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Cheap, green hydrogen would be a breakthrough in clean energy

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Re: Cheap, green hydrogen would be a breakthrough in clean energy

#61

Post by freemint »

partiallypro wrote: post #17
freemint wrote: post #10

Yeah, so would cheap nuclear power or cheap batteries. I find cheap batteries way more likely then either of those.

I think the current problem with batteries is that it presents a geopolitical risk that is akin to (maybe worse than) oil.

Unlike oil once there are enough batteries in a country that country is good for a long time as a batteries can be recycled quiet well (lead acid batteries have a recycling rate of 99.99x%, it is just a question of political will and new batteries being cheap right now).

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#62

Post by ZeroGravitas »

derriz wrote: post #25

I don't see hydrogen playing any role for energy storage or grid demand balancing. Even if all the technical and engineering challenges associated with storing and transporting it safely could be addressed, I just don't see how the economics of green hydrogen is supposed to work. The round-trip energy efficiency of electrolysis-fuel cell is poor - currently about 40%. The counter-argument is that such inefficiency do…

The gray stuff isn't cheaper, the cost is just passed onto someone who can't directly input into the decision to use it or an alternative. If they could, the problem solves itself because it's obviously more expensive to be dumping stuff and then extracting it again rather than just not dumping it in the first place.

Four decades of climate change discussion and the single most important economic lesson to be taken from it, one that is absolutely basic free market economics, is still successfully suppressed and widely misunderstood, even in technical forums like this, full of people who think of themselves as libertarians. It's an impressively evil achievement for the fossil fuel producers.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#63

Post by leobg »

rich_sasha wrote: post #59
derriz wrote: post #25

I don't see hydrogen playing any role for energy storage or grid demand balancing. Even if all the technical and engineering challenges associated with storing and transporting it safely could be addressed, I just don't see how the economics of green hydrogen is supposed to work. The round-trip energy efficiency of electrolysis-fuel cell is poor - currently about 40%. The counter-argument is that such inefficiency do…

The point is that some countries have long dark winters, often with windless spells. Some are also lowland countries with little or no access to hydro. For green energy, you'd need to literally store months' worth of energy somehow, and the cost of doing that via batteries is prohibitive too. I guess the hope is that storing hydrogen, difficult and expensive that it is, could be made to be more like storing hydrocarb…

Exactly. The solar energy that can be captured throughout the year using not much more than the roof area of a single-family home would be enough to cover its entire annual energy needs, both for electricity and heating. The problem is that you need to store about 30,000 kWh of energy over a period of several months. That’s on the order of 400 Tesla Model 3 batteries worth of storage. Not only is it prohibitively expensive. Those batteries would also be missing in production of electric vehicles.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#65

Post by timerol »

jxramos wrote: post #28

Is that metal hydride stuff feasible? I heard about it and saw videos around the claims of the substance but was curious why it never took off if it was so great. What are the challenges around it precisely? https://www.energy.gov/eere/fuelcells/metal-hydride-storage-...

Metal hydrides are a great way to store hydrogen that bypasses the alternatives of very highly compressed hydrogen or liquid hydrogen. However, storage is only part of the equation here.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#66

Post by cagenut »

oh_sigh wrote: post #51
cagenut wrote: post #12

Earlier quoted context omitted.

All of the synthetic light hydrocarbons (e-fuels) involve extra energy on top of the hydrogen production. Its pretty much right there in the name (hydro carbon). So for instance, we could make a ton of hydrogen and then burn it for energy, or we could make a ton of hydrogen, add in a few hundred kilos of carbon and more energy to produce e-fuels that we then burn for energy. For logistics reasons it will almost certa…

Right, but the problem is really with hydrogen handling, and all the complexities that would be pushed onto, say, every vehicle. Keeping a hydrocarbon in a container is much, much easier than keeping a single hydrogen atom in a container.

once again we are not talking about cars

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#67

Post by taneq »

The question isn't whether cheap, green hydrogen would be great to have. It's whether there is any physically possible world in which cheap, green hydrogen is better than cheap, green electricity in general.

The problems with hydrogen aren't just absolute, they're relative.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#68

Post by amluto »

causi wrote: post #18

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 elect…

There 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.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#69

Post by ncmncm »

Barraketh wrote: post #52

Ammonia has been mentioned a few times in this thread, but I will expand a bit, because I believe it is the most promising hydrogen-based approach. Essentially, the idea is to use ammonia directly as fuel. There is an ARPA-E funded project (that I'm currently failing to find) that cracks ammonia into hydrogen and nitrogen using heat. They claim that they can create a mixture of H2 and ammonia that will burn at any re…

Diverting money from building out renewables to building nukes, for whatever purpose, brings climate catastrophe nearer.

If ever there was a process forgiving of intermittently available energy, it is chemical synthesis. The same money spent on wind and solar would produce a lot more ammonia.

Conversion losses don't matter much when marginal cost of generation is near zero, as we get with renewables, but very much not, with nukes. You just build out more panels.

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