Lots of little issues.... biggest is the law of conservation of energy. Just can't get more out than you put in, otherwise you'd have perpetual motion, which is not possible today due to so many factors. Another is the 'hydrogen push' into the storage canister. There is no pump, so the best you could do is just a few millibars over ambient pressure, which is practically nothing. I can't see a generator running on that for more than a few seconds, especially the one shown. You could use a much smaller generator, costs about $100, just to charge batteries. Using LED lighting, you could have lights and internet/cell that would last a while.
If they were to use solar cells to generate the hydrogen, and adding a hand pump to pressurize the tank, then I could almost see this as feasible.
Or just use solar cells to charge batteries. They'd be better off using water recovery systems to purify the urine back into drinking water.