I recently obtained a 45 watt solar panel, and have been thinking of setting up a hydrogen production experiment. I wonder if anyone has any experience with this that might be helpful? For example, it occurs to me that electrolysis in a closed chamber would have to produce an increase in pressure, and that this pressure must eventually slow the production of gasses. Where can I find the relevant formula? How can I calculate the equilibrium point? Thanks for any thoughts. I am aware that hydrogen is an explosive gas and that I need to take precautions. This is only a thought experiment so far, and the volume of my little set up is bound to be very small, so don't be overly concerned about my welfare.