MIT design would harness 40% of the sun's heat to produce clean hydrogen fuel | Hacker News Reader

MIT design would harness 40% of the sun's heat to produce clean hydrogen fuel

news.mit.edu

45 pointsBrajeshwar8 comments

Headline theatrics aside, this seems like a neat idea. However, the article doesn’t mention how this compares to systems that use electrolysis to generate hydrogen. In general the number of mechanical moving parts required for this system, and the idea of rusting and de-rusting these metals over and over doesn’t seem feasible compared to simply using electricity to separate the hydrogen. A quick google says electrolysis is around 70-80% efficient, I don’t see this setup ever beating that.

But solar has <50% efficiency so you're looking at less efficiency overall. But yeah seems finicky. And won't you need to also spend a bunch of extra energy desalinating/distilling for either option?

40% of the sun's heat? Damn, those MIT engineers are good.

I guess they wanted to leave some for Harvard, Stanford, and Caltech engineers too.

I think that is another way of saying it’s only 40% efficient

This article strongly asserts that Hydrogen is the fuel of the future.

There is no evidence towards that yet.

I think hydrogen will definitely be a “feedstock of the future”. It’ll be critical for green production of many materials and fuels.

But there’s no reason to use hydrogen if you can produce and use other green fuels with good efficiency. Hydrogen is hard to handle, leaks easily and has bad volumetric energy density.

But it’ll take time to develop methods of production and fuel cells for fuels like methanol, that are efficient enough that it’s worth the extra cost over just using hydrogen. So in the near time there’ll probably be some niches for hydrogen.

But in the long term, considering that hydrogen is completely unviable for large scale long distance shipping (the shipping industry is looking at ammonia for that) and long haul flights, and that hydrogen is unviable for ground transportation in the long term (batteries will clearly win there), I think economies of scale will push out hydrogen fuel in favour of whatever the shipping and airplane industry ends up using.

The people currently building out to expand the global green hydrogen production fourfold are already planning, with advance contracts on the table, on shipping 'hydrogen' as ammonia.

Unprocessed hydrogen doesn't have to be shipped to be useful, global hard rock mining currently consumes about 10% of global energy - a 24/7/365 mining operation can use solar farms for direct power and hydrogen production during sunlight and convert hydrogen to electricity off peak - all within the mine footprint planning which has already in modern times had to include a small city | large town power station.

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