What is a solar water distiller?
A solar distiller is basically a simple, waterproof, oblong “box” with a piece of glass on top that the sun shines through, which utilizes the sun’s energy to distill the water. The distilled water is then rendered safe for drinking and cooking, with absolutely no contaminants that are found in regular (potable) water.
How does it work?
Solar stills are JUST LIKE MAKING RAIN. In nature, the sun (solar energy) shines and heats the water in lakes, rivers, and the ocean, and causes the water to evaporate into the air as water vapor. Then it cools down and condenses in the sky as clouds and it finally falls as rain. You can catch this water in a container to use for plants or other purposes.
Similarly, a solar still, also called a distiller, makes ultra-pure water the same way rain is made. The sun’s energy shines and heats the water inside the still causing the water to evaporate and condense on the cooler glass above (the glass acts like a cloud). The water then drains down into a water catching trough and out to a glass jug/container.
This works passively, with no moving parts. You just need the still, a source of water (even raw sewage is okay), and the sun! The output will be pure H2O!
How good is the water?
The water that is made in these stills is a better quality than store-bought purified water because it is ultra-pure. It is some of the cleanest, most pure water you can get on the planet. And because the water is slowly evaporated, instead of rapidly boiled, the water picks up a lot of oxygen and carbon dioxide from the air which makes it taste sweeter by raising the pH to above neutral. Contaminants such as salts, heavy metals, bacteria (e.g. coliform), micro-organisms (e.g. E-coli, giardia, chryptosporidium), sediments, sand, rust, chlorine, fluoride, arsenic, etc. are all completely removed (the are left behind in the basin and/or killed.
What kind of applications are these stills good for?
For the homeowner, RVers/campers, people in rural areas, solar enthusiasts, and more. Grant projects, such as those implemented by the El Paso Solar Energy Association (EPSEA) helped to install over 100 stills in west Texas and southern New Mexico, and Mexico, in rural border colonias (poor neighborhoods) that are challenged with water problems.
The stills are appropriate technology for these areas because they are site-specific, use no electricity to run, have a quick payback period, require no running water to work, get rid of all contaminants including E-coli, have a life expectancy of 20+ years, and are easy to use and maintain. They are especially great for people with health problems, or those who live in remote areas where clean water is hard to get. Many folks place river water, or sea water, or other contaminated water into these stills in order to purify it.
How can I learn more?
The great thing about solar stills is that you can “make your own rain” at any time on any sunny day. Stills can be bought commercially at places like Solaqua.com or you can build the still yourself (Solaqua also has a kit for the hard-to-find items for around $200). The solar still construction plans from EPSEA can be bought through them as well.
Commercial or industrial-sized solar water distillers can also be purchased at suns-river.com or floonics.com
Don't forget the oldest running non-profit for solar energy in the country to learn more about solar energy, solar distillers, and more: epsea.org
Please "like" my solar book Facebook page that includes "How to make a solar water distiller": https://www.facebook.com/PassiveSolarEnergyHouseProjects
Lastly, you can learn the basics of how to make a solar water distiller by reading my book (it also covers earthtubes, passive solar home design, tornado-proofing your home, solar/wind energy, and solar ovens): https://www.createspace.com/3917111