A farmer in the Cederberg region approached one of our local system integrators in the search of a more standard solar pump which can operate instead of his current 2.2kW grid tie pump. With most solar systems it is always important to calculate the return on investment. When taken the basic transformer cost and monthly usage into account it would still make sense to spend this amount on a off grid solar system.
Our Solution to the Problem:
For him to be completely off grid, a 4.5kW solar array with a 2.2kW H100 standard VFD from LSis were 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 allow the pump to start early in the morning and stop later in the afternoon. Another important feature is the realtime clock which switches the VFD completely off during night time.
This client now has the peace of mind that he gets the necessary local support from a local systems integrator that is only 30 km away. In the event of quick fault finding remote support is also available.