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It's too late for hydrogen. For hydrogen to be green is has to either A) be more green than storing the generating power in batteries and using it from there or
by causi 4y ago
It's too late for hydrogen. For hydrogen to be green is has to either A) be more green than storing the generating power in batteries and using it from there or B) be created with something other than electricity. It's too late for A, batteries are already too good. As for B), feel free to come up with some kind of metamaterial that can produce hydrogen mechanically and in doing so bypass the efficiency loss of electrolysis.
- hnlmorg 4y ago> For hydrogen to be green is has to either A) be more green than storing the generating power in batteries I thought batteries had some pretty toxic elements inside them? I don’t know much about using hydrogen as a power source so I’m interested to understand how it’s less green than batteries.
- causi 4y agoCorrect. For hydrogen to be green it has to be more green that producing and using batteries. We're already past that point. Well past it, in fact. The generation-to-tires efficiency of BeVs is 77%. For hydrogen it's 33%. Modern fuel cells have an H2 to electricity efficiency of 55%. You could make that 100% and it would still be less green than using batteries.
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- ncmncm 4y agoRound-trip efficiency is not actually very important when generation has zero marginal cost. You just add more panels. It matters, but other things matter more. Panels are very cheap.
- ncmncm 4y agoThere are lots of different battery chemistries. All are pretty expensive as places to store utility-scale energy. Prices are still falling. Toxicity will not be any sort of long-term problem, although in the short term lithium batteries will explode fairly often (e.g. in Teslas) releasing gas that turns into drain opener when it hits your lungs. In the future we will prefer safer forms, such as solid-state electrolytes.
- hannob 4y agoHow do you make ammonia with a battery? The target use case for hydrogen isn't the cases where you can use a battery. It's all the places where that doesn't work.
- ncmncm 4y agoThe hydrogen or ammonia is the battery.
- amluto 4y agoThere is an electrical use case that hydrogen can solve that batteries cannot (at least not anytime soon): moving energy without relying on transmission infrastructure. On the one hand, this is absurd: transmission lines are all over, are quite efficient, and work today. On the other hand, in some markets (cough California), the incumbent utility prices are rather divorced from actual costs. The ability to make hydrogen, move it on a truck, and turn it into electricity somewhere else, even at 40% overall efficiency, could be much less expensive than selling electricity to PG&E and buying it back elsewhere.
- ncmncm 4y agoBatteries have the serious downsides that (1) they cost more than almost anything else, and (2) cost is per kWh stored, rather than just kW in and per kW out. Flow batteries could mitigate this some where electrolyte is cheap. Synthetic fuels have the enormous advantages that (1) tankage is super-cheap (negligible cost per kWh), (2) tankage is easily transported, (3) there is unlimited market for them, (4) you can burn them in existing combined-cycle turbines. These advantages easly overwhelm low round-trip efficiency, which is anyway relentlessly increasing. We will be shipping hydrogen or ammonia from the tropics to Baltic states in winter. It is hard to imagine any viable green alternative, aside from reliance on fallible transmission lines.
- twobitshifter 4y agoI think maybe for cars it’s over but the energy density argument still favors hydrogen so I’d add another option. C) provide greater energy density allowing for heavy equipment, trucks, trains, and planes to use electric power.
- ncmncm 4y agoLH2 will be unbeatable as aircraft fuel. Once LH2 airframes enter a market, the old stuff will be totally unable to compete. It remains to be seen whether existing airframes can be retrofitted with under-wing LH2 tank nacelles, or if we will need whole new airframes.
- ClumsyPilot 4y agoYou are missing storage capacity - you could install a cheap storage tank and store enough hydrogen to last months. With batteries thats impossible - if you did it fir a house, it would cost 10x more than the house.
- Melatonic 4y agoI can see a future where in 200 years we start using it for space travel Ramjet maybe? Or I forget if that is even hydrogen based at all.