Oversizing a residential solar system means paying for panels that mostly export at a low feed-in tariff instead of offsetting your retail rate. Undersizing means missing easy savings. The right number depends on your property type, your bill, and your electrical supply — not a single "average home" figure.
Typical system sizes by property type
| Property type | Typical system size | Indicative cost* |
|---|---|---|
| Small home (1–2 bed, low daytime usage) | 3–6.6 kW | $2,500–$5,400 |
| Medium home (3–4 bed, family usage) | 6.6–10 kW | $5,400–$8,200 |
| Large home (4+ bed, pool/EV/AC-heavy) | 10–13.2 kW | $8,200–$10,900 |
| Acreage / rural | 13–30 kW | $10,700–$24,700 |
| Commercial | Custom, load-audited | Quoted per site |
*Indicative only at $824/kW, excludes battery — see our pricing guide for the full breakdown. Get a size tailored to your bill on the calculator.
Sizing to your actual bill
A useful rule of thumb: in the Canberra/South-East NSW region, each kW of panels generates roughly 1,350 kWh per year. If your household uses (say) 6,500 kWh/year, a system in the 4.5–6.6kW range will cover most of that — going much larger just increases the share of generation you're exporting at a low feed-in tariff rather than using directly.
Single phase vs. three phase — why it caps your system size
Your home's electrical supply directly limits inverter size:
- Single phase is standard in most homes and typically supports inverters up to roughly 5–10kW, depending on your network's export limits.
- Three phase is common in larger homes, rural properties and commercial buildings, and removes that ceiling — allowing larger systems without being capped by single-phase export limits.
If you're on single phase and want a system larger than your network's export limit allows, a single-to-three-phase upgrade is sometimes worthwhile — we assess this during your free site inspection.
Acreage & rural properties: sizing differently
Rural and acreage properties often run larger loads (bore pumps, workshops, multiple outbuildings) and have the roof space to match — systems from 13kW up to 30kW are common. These properties also see the most benefit from batteries and, in some cases, off-grid setups where grid connection is impractical — see our off-grid guide if that applies to you.
Get your exact system size
Our calculator sizes a system to your property type, bill and usage pattern in under a minute.
Should sizing account for a battery too?
Yes — if you're planning a battery, it's worth sizing your panel array slightly larger than a battery-free system would need, so there's enough daytime generation to both run the house and charge the battery. See our battery storage guide for how that trade-off plays out financially.
