I think fuel
cells are going to be very important to us soon.
What the current cells seem to have against them is that the units are not easily serviced, require very pure fuel
(from the manufacturer, no less), and the initial price is very expensive. All of these barriers are going to go away as the technology becomes more widely available and more manufacturers start making these things, and more people start using them.
I don't think it will be either/or, however, because I don't think fuel
cells are going to replace anything on cruising boats, what I think is going to happen is that the fuel
cell will fit into a niche between (a) wind and solar and (b) generators and shore power.
Today we use free power from wind/solar to charge our banks, but of course that only works when it is sunny or the wind is blowing. When it is dark for extended times without wind, cruisers all try to keep their systems going by conserving power and by using large battery banks, but those dark dull days become a problem after a while. I think that fuel cells are going to settle into this niche where they activate and burn (burn ? convert ? osmose ? what verb do fuel cell people use ?) fuel to make electricity when the battery bank voltage drops down enough for them to supplement solar/wind power, it'll be just like turning on the generator except it'll be much more fuel efficient with less danger (no carbon monoxide). I still believe that many of us will continue to use small generators for heavier loads and for power away from the boat, and we will still use alternators
when the engine is running, and shore power at dock because it will cost less to charge than the fuel/maintenance of the fuel cell when they are available.
I look forward to the day that is probably fast approaching when fuel cells use widely available fuels such as more dilute methanol or ethanol, or diesel, and have parts that can be more easily serviced by end users instead of having to send the units back to the manufacturer to fix them.
Some day I think the day sailors and weekend cruisers will probably rely exclusively on fuel cells so that they don't have to clutter up their deck with solar panels, etc, at the expense of cruising range. The long distance cruisers will still have their solar and wind, supplemented by fuel cells, generators, and shore power, and the wind generators and solar panels will become yet another symbol of the long distance cruising lifestyle along with bicycles, fuel cans on deck, and the rest of the stuff that marina queen owners bitch and moan about when cruisers drop anchor
near them, and yet another thing for us all to argue about on Sailnet.
For people who already have all the luxuries on their boats I think this is an interesting thing to try already, but cruisers who need to economize might want to wait for the early adopters to work all the kinks out of the systems, much as they did for water makers when they first appeared.