This not only makes it easy for people to keep WEDEW running in developing regions, it helps the environment. The gassifier can use dead biomass that might otherwise catch fire and release CO2. Its output is ideal, too. It creates a warm, humid environment ideal for water harvesting, and it outputs a form of charcoal that can foster plant life and store carbon. If that's not an option, solar power and batteries are available as alternatives.

The non-biomass version of WEDEW is already in use -- the prize will help develop and launch biomass-powered units through team-ups with non-profit groups. It would primarily be useful for places where water is scarce, expensive or both, but it could also be essential for relief in the wake of a disaster, when clean water may be virtually non-existent.