A question of clean water and solar power
When talking about global development, access to clean water is one of the most challenging issues. The United Nations reports that more than 780 million people in the world are living without any access to potable water (2012 data) and every year polluted water takes the lives of 3.4 million people. 99% of victims were living in developing countries.
Obviously, groundwater is the first solution to this issue. But one point remains. It is vital to drill deep wells to find cleaner water. A lot of people suffering from lack of water use wells which are only 50 metres deep, they are hand dug, easy to build and people can extract water using a simple hand-operated mechanical pulley. But these wells often quickly dry out or can be the source of polluted water, due to surface ground contamination or even an unsealed well opening.
So the deeper the well, the safer the water available for use. Deep wells are the most interesting solution, they are 100 meters deep and they are safer. But they cannot be exploited using a manual pump. And this is where electrical water pumps come into play but this comes with the added problem of needing electricity to work.
This is why electrical water pumps powered by an off-grid solar solution can be a realistic answer. An off-grid water pump can deliver between 20 and 50 m3 of water every day, which means between 2,000/5,000 litres from a single well. According to the World Health Organization between 50 and 100 litres of water per person per day are needed to cover the most basic needs of a single person. This means that one single solar water pump can deliver enough water for 500 – 1,000 people.
Another WHO study also fixes some standard water requirements for agriculture. For a vegetable garden, estimates stand at around 3-6 litres per square metre a day (one well with a solar water pump can therefore irrigate 660-1660 m2).