The boiling point of water is 212° F or 100° C, but the pasteurization point of water is 149° F or 65° C. That's a tremendous amount of savings of both time and energy, and can be easily achieved through solar cooking techniques as well as the traditional "pot on the fire" method.
However, a significant drawback to pasteurization is that, unlike boiling, there is no visual indicator for when water has reached that point. This is easily corrected with the purchase or manufacture of a Water Pasteurization Indicator, or WaPI.
Contrary to what many people believe, it is not necessary to boil water to make it safe to drink. Heating water to 65° C (149° F) for 6 minutes, or to a higher temperature for a shorter time, will kill all germs, viruses, and parasites. This process is called pasteurization.
In this document we describe several pasteurization techniques applicable to developing countries. Pasteurization is not the only technique that can be used to make water safe to drink. Chlorination, ultraviolet disinfection, and the use of a properly constructed, properly maintained well are other ways of providing clean water that may be more appropriate, particularly if a large amount of water is needed. Conversely, if a relatively small amount of water is needed, pasteurization systems have the advantage of being able to be scaled down with a corresponding decrease in cost. In other words, if you have only a little money, you can use pasteurization to get a little clean water, perhaps enough for a family but not a village. As always, the selection of the right system should be based on local conditions.