Solar wind density is very low even at Venus it is only 10 or so H+ ions per cm$^3$ but it is moving at a brisk clip of 400 km/s for the slow wind and 750 or so for the fast wind. So (feel free to check my math here) if one collected all the H+ ions passing thru a 1 cm$^2$ square in a second you would collect 400 000 000 H+ a second. With a 388 km$^2$ set of collectors you would get a mole a second or about a liter a minute.
Build one of the dealy-bobs in venereal orbit. Use the mole a sec of hot H+ is reacted with the copious $CO_2$ available in the neighborhood in some kinda high energy Sabatier reaction
$CO_2 + 4 H_2 → CH_4 + 2 H_2O + energy$
producing about 9ml of water and 11.2 liters of methane a second. That's 778 liters of water a day enough for 259 people (who like to pee off the side of balloons far more with a conservation and recycling effort.) Of course, the collectors could be scaled up.
So here are the issues. 1) What does the collection tech look like? I assume it creates negatively charged fields to funnel the H+ ions into the atmosphere.
2) What amount of energy is needed to run it? Would Photovoltaic be enough at that range? Assuming highly efficient panels. Could the high energies of the particles themselves be used as an energy source?