While most new inventions are for wealthy people, with some social status, once in a while there are inventions aimed to help the poor and provide the minimal sanitary conditions through simple and inexpensive methods. To get one liter of boiling water you need one kilo of firewood. People living in areas with no safe water usually spend 3-10% of total income/year on water.
One such method has been invented by Petra Wadstrom from Sweden. The invention’s purpose is to purify the drinking water ten liters at a time. The amazingly simple and effective invention is called Solvatten (meaning “sun water” in Swedish), and it’s using the Sun to heat the water to 55°C, providing important disinfection from several pathogens, including the feared E-coli bacteria. The device also features a water filter to provide a macro cleaning of impurities.
The Solvatten is very easy to use: you just pour 10 liters of water inside, leave it in the open Sun for 3-4 hours. An indicator turning from red to green will tell you when it’s safe to drink the water. The inventor says water samples with more than 200.000 E-coli / 100 ml (quite a concentration) have been treated successfully.
From their site: “In 2009 the first units of SOLVATTEN will reach Nepal for a user study. A program will be run in a number of families, schools and health centers in Nepal. The program is being implemented in collaboration with UN-Habitat and ENPHO.”