We will probably need a little more information from you to really be of assistance. But let me try adding this for now.
A UPS is an "Uninterruptable Power Supply" and is used as an AC backup to protect systems from AC power line fluctuations or even AC power losses. There are a few different types of UPS systems and they are really geared to different types of applications ranging from small (like a personal computer) to large (such as an entire building.)
I'm not sure what you are referring to though in regards to EPS. Did you mean an "External Power Supply" like you would have with a laptop computer? Or did you mean something else?
Please let me know and I'll be glad to help however I can.
The UPS is more viable in any design right now. I purchased a couple DIN rail mount UPSs from a vender B&B electronics... 24VAC; love them. I doubt fuel cell technology is really an option for a viable product right now? I am not saying we won't be looking at this in 5 or 6 years down the road ... Regardless a fuel cell is more like a battery than needs to be replentished were a UPS is a device that just provides stable (hopefully clean) power. I think the best efffiency you can get out of a fuel cell right now is 50% and it drops as current goes up... You'll see much much better with a UPS.
I'm not familiar with an "Electro Power Supply." If it is a fuel cell based device than I would assume it's nothing more than some sort of fuel cell battery like device. Perhaps with an inverter built in to provide an AC output to work similar to a UPS. Not sure there.
I would agree with the other reply that fuel cell technology is still very early in development and if this is for a current project that will move to production a true UPS (or straight battery backup) system would likely be much better for your needs.
Please feel free to contact us at xppower.com if you are interested in talking to us and seeing whether we can help you out further.
