Whilst this won’t be much use in your home, it’s an important piece of advice for those who find themselves stuck without enough drinking water somewhere remote, or those having to draw water from a well. Water found naturally in remote areas may look perfectly clear and clean to the human eye, but it can harbor literally millions of bacteria. The most common side effect of waterborne diseases is diarrhea, which can lead to further dehydration and death in severe cases. Indeed, the World Health Organisation states that such waterborne diseases account for nearly 2 million deaths each year – it is a very significant issue for much of the economically developing world. How can solar power be used to cut down this enormous risk of drinking un-sanitized water?

1. Make sure that you’re not dealing with muddy water or a source that could be contaminated with harmful chemicals – this will not help with them at all.
2. Take an ordinary plastic bottle, and remove all of the labels to make sure as much light can enter the bottle as possible. A clear bottle will be much more effective than a colored one.
3. Take off the bottle’s cap, and put a funnel into the bottle.
4. Cover the wide end of the funnel with a cloth, securing it with an elastic band or a hair tie. The aim is to use this cloth as a basic form of filter to try to remove particles of dirt.
5. Slowly pour water through the funnel into the bottle, taking care not to fill the bottle 100% – leave a small gap at the top for some air.
6. Lay down the bottle horizontally, on the most reflective surface you can find. This means that more of the sunlight will be reflected back into the bottle. In an ideal world. sit the horizontal bottle in a piece of tin foil with the edges curved up to try to direct the most light possible into the bottle. In the wild, light colored surfaces such as pale limestone rocks may be all that’s available.
7. Leave the bottle to sit for 6 hours. In the meantime, if it’s hot, find a shady spot to rest and reduce the onset of dehydration. This time may need to be extended to up to a day if it isn’t very sunny or it’s a cloudy day.

Many people think that boiling water is an adequate measure for ensuring it won’t cause them any harm. However, this method means that not only is the water heated up, the spectrum of UVA light introduced to the water can kill many pathogens. It is not recommended you do this regularly either – PET plastic as found in most drinks bottles can deform if it gets too hot, and it can release harmful chemicals into the water; you need to decide if this is a risk worth taking. Whilst we can take no responsibility for the water you drink having read this guide – it is, ultimately, your responsibility to make sure the water that you’re drinking is clean, hopefully this will reduce the risk.

Author: Written by James Hawkins from a UK solar panels cost comparison website. Whilst I usually write about solar power as a form of renewable energy, I thought these tips show how the sun can also be used to kill biological pathogens!