Water is critical but not hard to get.

Right. https://en.wikipedia.org/wiki/Water_scarcity

You would want to use solar power for electrolysis. In the US, regions with abundant solar power are also the ones that: - have true water scarcity - Nevada and Arizona - have low population and industrial density, so any generated hydrogen would need transported to the point of use.

The bigger problem is the energy disparity. Electrolysis of water requires 50 kWh/kgH2 or more. Even a 70% efficient fuel cell would get ~25 kWh/kgH2 -- horrible roundtrip efficiency. With pyrolysis, that equation is exactly inverted: at 9-12 kWh/kgH2, you can generate excess electricity with no CO2 emissions.

Plus for pyrolysis, you have to deal with the carbon which makes up 75% of the methane by weight. A non-trivial issue.

Exactly. 20 kg of methane costs $3 today, but contains 15 kg of carbon that could be worth $20-$30. It's a non-trivial issue if you hate generating value.

https://www.chemanalyst.com/Pricing-data/carbon-black-42

> In the US, regions

First of all the US isn’t the whole world.

Like you said transportation is a problem which is why you would produce it close to where it’s needed (say Nebraska). You don’t need an “ideal” solar output location.

Yes I am well aware of the energy difference.

> Exactly. 20 kg of methane costs $3 today, but contains 15 kg of carbon that could be worth $20-$30. It's a non-trivial issue if you hate generating value

If carbon free hydrogen is going to be worth doing at scale it will be because there is a price on the carbon. So the input methane will go up in price.

As for the output, global demand for carbon black is currently ~14 million metric tones a year [0].

Current hydrogen demand is ~100 million metric tones a year [1].

100 Mt of hydrogen needs ~400 Mt of methane and produces ~300 Mt of carbon.

300 Mt vs 14 Mt of current demand. What do you supposed will happen to that carbon black price when you produce even a fraction of total hydrogen demand through pyrolysis?

It’s non-trivial cause you’re gonna be having to create reverse coal mines to store all that shit.

[0]: https://www.chemanalyst.com/industry-report/carbon-black-mar...

[1]: https://www.iea.org/reports/global-hydrogen-review-2025/dema...

A lot of those countries with water scarcity are oil rich. A lot of those countries that don't have water scarcity are oil poor.

Seems one forward step would be for countries that have an abundant source of alternative fuel to go for it and stop importing so much oil. Countries that don't have much water can import alternative energy sources or keep using the oil that they're rich in.