LORENTZ PSk is a family of solar water pumping systems for larger-scale projects. When more water is needed than solar power can provide, for example 24 hour pumping, PSk becomes a true hybrid system. Instead of just switching from one source to another, the PSk will automatically blend grid or generator power with the core solar power supply. The PSk also manages generator auto start and stop, timed starts, and also volume based, level based or pressure based decision making. PSk systems are available from 5.5kW to 100kW with a wide range of submersible and surface pumps and motors. The PSk controllers can also be used to retro-fit an existing AC pump to run off solar.