You asked about the availability of water and solar energy. Water availibility is actually not the problem. Therefore, finding enough water to perform electrolysis would not be a problem at all.
Solar power is tougher question.
Jupiter is five times further from the sun than the Earth is. So solar energy is rather feeble at Jupiter. This is precisely why Galileo has nuclear power sources on board to provide spacecraft power. I think this is feasible, but not for some years.