So really, really cheap electricity with a side of really, really cheap hardware[0] coupled with an absence of operations, maintenance, storage, or transport costs. Noting for the latter direct energy from panels must be used with a high locality to the panels themselves, which means a distributed collection and transportation for the produced hydrogen.
[0]Plausibly viable, non precious metal catalysts typically have less than stellar lifetimes but there is a lot of fat to plausibly trim out of an electrolyzed.
[0]Plausibly viable, non precious metal catalysts typically have less than stellar lifetimes but there is a lot of fat to plausibly trim out of an electrolyzed.