Nandini Ramani, Sayan Maiti – Indian Institute of Management, Indore, India

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[1] “Jal” means Water and “Purn” means Complete in Sanskrit. “Jal Purn” will provide complete water solution [2]http://www.worldbank.org.in/external/default/main?pagePK=51187349&piPK=51189435&theSitePK=295584&menuPK=64187510&searchMenuPK=295612&theSitePK=295584&entityID=000090341_20060124094858&searchMenuPK=295612&theSitePK=295584 [3] Inspired from http://photoblog.msnbc.msn.com/_news/2012/02/16/10427642-solar-panels-atop-a-canal-in-india-aim-to-make-power-while-preventing-evaporation

Introduction

Water is a scarce resource and is available in limited quantities. According to a World Bank survey [2], unless

water is used judiciously, grave consequences await us in the future. The situation is worse in the rural areas.

The rural Indian farmer is mainly dependant on a good rainy season for fulfilling his water needs in activities

like agriculture, domestic usage and for drinking purposes. Such dependence often proves to be calamitous

for the rural farmer when the available water in a season is insufficient due to a poor rainy season. To

prevent such a scenario we propose a sustainable and complete low cost solution for the rural farmer which

takes care of all his needs. The main constituents of this system are –

In order to have sustainability in the sources of water, conservation is of utmost importance. When water is

taken from a source, a mechanism is used which ensures that 50% of the water is stored in a nearby tank and

only 50% is consumed. This is an idea which can be very easily implemented in Indian villages. The primary

source of water in Indian villages is the mechanical hand-pump or the well. When users pump the hand-

pump, half the water comes from the pump while the other half is stored in an underground tank. The water

stored in tank can be used for sanitation, irrigation and other purposes. By implementing a mechanism like

this, one can ensure that a running tap or hand-pump does not result in wastage of water.

An underground tank of capacity 500-1000 liters’ will be used to store the water from different sources. The

tank will be made of lined carbon steel and it will receive water from the mechanical pump as well as

rainwater harvesting. The tank will have a mesh/filter which will prevent large contamination from entering

the tank. If the tank is filled up, an indicator will alert the farmer, who can use the excess water for irrigation.

The tank will be covered to prevent air contamination.

A solar panel will be used to cover the underground tank. The solar panel cover will serve a dual purpose. It

will prevent the evaporation of water. It will also generate power which will be used for various purposes

like heating water, pumping water for irrigation, solar water purification and emergency pumping needs like

pumping water from underground to the tank.

“Jal Purn[1]” - The complete water solution for the rural Indian farmer

Source of water – A mechanical hand-pump with backup power pumping facility

A solar panel [3] used to cover the tank and provide source of energy

An underground tank used to store water

2 [4] http://www.sodis.ch/index_EN

The rainwater harvesting system will be equipped with a filter(sand, bricks etc) to remove contamination

such as harmful minerals and solid particles. The filtered water will enter the storage tank through a pipe.

Solar rays are extremely potent in purifying water by killing bacteria. The UV-A component of solar radiation

interferes with the metabolism of bacteria and destroys their cell structure. The UV-A also reacts with

oxygen dissolved in the water and produces highly reactive types of oxygen which further inhibit the growth

of pathogens. In addition to this, solar radiation heats the water, which speeds up the disinfection process.

On an average, by storing water in Polyethylene Terephthalate(PET) bottles, the water can be purified in 6

hours on a sunny (<50% cloud cover) day. Since the bacteria may grow back after the water has been

removed from the presence of solar radiation, this method of disinfection can be carried out with titanium

dioxide over glass cylinders. By harnessing the potential of solar energy in purifying water, sustainability can

be achieved. The method which is also called SODIS[4] ( Solar water disinfection ) can be done for cheap and

effective purification of water.

Conclusion

For financing the scheme, tie-ups can be done with local microfinance institutions and banks for getting easy

loans. The complete system is low cost with only the solar panels covering most of the costs. Moreover

community systems can be built where 5-10 or more families pool up to purchase this system. In such cases,

larger tanks and solar panels will be used and economies of scale will bring down the overall cost of the

system. Moreover energy from biogas systems can also be coupled with the systems in case solar power is

unable to satisfy the energy needs. The advantage is the system is that it will make the water needs of the

rural population self sufficient. Moreover it will result in clean and renewable solar energy without any

transmission losses as the power generated will be used for local use. Such a system is both feasible and

affordable for the rural population. If it succeeds it can be replicated in many other countries in South East

Asia where water is a scarce commodity.

Schneider electric can build such systems for the rural population which are easily affordable and

have low maintenance costs.

A rainwater harvesting system with purification system to collect only clean water

A purification system based on solar energy