Thanks for the welcome. You propose some interesting thoughts. Here's an article that details the costs of producing 20% of our electric power from solar photovoltaics.
The cost with the voltaics and maintainance accounted for is cheaper than we currently produce electricity, but not much
$0.074/ kWh vs. $0.10/ kWh. That was assuming 90% savings from present costs due to economies of scale.
I think solar has great potential to replace fossil fuel generated electricity, but I would guess the cost of turning that electricity into hydrogen and distributing it to be a big extra. Gasoline is about 4.5 cents kWh at $1.60 a gallon I think.