Sea and air transport, as well as remote-location generation, and several industrial processes, rely on or benefit greatly from fuel or hydrocarbon-based inputs.
Forgive me for pointing out the obvious, but we already have an existing supply of hydrocarbon based fuels which are relatively cheap compared to the proposed "quest."
They are destroying the environment on which we depend. They are also finite.
They are finite but the finite total is over five times the amount needed to utterly destroy the environment... so we need to refrain from using up that finite total.