Fuel cell technology appears to have made some progress in the last year. For those who do not know what a fuel cell is it is a generator of electricity that runs on hydrogen. You supply it with hydrogen and it creates electricity and water is the output. Its a green technology. So why have we not all got one? There are a few reasons. The first is cost. Wow, they are expensive. But they are coming down in price. When I looked at them a year ago they were around £25K. There is now one online that produces 3K Watts of power for just under £8K.
The price reductions are parallel to flat screen TVs. As production ramps up the cost will fall. I suspect within a few years they will be £2000 - £3000 (guess). They will be immensely useful things. The purchase price is only half the story though. The second issue is the cost of the fuel. They can use methanol, natural gas or hydrogen. But hydrogen needs to be 99.999% pure which makes it expensive.
Current estimates show that it is cheaper to run a hydrogen power engine with generator than a fuel cell. But that will change soon.
With 3K Watt fuels cells now available (one will run from LPG next year) you can see that at 240V you could get a useful 12 amps per unit. This is a useful addition to the shore power of 16 amps. At the moment they would not power systems directly as voltage fluctuates a lot. But they can be used to charge batteries which would produce more consistent power. The other option would be to feed a Victron Quattro system which would then stabilise the power and if too much power was being drawn it would take from batteries.
There is a solution in there somewhere. Probably something usable by late next year. It does then suggest that any design of the electrical system of the ship should enable this to be done.