of the Mirai is 4,255 to 4,335lbs, about the same as the long range AWD Model 3. The RWD Model 3 is 3,648lbs, the Mirai is RWD so the RWD Model 3 is more comparable. Finally there is the problem of fueling infrastructure. A hydrogen station costs about 10X as much to install as a Supercharger and you need 10 times as many of them because you can’t fuel a hydrogen vehicle at home.
There is a massive market for hydrogen already, the fertilizer market is $190B. Replacing hydrogen derived from natural gas with hydrogen derived from renewable electricity is a tremendous opportunity. It makes no sense to think about using hydrogen as a transportation fuel until the easy markets, i.e. the places where hydrogen is already used, are satisfied.
MemberJune 5, 2022 at 12:30 pm
One point to keep in mind is that HFC vehicles require battery packs, usually about the same capacity as those found in PHEVs. So it’s not an “either/or” situation…
MemberJune 5, 2022 at 3:48 pm
I see a number of problems and opportunities.
I think hydrogen is a good way of storing energy in static applications.
There are two questions that need addressing
1. How do you encourage electrolysis of water as the manufacturing process over breaking down hydrocarbons producing CO2 as a bi-product?
Perhaps the answer is to the CO2 bi-product is to make Urea in stead of CO2. Pipe the CO2 into a secondary process and produce something like Urea for fertiliser.
Perhaps the answer is a Carbon tax where the price is set at the difference between the cost of H2 made by reduction from hydrocarbons and the cost of H2 made by hydrolysis of water.
2. Compression of the H2 up to the required pressures is a waste of energy. You use all that energy stuffing it into a bottle …. only to let it out again.
IF you did the hydrolysis inside the H2 compressed gas bottle and injected the water into the bottle, while releasing the O2 bi-product from the bottle, then you could have compressed hydrogen without compressing it. Let the hydrolysis do the compression for you as it is not inhibited by the gas pressure (irreversible reaction). (Chemistry nerds PLEASE correct me where I am wrong ….. economics nerds I assume I am wrong.)
I hate it when people write stuff like I did above, please shoot me.🤓
MemberJune 6, 2022 at 6:13 pm
Thought it might be worth re-posting this here:
MemberJune 6, 2022 at 8:52 pm
Hydrogen would be a very poor substitute for our existing use of oil products. This is especially true when you take note of the fact that the majority of commercial hydrogen would come from the cracking of oil products to begin with. You can’t mine hydrogen. It has to come from something else. I suppose it would be possible to split water, but that would take electricity. If you have electricity to start with, why use it to create another product that has marginal storage possibilities, and then burn it with oxygen in an ICE with its inherent poor efficiencies. Not to mention the difficulties of storing hydrogen and moving it around from one vessel to another. It tends to leak.
Along with all the other points made before my post, here’s one more thing to consider. Hydrogen in the troposphere reacts with hydroxyl molecules to form water vapor. Not too bad by itself, but hydroxyl molecules tend to mop up methane in the atmosphere. With a hydrogen infrastructure and all the inherent leaks, those hydroxyls would not be available to remove the methane which would indirectly make hydrogen a greenhouse gas.
MemberJune 6, 2022 at 9:02 pm
Hydrogen (or compounds of it like “powerpaste”) are the only viable mid term approach for applications that need very high energy density like commercial aviation. We would need 1500 wh/kg batteries for any potential of intercontinental aviation (far more to match current ranges)
MemberJune 6, 2022 at 9:22 pm
There is a book by George Monbiot called “Heat, How to Stop the Planet from Burning” in which he has carefully laid out the way we might be able to avoid heating our planet beyond two degrees Celsius. It’s a bit dated now, but he determined the amount of CO2 each person could produce each year in order to stabilize at our current temperatures. In it he was able to find alternatives for everything except aviation to avoid going over that limit. Just one plane flight from NY to London with a full passenger load would use the entire year’s allotment of CO2 for those passengers. It would be nice if he was wrong. Maybe someone will find a pollution free way to do it, but I’m not too hopeful. That means we either stop flying completely, or we continue to go up in temperature.
MemberJune 7, 2022 at 5:49 am
Electricity is difficult to store on a grid scale.
Look up catalytic reforming of methane to produce hydrogen. Note the first step in the reaction is endothermic. Use methane and Solar / Wind power to make CO2 and H2. In stead of wasting the electricity that we can’t store and burning Methane … Add energy, produce less CO2 and burn hydrogen in stead.
Ideally they would produce hydrogen from sea water ….. With care, it can be done without producing nasty chlorine biproducts ….I do not know if it is economical.
There is no perfect solution to global warming. If there was then we would not have a problem.
We have to use our smarts to make best use of imperfect solutions depending on the problem to be solved and the available resources.
MemberJune 7, 2022 at 9:49 am
Their are a lot of potential ways to store grid energy. Lithium-ion is really only good for short term balancing since it is very expensive and competes for resources. Without storage good enough for seasonal usage it will be very difficult to ever use renewables 100% in places with actual seasons.
The key challenge with hydrogen for grid is that storing it is tricky (leaks super easily) and it damages metals over time. This makes massive farms of hydrogen tanks storing days of power for seasonal very questionable.
Here are a few that I think have a lot of potential:
Liquid Metal Batteries / Flow Batteries / Aluminum Air / Sodium (1 day cycle)
Thermal Storage potentially with Thermal Photovoltaic (https://www.youtube.com/watch?v=Gn7pfYKB7DA)
Gravity/Buoyancy Storage (ie Gravitricity)
Another option is to create an energy economy that can make use of intermittent power then simply overproduce renewables and use the extra cheap power for these special cases when available. Desalination/Lithium extraction from sea water is an option. On a day cycle this could be maintaining temperatures for smelting. We could also use this to run active air capture using government funding to clean the air (especially near cities).
MemberJune 7, 2022 at 3:07 pm
If I was investing in a battery company for grid storage I would invest in this.
Infinite cycles, ok with complete discharge, cheap materials that are available the world over, no risk of thermal run away.
DC efficiency better than 80% under almost all circumstances.
Calcium Antimony molten battery.
- This reply was modified 3 weeks, 5 days ago by Llewellyn Evans.