Solar PV Pumping [Variable Frequency Drive]

---

A solar powered pump runs on photovoltaic energy instead of grid electricity or diesel fuel powered pumps. Solar powered pumps are more economical due to the lower operation and maintenance costs and also have less environmental impact than pumps powered by an internal combustion engine (ICE).

Solar pumps are useful where grid electricity is unavailable and alternative power sources (in particular wind) do not provide sufficient energy reliability.

A photovoltaic solar powered pump system has three main parts: solar panels, motor controller and pump. Solar panels make up about 70% of the systems cost. The purpose of the controller is twofold; it matches the output power that the pump receives from the solar panels; secondly it provides for low and high voltage protection that controls the pump in event of voltage over/under range. This increases the lifetime of the pump thus reducing the need for maintenance. Voltage of the solar pump motors can be AC (alternating current) or DC (direct current). Direct current motors are used for small to medium applications up to about 3 kW rating, and are suitable for applications such as garden fountains, landscaping, drinking water for livestock, or small irrigation projects.

Since DC systems tend to have overall higher efficiency levels than AC pumps of a similar size, the costs are reduced as smaller solar panels can be used. If an alternating current solar pump is used, an inverter is necessary that changes the direct current from the solar panels into alternating current for the pump. The supported power range of inverters extends from 0.15 to 100+ kW and can be used for larger irrigation systems. However, the solar PV panels and inverters must be sized accordingly to accommodate the inrush characteristic of an AC motor.

Solar powered water pumps can deliver drinking water as well as water for livestock or irrigation purposes. [1] Solar water pumps may be especially useful in small scale or community based irrigation, as large scale irrigation requires large volumes of water that in turn require a large solar PV array. [2] As the water may only be required during some parts of the year, a large PV array would provide excess energy that is not necessarily required, thus making the system inefficient.

Solar PV water pumping systems are used for irrigation and drinking water in India. The majority of the pumps are fitted with a 2000 watt - 3700 watt motor, a total of 1,200,000 solar PV water pumping systems have been installed in India up to 2016.