What is the difference between a SAPS and off-grid solar?

Technically they overlap; commercially they are different products for different buyers. “Off-grid solar” generally describes a system serving a premises that chose not to connect. “SAPS” is the utility and infrastructure term, and it carries expectations that off-grid solar usually does not: a defined reliability standard, redundancy, remote monitoring, SCADA integration, and in the distributor-led case a regulatory framework governing the customer’s rights. Same physics, different specification.