Solar water pump systems: an introduction

Private households and farms need stable and consistent water supply, however this can be particularly difficult in areas far off cities where there are no regular city-like water pipe supply systems available but only resources in forms of wells deep in the ground. During hot months and in hot areas the requirement for water is high.

Moreover, in some scarcely inhabited areas where regular irrigation for watering feels is crucial, often meager electricity infrastructure makes regular irrigation complicated, significantly driving operational and maintenance costs. Countering such complications and difficulties, solar water pumps are the optimal solution to both offset infrastructural limitations and reduce operational/ maintenance costs.

Solar water pump system – technical outline

A solar energy-powered water pump is a water pump running on the electricity that is generated by solar photovoltaic modules.

Using solar energy as power source, such solar water pumps basically consist of three main components:

1) the water pump
2) solar photovoltaic modules
3) pump controller (and inverter)

A water pump basically is an electro-mechanical device that moves water by mechanical action and powered by an electricity generating source, which can be manifold, such as diesel engines, wind power or solar energy. According to the water table level, distance to move the water and the pumping quantity requirements, different type sizes of water pumps apply.

The major  pump types are surface-mounted pumps and submersible (deep-well) pumps – as shallow-well water pumping requirements are different from those for deep-well water pumping. In latter situations of wells deep in the ground, it makes much more sens to put the water pump near to the well source in order to basically push up the water.

The water pumping amount requirements (m³/d), electricity supply and sun irradiance conditions determine the overall size of the PV system and thus the output power and quantity of solar photovoltaic modules needed.

The pump controller is another important component of the system. It matches the output and input power of the pump and solar panels and also provides voltage protection. With the pump controller the operator adjusts the pump pressure, flow, frequency, operational times etc. According to the end use requirements, there are various categories of pump controllers to choose from, depending on the solar pump motors (AC or DC).

Advanced pump controllers come with integrated inverter functions, needed for AC solar pump motors, as well as network communication functions which enable off-site supervision and operational adjustment of the solar water pump.

Applications of solar water pumps

According to each individual need, solar water pumps can be applied for a range of different purposes where pumping water is needed. Main applications include:

a) crop and plant irrigation
b) drinking and cooking water supply
c) swimming pools
d) industrial water processing
e) fountains
f) irrigation for Farming
g) drinking Water for Livestock
h) swimming pools

Correct sizing of the pump, motor and controlling devices as well as detailed system design according to the location and usage of the solar water pump is essential to guarantee the optimal system performance and to avoid risks at water supply that may harm people, animals and crops.

Conclusion

Due to their significantly lower operational and maintenance costs, minimized environmental impacts and multi-geographic application ability, solar water pumps are particularly economic and crucial appliances especially for residents living off-grid, off-grid farmers or overall for both commercial and residential use in countries with weak electricity and water supply infrastructure.