subject: Solar Water Distillation [print this page] I've been doing quite a bit of research recently into green technology, and in that research, I've come across a nifty little device called the solar water distiller, also known as the solar still. In recent days, solar energy has been exploding in popularity, and new technology is coming out all the time. But the solar water distiller isn't really a new technology at all, nor is it really a solar device, as most people think of solar. It does utilize sun energy and is thus a "solar" device, but it doesn't use solar cells or anything like it to distill water. The solar water distiller is more applicably titled the solar water still. The device basically uses sunlight to heat water, which then evaporates and condenses on the wide glass pane, and then drops down into a large glass bottle. In the process, solar water purification happens, and the water that comes out the spout is relatively clean. Solar water purification isn't complete purification however, because the water in the distiller is never boiled.
The solar water distiller, or solar still, really doesn't do anything more than trap and heat water, causing faster evaporation and by consequence condensation on the glass pane. The water is then collected in a specific way that keeps the water mostly pure and stored generally in a five gallon glass jug. In technical terms, it isn't really a solar water distillation device. It's more an evaporation device. The solar still's dimensions are generally around 5 feet long and two feet wide, and can be made of wood and glass, with jugs and silicone tubing - generally simple household items that have very little cost. But this is just a general dimension. There are many different sizes, even different solar water distiller designs. Some designs are clearly more complex than others, but they all rely on the same fundamental factor, which is sunlight.
Though the USA is going very quickly in the direction of green alternatives, in my opinion, the solar water distiller isn't really an applicable device for use here in America. It has a few drawbacks that generally cause a large concern. First off, the solar water distiller doesn't ever bring the water it collects to a boil, and therefore live bacteria and other hazards may still be present. Also, the solar water distiller has a difficult time retaining a good seal. Because of the large moist area it creates, the solar water distiller is often the target of insects and bacteria looking to exploit any weakness or opening in the seal.
That being said, however, the solar water distiller has great application for many third world countries. Having lived in a third world country myself (Cambodia) I know that fresh water can often be difficult to come by. During my stay in Southeast Asia, I would often drink the juice of unripe coconuts instead of the local water. The coconut provided a natural purification to the water, and the hard shell of the fruit kept the water preserved and pure. I'm intrigued by the idea of using solar water distillation in third world countries because the materials to construct them are very inexpensive, and simple distillers are easy to assemble. Not only that, but there are no moving parts to worry about, which makes it a handy little device.
It would be great to see solar water distillers used in third world countries worldwide. A compelling statistic lists a lack of fresh and clean water as one of the top causes of death worldwide, and literally millions of people every year die from lack of pure, clean water. Plans to build solar water distillers are available all over the internet, and generally, one can find plans that only use common household items for the construction. If you're wanting to build your own solar water distiller for home use, I encourage you to check out some of the cautions associated with the solar still.
