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.