HowmuchdoesInverter&BatteryBackupcostinRobbenIslandVillage?

Size on usable kWh of essential evening load, not headline VA. A household running fridge, lights, Wi-Fi, TV and phones for a 4-hour Stage 6 block needs about 3–5 usable kWh of battery and a 5 kVA inverter to cover the surge from compressor starts. Add a geyser or a heater to that essential list and the numbers roughly double.

An inverter without a battery does nothing during load-shedding — it's just a pass-through. The battery is what carries the load; the inverter manages the handover and the waveform. If you're spec'ing for Stage 6 winter peak outages, plan the battery first (kWh of evening load) and let that determine the inverter size, not the other way around.

A quality lithium pack (LiFePO4 chemistry) gives 4,000–6,000 cycles to 80% State-of-Health — roughly 10–12 winter peak seasons under daily Stage 6 cycling. Lead-acid (deep-cycle AGM) gives 500–800 cycles — typically 2–3 winter peaks before noticeable capacity loss. The lifecycle cost of lithium is lower despite the higher upfront price, especially under heavy cycling.

Yes — any installation that ties into the household DB-board requires a Department of Labour electrical CoC, regardless of whether solar panels are involved. NRS 097-2-1 grid-tie compliance only applies if the inverter ever exports to the grid (hybrid systems). A plug-and-play UPS that doesn't touch the DB-board is the only exception, and those are limited to small loads.