I keep reading about how great the energy density is for hypothetical fuel cells, but as far as I can tell these objects do not exist in any practical form outside of laboratory prototypes and "educational" kits. I keep reading statements like "our company is developing... blah blah". When I do a search on Amazon for fuel cells the only thing that comes up is "kits", books on "how to build your own cells" (LOL), and racing fuel cells (which are just special gas tanks, not hydrogen fuel cells).

So, practical fuel cells actually exist or it is just a bunch of hype and wishful thinking? By "practical" I mean a fuel cell of 500-2000 watts for a home solar system and includes cost as a factor.


After further searching around I did find some practical fuel cells and found out why they are not readily available: because a 500 W cell that would be enough to power, say, a computer, costs \$10,000. For \$10,000 I can buy enough electricity to power the computer for hundreds of years. So, the practicality of these devices appears to be limited to the International Space Station and things like that.

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    $\begingroup$ Do practical fuel cells exist (like you could use in a 500-2000kw solar system)? By "practical" I am including cost as a factor. $\endgroup$ Jul 11, 2016 at 15:19
  • $\begingroup$ Thanks - that at least is enough to make it answerable. I'm not sure how one would use it in a solar system, though, so I'm intrigued by that. $\endgroup$
    – 410 gone
    Jul 11, 2016 at 15:32
  • $\begingroup$ @EnergyNumbers The problem with solar energy systems is that at higher latitudes you get a lot more sun in the summer than in the winter, so you need some way to store the energy from the summer to use in the winter. The fuel cell potentially offers the way to store the energy as hydrogen. $\endgroup$ Jul 11, 2016 at 17:28
  • $\begingroup$ Seasonal storage is going to be expensive, and I wouldn't expect fuel-cells to be a good option. How far is it to the nearest grid? It may be cheaper just to connect to that. Your next-best option is probably a shipping container of lead-acid batteries. $\endgroup$
    – 410 gone
    Jul 11, 2016 at 18:24
  • $\begingroup$ $10,000/500W is madness for domestic users but for some applications it's worth every penny. I've read a few books on spy gadgets and those guys do some mad stuff - burying equipment, for example - where a device like that would be considered very economical. Pacemaker nuclear batteries supposedly came out of spy gadgets. $\endgroup$
    – John U
    Jul 12, 2016 at 10:35

1 Answer 1


Fuel cells have hit the start of commercial success in Japan, where sales so far have been at least 120,000. Given they only became viable commercial products very recently, that's pretty good uptake.

They're generally being used there as domestic CHP systems.

There are still open questions about their long-term reliability.

So yes, they've grown beyond being a product that only existed as prototypes and unique one-off applications.

As to whether they are economically viable - well, that depends on a lot of local factors. Available grants, feed-in tariffs, your retail price of electricity and of any heat supply, the ratio of your electricity demand to your heat demand, the price of carbon, the grid's carbon intensity, the carbon intensity of the fuel cell's fuel supply, and so on.

It's not yet clear where their main markets will be: whether it will be mobile or stationary applications; and for domestic, commercial or industrial usage.

I recommend this peer-reviewed paper "Current status of fuel cell based combined heat and power systems for residential sector" by Ellamla et al from 2015 for a thorough overview of the particular market segment named in the title.

Fuel-cell vehicle sales have only been in the hundreds to date. There may be a market for hydrogen-powered fuel-cell freight vehicles; though they would appear to have comprehensively lost the car / automobile market to battery electric vehicles.


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