Portable Solar Water Filter

I think the ceramic filter, hand pump camping models, will be a lot less hassle.

How much daily water do you need?

40' of elevation would give you 20psi, so you could hang a water bag, pump up to it, and then let it filter overnight, ready to go the next day.
Also, there is now, some thought to UV pasturastion, where you have a clear water bottle, lay in sun all day, and the suns UV cleans it up.

Mike,
Thanks for the suggestion but its kind of hard to get a 40' elevation drop and produce mass amounts of water. We'd have to bucket up the canyon walls that at certain locations will be sheer. Plus no UV pasteurization. The high capacity pump filters are not exactly cheap either, ($1,200) and don't have UV pasteurization that requires you to put sanitizing tablets, iodine or bleach in the water. None of these options taste good.

The first main use of this setup will be for a seven day Middle Fork of the Salmon trip. The trip is in August and we have to go light for the first 25 miles because of low water. At ~8lbs/gal we don't want to have to bring our own water in with us (~840lbs for 7 days). We will need around 15gal/day (15people @ 1gal/day). Once we are past the 25 mile 'light rafts' section we might want more in the boats to add weight (momentum) to punch through rapids. On the Middle Fork we are not so concerned about the UV pasteurization but for a Grand Canyon (16 days next Aug) its almost a requirement. The sewage plant in/near Page sometimes overflows into the river leaving nasties.

To me this seems like a simple 'get to know solar' project. For the overnight river trips it would be nice to be able to recharge camera batteries, maybe have some music at camp, LED camp lights, etc. For all these uses we would be mainly charging the (solar unit) batteries during the day and then discharging them at night.

So can someone help me with picking an ample solar panel to charge a battery? Is there a something like 25w panel will charge a 8Ah battery in _________ hours?

Get a hand pump expedition water filter
or the hang bag type: http://www.rei.com/product/737349

forget electric

Lets say you get 3 hours light in canyon & battery is totally flat. You need 120% of amps to recharge it. (9.6A) and only 3 hours to do it in. So you need a panel that produces 3.2A @ 18V (57W) Panels lose power when outside the lab, so you need an extra 20% in the panel to compensate for that loss. That brings you up to a 70W panel, for 3 hours of sun, to charge the battery.
And you will need a charge controller for it too.

You talk about going light but how much would this solar powered water filter weigh compared to a hand pump water filter? I would think a hand pump could create that much psi and be modified to work with a refrigerator water filter. I would test the water with a hand pump and the solar powered pump and see if there is really a difference in the quality of the water? It might be a waste to carry a solar powered water filter set-up.

Trying to produce electricity while floating down the river. Not a good idea. Get a Bergey or build a Bergey clone out of 2 - 5gallon butckets.

WWW

this will produce much more water per day at about 1/3 the weight and risk of toting PV down a river and at less than 1/10th the cost.