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Yes, the cost structure is very visibly more expensive. The problem is the huge amount of additional energy needed to generate the hydrogen. Hydrogen storage is
by _ph_ 6y ago
Yes, the cost structure is very visibly more expensive. The problem is the huge amount of additional energy needed to generate the hydrogen. Hydrogen storage is also very expensive. The weight reduction is pretty neglectible, as hydrogen is the lightest element in the universe.
- kube-system 6y agoFor anyone wondering what kind of numbers we're talking about in practice -- the Toyota Mirai holds about 5kg of Hydrogen.
- bryanlarsen 6y agoIn a pair of tanks that weigh 87.5 kg.
- wmf 6y agoThat ratio looks depressing, but what would equivalent batteries weigh? 500 kg? 1,000 kg?
- bryanlarsen 6y agoA Tesla battery pack of comparable range is about 500kg.
- bodhiandpysics1 6y agoNote that the mirai also needs the fuel cells, which adds another 70 kg, so the difference isn't as stark
- bryanlarsen 6y agoOnce we start that game, we can also add the weight of the Mirai's 1.6kWh NiMH battery and other esoterica. The proof is in the pudding: the curb weight of a Mirai is more than that of the larger and more capable Model 3.
- 8note 6y agoHow important is weight in their designs though? They're cars, so they don't have to hold themselves up, and they probably both have regenerative braking
- _ph_ 6y agoYou are right, weight isn't extremely important, especially with regenerative braking. It is only interesting in the comparison with battery electric cars - if the hydrogen car is even heavier, then there is basically no advantage left for the hydrogen car.
- dnhz 6y agoThat's not that bad right? 15 gallons of gas could be 43 kg, and the gasoline fuel tank has some weight too. Although, after google search, I see that the Mirai weight is 4075 lb, and the Prius weighs around 3100 lb.
- wombatmobile 6y agoWhat is the energy came free, from renewables? What would the cost structure for hydrogen be in that case?
- cmrdporcupine 6y agoYou'd still have to compare it to the equivalent usage of the same energy into a LiOn battery, and in many cases it wouldn't fare well. Maybe there's a future world in which we can do it all in orbit -- harvest comets, produce hydrogen in space using solar power or nuclear, and efficiently drop it down to earth in some safe way. That would definitely alter the equation. But by the time we figure that out, it'll probably be too late.
- nsonha 6y agoIf we're talking about space mining is Lithium abundant too? It's number 3 so should be everywhere in the universe?
- _ph_ 6y agoThere is no free energy from renewables. Renewables are cheap, but not free. And we are very far from even having a 100% renewable grid.
- VBprogrammer 6y agoWhen the spot price for energy can go negative due to renewable over production it's fair to say that energy can be free or even better.
- _ph_ 6y agoYes, in those rather short time periods, energy prices are free. But for those periods, batteries are the better storage solution, as the total amount of "free" energy is rather small. Electrolysis plants would have to run basically 24/7 to be viable. More battery electric cars on the roads also mean a lot of storage for excess electricity. Just use the top 10 to 20 percent of the capacity to absorb production peaks.