Description/ Specification of Solar Pump

Solar pumps are driven by electrical energy generated by photovoltaic cells applying the principle of photo electricity and using sunrays incident on them. Large number of solar cells are connected together in solar panels, and in turn a number of solar panels combine to form a solar array. The more sunshine the panels receive, the more electricity they produce. The electricity so generated is used to drive water pumps which lift the water from a source like a pond /river or well and send it up to the point of consumption . They can be used for irrigation, storage, cleaning, washing or any other use. Since electricity is generated only when sunlight is available, any surplus electricity can be stored in a battery bank and later drawn from it as and when required. Alternatively , water can also be stored in an overhead tank and used later. The electric current produced by solar energy is DC or direct current. If the pump to be driven is also DC , then no conversion is required. Otherwise, it has to be converted into AC power using an inverter. A controller is used in the circuit which is placed between the Solar panel and pump. It serves multiple purpose like starting and stopping of the pump, protecting the pump in case of low water level etc. Advantages of Solar pumps: Since they run on solar energy, they do not produce any harmful exhaust like diesel driven pumps. As compared to grid power driven pumps, they do not need any connection to local grid , which can be costly and cumbersome in case of remote areas. Also, they are more reliable as grid power is often not available or do not always offer proper voltage , frequency etc. Since the Solar panels have no moving parts, they require very little maintenance, except for the occasional cleaning. Another advantage is that solar panels generate the maximum power during summer days when the need for water is also maximum for both agricultural and non-agricultural purposes. While solar pumping systems are costlier to install, their operating cost is much lower. Size and type Of solar pumps: The size of solar pump depends on factors like quantity of water to be pumped, the height over which it is to be lifted, and the distance over which it is to be transported up to the point of consumption or local storage. The amount of pumping power required, and the available solar incidence will determine the size of the solar array. For low power consumption, DC pumps are more suitable. In that case DC power can directly be consumed. Addition of a battery bank also creates provision for storage of electricity for use later during evening hours. However, for larger irrigation projects, centrifugal pumps of higher capacity which are normally driven by AC power, are more suitable. In that case, cost goes up as inverter is also required. Solar pumps can be of submersible type or surface type. Submersible solar pumps lift the water over a height from an underground source like a well or a borehole. They can typically lift water up to a height of 50 meters. Surface pumps can pump water from sources like pond, River, shallow well etc, which does not require much lifting power. Solar water pumps are an ecofriendly, cost effective , and easy to operate alternative to conventional pumps. They are beneficial for agriculture, domestic, and animal husbandry purposes particularly in rural areas. Below are listed some companies in India who offer these pumps.