I'm going to suggest solar.
There are a whole bunch of ways to power an electrolytic water-splitting scheme, but they all require some initial electrical source and a load of electrical hardware and the additional (albeit not too serious) inefficiencies of water electrolysis itself.
You can cut out the middleman by photocatalytic water splitting. Then what you have is a load of comparatively dumb photocells immersed in water exposed to sunlight, which then evolve gas that can be separated and handled as you would for any other hydrogen source. The current efficiencies are not particularly high, but there's no reason that they should not increase as time goes on. Even with their lower efficiencies, if the cost is low enough the greater simplicity of the plants might well tip the balance in their favour.
The problem of course is that you need both a good supply of water and a good supply of sunlight. There are big chunks of the world that have both of these things, but there are a lot of population centres far from places with really high and reliable levels of insolation.
Work has also been done on photochemical carbon dioxide reduction. The CO2 source for this might be the atmosphere, or it could be dissolved carbonates in sea water. The end product of the reaction is carbon monoxide. Given hydrogen and carbon monoxide, you have syngas from which you can synthesise a whole range of useful hydrocarbons (such as methanol) which are then much more easily stored, pumped or otherwise transported than hydrogen, solving the whole "how do you get hydrogen to central Canada" problem raised above... it gets there in the same way they get oil, petrol and diesel right now. These hydrocarbons can also be used to run fuel cells directly, meaning that vehicle refuelling operations can continue as they do now, or be used to synthesis more complex chemicals such as resins for glues or plastics.
This also has the happy side effect of consuming atmospheric CO2, if the end-products are not combusted.
Electrolysis will still have its place of course... there are places which have convenient supplies of clean and renewable electricity (such as iceland) which might tip the economic balance against artificial photosynthesis, and there will be places that might be happy to use nuclear power, the economics of which will depend very much on local politics. It may be possible to phase it out as efficiencies and costs of artificial photosynthesis drop over time.
With regards to your follow-up question, you can consider that anywhere capable of running photovoltaic cells right now might reasonably be able to run photosynthetic cells too, albeit at lower yields. The possibility exists to have small-scale distributed hydrogen and hydrocarbon plants suitable for community use. The very far north and south would not be able to take advantage of this, but they are already highly dependent on modern infrastructure for their ongoing survival, so it isn't like they end up more vulnerable by a move to a hydrogen-based fuel economy.