| Panel count (typical) | 15 panels at ~440 W each |
| Inverter | 5 kW |
| Typical retail price | $4,800–$6,500 |
| Annual generation | ~7,250 kWh / yr |
| Daily generation | ~20 kWh / day |
| Roof area needed | About 25 m² of north-facing roof |
| Suits | 1–2 people, Under $300 / quarter |
| Typical payback | 4–5 years |
Federal STC rebate on a 5 kW system, by state
The federal STC rebate scales with system size and STC zone. Here's what a 5 kW install attracts in each state in 2026:
| State | STC zone | Federal STC rebate | Net price (low end) |
|---|---|---|---|
| New South Wales | Zone 3 | $1,050 | $3,750 |
| Victoria | Zone 4 | $901 | $3,899 |
| Queensland | Zone 2 | $1,050 | $3,750 |
| South Australia | Zone 3 | $1,050 | $3,750 |
| Western Australia | Zone 3 | $1,050 | $3,750 |
| Tasmania | Zone 4 | $830 | $3,970 |
| Australian Capital Territory | Zone 4 | $901 | $3,899 |
| Northern Territory | Zone 1 | $1,233 | $3,567 |
Add state-specific rebates on top where applicable. The ACT and NSW stacks typically reduce net cost another $1,600–$2,500.
How a 5 kW system performs day-to-day
On a clear summer day in Sydney or Brisbane, a 5 kW system produces around 27 kWh. On an overcast winter day in Melbourne, it might produce 10 kWh. Annual average is about 20 kWh per day.
For most homes, around 30–40% of that generation is consumed at home in real time. The rest is exported to the grid (and earns the feed-in tariff). Adding a battery typically pushes self-consumption to 80–90%.
Who a 5 kW system actually suits
We get this question on every specialist follow-up. Quick rule of thumb based on quarterly bill size:
- 5 kW — Under $300 / quarter · 1–2 people
- 6.6 kW — $300–$600 / quarter · 3–4 people
- 8 kW — $500–$800 / quarter · 4–5 people
- 10 kW — $700–$1,000 / quarter · 4–6 people
- 13.2 kW — $900+ / quarter · Large families, all-electric homes, or EV households
These are starting points. Other factors that bump you up or down: daytime usage (pool, EV, electric hot water), planned future loads (EV in the next 2 years pushes you up a size), shading, and roof orientation.
Common questions about 5 kW solar
How much does a 5 kW solar system cost in 2026?
Fully installed, a 5 kW system costs between $4,800 and $6,500 retail before rebates. After the federal STC rebate (around $1,050 in Sydney/NSW, varying by state), most households pay roughly $3,750 to $5,450 net.
How much electricity does a 5 kW solar system generate?
A 5 kW system generates roughly 7,250 kWh per year on average in Australia — that's about 20 kWh per day. Output varies ±20% depending on location, roof orientation, and shading.
Who is a 5 kW system suitable for?
1–2 people households with quarterly bills in the Under $300 / quarter range. You need roughly About 25 m² of north-facing roof. The smallest mainstream residential system. Suits couples and small families on modest bills, or apartments and townhouses with limited roof area.
What inverter pairs with a 5 kW solar system?
A 5 kW inverter is the standard pairing. The "oversized DC" approach (panels rated higher than the inverter) is legitimate — it captures more STC rebate (which is calculated on panel capacity) without significant real-world clipping.
Should I add a battery to a 5 kW system?
Batteries are optional for a 5 kW system but rarely cost-effective at this size — daytime self-consumption is usually high enough that the marginal benefit is modest. If you're considering one, a 6.6 kW + battery combo usually pays back faster.
Get matched with a 5 kW installer
Free for homeowners. We pair you with one CEC-accredited installer who works your postcode, applies every rebate at point of sale, and stays accountable through to install.