How does a SAPS affect SAIDI and SAIFI?

A SAPS removes the customer’s dependence on a long, fault-prone distribution feeder, which is why distributor led SAPS programmes are usually justified on reliability as much as on cost. The customers who receive SAPS are typically the worst-served on the network, end-of-feeder, high line-length-per-customer, slow to patrol and slow to restore, so their outage minutes carry disproportionate weight in network-level SAIDI and SAIFI.

Two design factors determine whether the improvement is realised in practice rather than on paper:

Redundancy inside the SAPS. A single-string system with one inverter and no generator has moved the single point of failure from the feeder to the site. Vantara is built with built-in redundancy and hot-swappable inverters, battery modules and chargers, so a component failure degrades output rather than removing supply.

Visibility. An unmonitored SAPS fails silently until the customer calls. A monitored one raises an alarm before the outage. The reliability benefit of a SAPS fleet is directly proportional to how quickly the network learns that a system needs attention.

Approximately 90% outage reduction on SAPS-served properties is a network’s own published figure, not a supplier claim. That distinction matters for a business case – it is a utility’s own assessment of its own performance.