Japanese idea of using satellite for split water on the ground

In response to the material below, another perspective: Methane (CH4) is
also a green house gas, and a natural product of biological and geochemical
processes. A lot of methane is released and burned (flared) in oil fields,
which puts the carbon dioxide from that into the atmosphere with no direct
industrial benefit. If that methane were turned into a fuel (such as
hydrogen) that could be economically shipped and marketed, and thereby
replace some other fuel that was to be burned, then that would be a benefit
even if it did make carbon dioxide. Obviously capital and infrastructure
are required for that. But something has to be done with the methane that
is released in oil fields. Methane Hydrate is another problem, although
there are apparently biological sinks for it, though I don't know what the
effluent gases are, in any.
Sincerely, Jay Huebner

Electrolysis IMHO is the best way to produce hydrogen.

The other main competitor is steam reformation of methane which has two
problems:

1) it needs methane - which cost money to purchase, is a finite resource,
and is expensive/dangerous to store and transport.

2) it produces CO2 which is what we are trying to avoid.

Number 2 is the bigger problem, and defeats the object of going to the
hydrogen economy, which is to eliminate CO2 emiissions.

It looks better and better for SPS, unless we go nuclear.