There are applications where the need for water cannot be met with solar power and water storage alone. There may also be a need for specific seasonal demands, constant pressure or constant flow which might not be economically met with a direct solar solution. In both of these cases the SmartPSUk2 allows the PSk2 systems to be powered by an AC generator or grid mains supply.
 
The solar array is connected to the SmartPSUk2 and the AC supply is also connected to the Smart PSU. The SmartPSUk2 then powers the PSk2 system with DC power.