Problem Background:

A farmer in the Cederberg region approached one of our local system integrators in the search of a solar water pump  – instead of his then 2.2kW grid-tie pump. With most solar systems it is always important to calculate the return on investment. When taking the basic transformer cost and monthly usage into account, it would still make sense to spend this amount on an off-grid solar system.

Our Solution to the Problem:

For him to be completely off-grid, a 4.5kW solar array along with a 2.2kW H100 standard VFD from LS Electric was required. The panels were connected directly to the VFDs DC bus, which can withstand up to 800Vdc. By making use of the built-in Multi Power Point Tracker of the VFD, the submersible speed gets reduced as the solar radiation reduces. This allows the pump to start early in the morning and stop later in the afternoon. Another important feature is the real-time clock which switches the VFD completely off during nighttime.

This client now has the peace of mind that he gets the necessary local support from a local system integrator that is only 30 km away. In the event of quick fault finding, remote support is also available.