In Indonesia, Panasonic found that fridges need big compartments to store lots of two-litre water bottles: Indonesians boil water to purify it in the morning and then place it in the fridge to cool.
I never would have imagined that people who are in a position to buy a refrigerator, and have access to a steady power supply, would not have access to clean water. But it makes sense; you can get a cheap fridge for about $40 and power can be fairly easy to generate, but it takes a well-functioning government to supply clean water or produce the conditions for a reliable private supply.
What this means is that there is a market for a cheap, efficient electric water purifier, something that is more convenient and uses less fuel than boiling water on a stove. It would probably be something like a coffee maker, you would pour water in the top and it heats it and sends it through a filter to produce a bottle of clean water.