Generators get bought on price and regretted on performance. Too small and it overloads and stalls; too big and you burn fuel for capacity you never use. Here is how to size one properly for your home — and whether you should buy one at all.
Size to your essential load
List what genuinely must run at the same time and total the running watts, then add headroom for motors that surge on start-up (fridge, pump):
- 2–3kVA — lights, Wi-Fi, TV, fridge.
- 5kVA — the above plus a microwave or pump.
- 8kVA+ — whole-house with heavier loads.
Generator or inverter?
A generator runs as long as you have fuel and handles heavy loads — but it is noisy, needs fuel, and needs starting (unless automated). An inverter with battery is silent, automatic and maintenance-free, limited only by battery size. Many Johannesburg homes prefer an inverter for everyday load-shedding and keep a generator for extended outages.
Never back-feed a generator
A generator must connect through a proper changeover switch installed by a registered electrician — never through a wall plug, which is dangerous and illegal (here's why).
Let us size it with you
We will work through your essential loads and recommend a generator or inverter that keeps them running, installed and certified. Get a backup-power assessment.