| 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 | $1,379 | $3,421 |
| Victoria | Zone 4 | $1,182 | $3,618 |
| Queensland | Zone 2 | $1,379 | $3,421 |
| South Australia | Zone 3 | $1,379 | $3,421 |
| Western Australia | Zone 3 | $1,379 | $3,421 |
| Tasmania | Zone 4 | $1,089 | $3,711 |
| Australian Capital Territory | Zone 4 | $1,182 | $3,618 |
| Northern Territory | Zone 1 | $1,618 | $3,182 |
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 $1,379 in Sydney/NSW, varying by state), most households pay roughly $3,421 to $5,121 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.