Saora Industries’ solar pumping concept integrates solar power into existing or new pumping applications for both irrigation and drinking water. The Solar Variable Speed Drive (svSd) Pv plant pumps in a Solar-Only Mode, or in Co-generation with existing diesel generators or public grids.
Consisting of photovoltaic modules and the solar variable Speed Drive, these systems drive the pump either at a constant head, or constant water flow rate. Most industrial water pumps can be operated with variable frequency drives, therefore the solar plant can be connected directly to the existing AC pump, so no other source of energy is needed.
With the PV system directly connected to the pump without the need of batteries, this reduces investment, operation and maintenance costs. The inverter is capable of forming an electric grid and running in a pure solar operation mode, which is the Solar-Only Mode.
Additional power sources in the form of a diesel genset or a public grid can be connected to co-power the pump during low irradiation periods. Driven by a 3-phase AC motor, the pump draws water from a deep well, and then feeds into a reservoir or a directly connected irrigation system.
The system operation is monitored and controlled by the solar pumping inverter, which uses an internal algorithm to adjust its output frequency according to solar irradiation levels in real time. This ensures that the whole system is constantly operating at its optimal levels, and maximizes the water flow (variable speed drive system of the pump). Then, it drives the pump by converting the DC power produced by the PV plant to AC power.
The pump’s performance curve can be derived from the characteristics of the pumping system. It determines the frequency at which the pump generates the minimum water flow required, which is typically from 30 to 50 Hz. The minimum power threshold and the operating capacity of the pump are defined according to the respective frequency, and the optimal size of the PV plant can then be concluded.