An Introduction to Solar Water Pumps – Part 1
A quick look at India’s electricity consumption profile shows that its agricultural sector is one of the largest electricity consumers. However, a huge chunck of this electricity comes from thermal power stations and diesel gensets – and is therefore carbon intensive and unsustainable.
Especially for water pumps, one of the key components of agricultural power consumption, solar energy makes perfect sense, given India’s abundant solar resource.
What Are Solar Water Pumps?
Solar water pumps consist of a pump and a motor set, a solar power conditioning unit (SPCU), solar PV modules, piping, cables, foundation material and an earthing kit.
The basic difference between solar water pumps and ordinary water pumps is that the motor of the former is run on solar generated electricity alone, while the later often runs on diesel. However, there is another key difference – for a given pump head, solar water pumps give variable water output, depending on the intensity of ambient sunlight.
Therefore their output is highest under strong sunlight and lower during the mornings and evenings, while a traditional water pump’s output (run on a diesel generator set) will be constant throughout its period of operation (provided there is ample availability of ground water).
Solar water pumps come in 3 key configurations:
1) Solar borewell submersible pumping system
2) Solar open well submersible pumping system
3) Solar surface pumping system
Their relative performance (indicative) is as the table under:
|Parameter||Solar borewell submersible||Solar surface||Solar open well submersible|
|Water output @ 5.5 kWh/sq.m./day solar insolation incident||2,500 to 750,000 litres per day||5,000 to 1,200,000 litres per day||35,000 to 600,000 litres per day|
|Total dynamic pump head||5 to 200 m||10 to 150 m||8 to 40 m|
|Solar modules wattage||500 to 30,000 Wp||500 to 28,000 Wp||500 to 10,000 Wp|
In Introduction to Solar Water Pumps – Part 2 we shall examine the HP ratings and costs of solar water pumps.
To read more about solar water pumps, click here.