solar hot water- how much can I heat?

I am working on a plan for a setup that will heat water for washing wool fleeces. I am thinking quite low tech solar. No wiring needed would be best, but I could manage something that hooks up to a car battery that I recharge.

When washing fleeces I use plenty of water in a fairly short amount of time. I am not sure what methods would be best to keep around 100 gallons of water hot. By hot I mean between 110-130*F.

I am also working on a plan for the water to go out through a filtering system and the grey water reed bed sort of deal.

Depending on your location this can vary. Here in missouri you would be surprised at what a simple black tank full of water in the sun will be. The water will be too hot to shower with.

How much can you time your cleaning to the heat of the water? If you had two old 50 gallon water heater tanks painted black they could probably build to that temperature on a sunny spring/summer day. But you may have to time your water use to when they are at the right temperature (3:45 PM).

Does the water need to be under pressure? If so you'd have to hook your tanks up to a garden hose and faucet to provide the pressure. Or have them 50 feet in the air to get gravity to provide the pressure.

If you have house water nearby you could plumb the hot water from the tank and the cold water from the house into a mixing valve (like on your shower). Then if the hot water is hotter than you need you can adjust the temp down to what you need (and save hot water).

These solar water heaters are hugely popular in Ladakh over the past few years. I think they're made in China, and the tubes are typical Chinese thermos technology. They don't have an electrical hookup. You can connect them to plumbing, but most people prop a funnel in the top of the inlet valve and fill them by pouring a bucket in. The water gets piping hot, sometimes scalding hot on a sunny day if you don't use it. The tank and the tubes are so well insulated that they don't freeze and clog or break even on winter nights when it goes down to -25C (-13F) with clear skies.

This picture is the one at our school. We also have a lower-tech solar water heater that we designed ourselves, but this one certainly gets much hotter.

Pretty sure http://www.solarjacksonville.org/cost answered your question in that article

thanks for the responses.

if I end up doing things according to my current thinking I would be mainly, if not always, using the water one day per week and do a large amount of washing that day. so something that might take a couple days to heat up might work for me.

the water does not need to be pressurized. my current thinking would be to have the water up on a structure or something and just needs to be higher than my sink.

I wasn't sure about the cold water yet. I am kind of thinking that I could just have a plain old white water tank also on a structure to be higher than the sink.

depending on how things work out with placement of some other things I may have water being piped down the hill for the animals from a small spring development. I could most likely pipe some water to the building this washing etc will be in.