Solar Water Purification: A Starting Guide

Solar Water Purification: A Starting Guide

One of the biggest advantages of solar appliances is their off-grid hardiness. No need for powerlines or modern infrastructure when you can generate all the energy you need in situ. This makes solar appliances particularly helpful in places away from civilization or in areas with limited infrastructure. And since limited infrastructure and a lack of clean water often overlap, solar water disinfection is a perfect match. 

Solar water disinfection is a sort of portable water purification that cleans water through solar energy in order to remove contaminants such as bacteria, viruses, and protozoa. It does so through a mixture of electricity generated by solar PV panels, solar heating, or solar ultraviolet light collection. 

Most solar water purifiers use solar heat to warm water to a near boiling point for a short period of time. This can be done through the use of solar heat collectors or solar insulation. Once water is boiled, it is considered to be pasteurized water.

The potential for portable solar water purifiers is significant. According to the World Health Organization, over two million die of water-borne diseases annually. One billion do not have access to safe drinking water.  Solar water purification is considered an effective method of pathogen contaminant purification. This is due to the proven nature of the technology and the inexpensive ways by which such a solar water purifier can be built. 

A UNICEF document called "Promotion of Water Treatment and Safe Storage in UNICEF Wash Programmes" had this to say about solar water purification:

Solar disinfection, which combines thermal and UV radiation, has been repeatedly shown to be effective for eliminating microbial pathogens and reduce diarrhoeal morbidity (Hobbins 2004) including epidemic cholera (Conroy 2001). Among the most practical and economical is the “SODIS” system, developed and promoted by the Swiss Federal Institute for Environmental Science and Technology.

It consists of placing low turbidity (<30NTU) water in clear plastic bottles (normally 2L PET beverage bottles) after aerating it to increase oxygenation and exposing the bottles to the sun, usually by placing them on roofs. Exposure times vary from 6 to 48 hours depending on the intensity of sunlight. Like filters, thermal and solar disinfection do not provide residual protection against recontamination. Accordingly, householders must have a sufficient number of bottles to allow them to cool and maintain treated water in the bottles until it is actually consumed.

With all the potential that solar water purification offers, GoSun has plans to get in the game.

By the way – one of the best solar water purifiers you can find on the market is the GoSun Flow.

It's the world's first portable solar-powered purifier that produces enough clean water to wash dishes or even take a shower yet is small enough to fit in a backpack.

In 2020, GoSun has plans to work on products for water purification, tiny houses, and even a disaster response vehicle. Here's what GoSun founder Patrick Sherwin had to say in a recent podcast interview about riding this innovation wave in solar:

We're seeing solar's disruptive power. In these next couple of decades, we'll see explosive growth where solar is found everywhere. If you look at disruptive technological introductions throughout the century you see quick upticks -- like when the washing machine that was first introduced, it took about 10 years to fix the kinks. Once the early adopters bought it, it exploded in popularity. 

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