Solar Water Disinfection, or SODIS is a simple sun-based system for water disinfection that's designed to help prevent waterborne diseases in developing countries. But SODIS is a slow process — it can take up to 48 hours for UVA rays and heat to kill the pathogens in a small bottle of water. However, an Italian company has invented a bottle that's highly portable and that may speed up the disinfection process.
The solar bottle resembles a large flask. One side is clear, so the sun can shine through onto the water, while the other is metallic, which speeds the heating process. The bottle's adjustable handle lets it sit at the best angle for catching rays.
The SODIS system is meant for small quantities of water, but this bottle works with up to a gallon at a time because it's flat enough that the sun hits a large amount of the surface area. The concept recently won a 2007 INDEX award for its potential to "improve life." We hope it will be widely distributed — the bottles would work particularly well in conjunction with rotating houses.