General > General Technical Chat
“Battery EV” vs “Hydrogen Fuel cell EV”
nctnico:
--- Quote from: tom66 on March 31, 2022, 07:42:35 am ---
--- Quote from: nctnico on March 31, 2022, 12:46:01 am ---When you have hydrogen on-site it makes no sense to have a big grid connection. Convert it to electricity on-site.
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Convert hydrogen into electricity on-site - at an efficiency of 60% and with all associated costs of doing so - instead of using a grid connection directly?
Why? Hydrogen as storage might make some degree of sense (e.g. large grid-scale storage of excess renewables), but grid connections are far cheaper, let someone else worry about doing the conversion.
Cost per km, hydrogen will always be more expensive than electricity if hydrogen is produced from electricity.
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No. If you look at electricity prices and public charging costs it is easy to see that the charging infrastructure costs make up for the majority of the costs. At a fast charger I need to pay about 80 eurocents per kWh. That kWh costs 6 cents or so to buy in bulk.
Looking at the plans that are in motion and what is being planned where it comes to hydrogen production by countries that have large deserts, it is too soon to claim anything. Keep in mind that a solar panel in a desert in North Africa or North Australia gets more than twice the amount of energy from the sun compared to a panel located somewhere in the UK or the NL. So theoretically a kWh from a solar panel in the desert costs half.
james_s:
--- Quote from: Miyuki on March 31, 2022, 07:49:14 am ---Also, it is "easy" to have months worth of energy in hydrogen
Batteries are good for small scale (phones, tools cars) or quick cycles, like day/night cycle
But for long-term storage, like weeks or months. Other methods like hydrogen or maybe flow batteries to some scale are needed.
There is no way to have a battery for 2 months worth of energy next to a house.
Also, there is no way for a truck or ship to have a battery when you want to replace high-efficiency ICE which is commonly over 40% and can reach over 50% efficiency for long hauls
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Why would you ever need to store 2 months of energy next to a house? Talk about an edge case! For emergency energy it's hard to beat liquid fuel, diesel can be stored on site for years and easily converted into electricity.
Ships? I don't think anything is going to replace oil for a very long time, and when you look at the whole cycle from producing hydrogen to turning it back into electricity the efficiency is abysmal.
Hydrogen is dead, dead dead. It was a stopgap that had a handful of people excited decades ago.
PlainName:
--- Quote ---Ships? I don't think anything is going to replace oil for a very long time
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Ships run on really dirty stuff though, don't they? They could improve massively and still use oil, albeit not the dead cheap almost unprocessed sort.
There have been some interesting wind-powered ships (or, at least, wind assisted). Again, not going to replace oil but it would cut down on its use, which is better than nowt.
Marco:
--- Quote from: james_s on April 03, 2022, 12:19:36 am ---Ships? I don't think anything is going to replace oil for a very long time
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Given the choice ... but lets say we arrive at a point where there's a trillion dollar liquid hydrogen market and some regulators interested in drumming up extra business for it, there's always a chance the choice will be taken away. Or maybe courts in some countries hold governments to environmental promises come hell or high water ... like is happening in my country with NOx emissions (the NOx emission limits are economically crippling, but the courts are holding the government to their promises).
Necessity is the mother of invention.
james_s:
--- Quote from: Marco on April 03, 2022, 01:12:10 am ---Given the choice ... but lets say we arrive at a point where there's a trillion dollar liquid hydrogen market and some regulators interested in drumming up extra business for it, there's always a chance the choice will be taken away. Or maybe courts in some countries hold governments to environmental promises come hell or high water ... like is happening in my country with NOx emissions (the NOx emission limits are economically crippling, but the courts are holding the government to their promises).
Necessity is the mother of invention.
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But there never will be. Hydrogen isn't a fuel, you can't mine it, you have to produce it either by cracking hydrocarbons or electrolysis of water and neither process is efficient. The only way hydrogen even begins to make sense is if you have a massive surplus of cheap electricity.
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