But we urban homesteaders don’t need to be stinky since it’s possible and easy to build an outdoor solar shower. There are two reasons this makes sense, particularly in a place with as warm a climate as LA. First of all, you can direct the water straight into the garden and in so doing irrigate some plants and keep that water from uselessly running down the sewer line. Secondly, placing the shower outdoors makes rigging up a solar heating system somewhat easier and less expensive. Of course, the solar heating part isn’t completely necessary, and it’s possible to run the hot water line out into the garden, especially since you don’t need to worry about the pipes freezing here in sunny LA. One thing to remember–however you rig the shower, make sure to keep the water directed away from your foundation.
Let’s say you’re ready to build your own solar heated shower and you’ve overcome your fear of being nude under the all seeing eye of LA’s police and media helicopters, what we like to call our “ghetto birds”. We’ll start with the most simple solar shower designs and proceeding to the deluxe models.
First off is the camping shower in a bag concept. The principle is simple–you fill a black bag with water, leave it out in the sun, and hang it somewhere for your very brief shower. We’ve not tried one of these things, but we suspect that the result would be less than luxurious, and after all, part of the reason to bathe is the relaxation it offers. But, for the mortifier of the flesh out there, one of these things might just suffice. They are certainly cheap at around $18. If you are really cheap, you can improvise the solar bag shower by filling a car inner tube with water and leaving it out in the sun.
A variation on the bag shower can be constructed out of inexpensive black ABS pipe. Basically you construct a square out of pipe, put water in it and let the sun heat it up for a few hours. Your shower lasts as long as the amount of water contained in the ABS pipe. Plans can be found here. ABS is easy to work with, and this particular design could be scaled up for longer showers. SurviveLA will run some experiments with this design and let you know about the results.
In terms of other do it yourself options several folks have experimented with simply coiling up a length of black garden hose on the roof. A nice example can be found here, and also at the Path to Freedom. The problem with this approach is that when the water is out of the hose, that’s the end of your hot shower.
A more advanced DIY solar shower that resembles commercially available (and expensive) solar water heaters can be made by constructing a glass covered collector box containing a manifold of copper pipes that feed into a used water heater. Hot water contained in the copper pipes in the collector box rises up into the water heater that is kept above the level of the collector. Hot water rises just like hot air and the cold water from the tank sinks back into the collector thus forming a circulation loop–this phenomenon is known as thermosiphoning. Some plumbing skills, are necessary, but it’s relatively easy to learn how to sweat copper pipe. We’ve used a system like this provided by the National Park Service on SurviveLA’s trip to Santa Rosa Island. The nice thing about storing the water in a tank is that you can take a shower well after the sun goes down. Plans for this project can be found on the Mother Earth News website.
Whatever approach you try, the key thing is to keep the costs down and to use as many found materials as possible. The water and gas savings per year are minimal, so in our opinion it does not make sense to buy expensive commercial outdoor showers (like the one made by Hammacher Schlemmer) when you can make something yourself.
An excellent roundup of DIY solar projects including water heating can be found at Build It Solar.