According to the World Health Organisation (WHO), "at least" 1.8 billion people around the world still use a drinking water source that is contaminated with human waste. The WHO says that dirty drinking water causes an estimated 502,000 deaths from diarrhea a year.
In India, one non-profit organization is looking to the skies to purify water. SunSaluter have developed a "solar panel rotator" which follows the sun during daylight hours, boosting efficiency and producing clean drinking water simultaneously.
The potential of solar power as a clean energy source is significant: In 2014 the International Energy Agency stated that the sun could be the planet's biggest source of electricity by 2050.