Thank you for commenting! Generally I would agree, that artifical chemicals could replace fossil fuels in every application. They can most probably be made using renewable inputs (intermittency of energy supply does somewhat reduce the efficiency of such processes, but that's not my greatest concern). My problem with this approach is, that we are loosing a lot (30-50%) of our hard earned renewably produced energy in every step of this process. Thus the energy invested in establishing the required infrastructure (panels, processing facilities, water treatment and pumping for H2, etc) would propably never produce a payback. Thus we would quickly find ourself in a situation where we are building these facilities just for their own sake, not even capable to produce the energy needed for their build out in the first place. Fossil fuels on the other hand come with all these processes pre-done for us... And today, when we still rely on them, we already face a problem of diminishing returns on their production (what economists call lack of investment).