What will you use fuel cells for?

[THX1138]

I was wondering what use people might have for fuel cells. Do they produce enough power per unit fuel to enable them to power the drills and ore refiner, perhaps at such a distance from Sol that the solar panels are not viable? I can't think of any other applications where I'd want to trade fuel for electrical charge.

[Anquietas314]

Do they produce enough power per unit fuel to enable them to power the drills and ore refiner

Yes, even if you're foolish enough to sit there mining the launchpad . Note that they scale their power production/fuel consumption depending on demand/supply.

[zarakon]

For probes out to Jool or beyond, before unlocking RTGs

[Geschosskopf]

Apparently you can run 2 ion engines off 1 6-pack fuel cell with a net Isp (including LFO consumption) of about 1600s (in space, rather less in atmosphere). This isn't as good as a solar ion, but is twice as good as an LV-N and far less massive, so has its uses.

The main use I see for fuel cells, however, is mining the moons of Jool. Solar panels are reportedly pretty much useless beyond Dres now, and mining takes a fair amount of power. As do the rover needed to move a very heavy mining rover.