A design company called NOS has developed a solution to two major problems facing developing countries: scarcity of drinking water and electricity. The concept is called the PhotoFlow, a combination solar photovoltaic device and rainwater harvester.

NOS says, "Most of the developing countries are located near the equator, receiving more sunlight and rainfall than most other countries on the planet. Despite this abundance, a large number of people living in these countries suffer from a lack of electricity and potable drinking water.

Building upon the designs of some existing rooftop water containers, we have created a simple device to collect both of these precious natural resources to meet the need for both electricity and drinking water."

The PhotoFlow is made up of eight identical triangular photovoltaic panels that are mounted on a 400-liter recycled polyethylene water tank. The panels form an octagon with a slope of 3 degrees that allows water to funnel into the central filter and be collected into the tank. To keep the water potable once it's collected, the inner layer of the tank is covered with a coating that controls levels of bacteria and fungi.