Quick answer: Most Sydney quotes land on one of four standard sizes — 6.6kW (1–3 people, ~24–28 kWh/day), 10kW (growing usage and an EV, ~36–42 kWh/day), 13.2kW (pool, ducted air-con, full electrification, ~48–55 kWh/day) or 20kW+ (very large loads, three-phase, ~75–85 kWh/day). Anchor the choice to your actual daily usage, not the "popular" size.
Updated August 2026 for NSW residents.
Once you've worked out roughly how many panels you need (see our sizing calculator guide), it helps to see how the common "step" sizes actually compare side by side — because most quotes will land on one of a handful of standard sizes, and knowing what each one typically suits makes it much easier to sanity-check what you're being offered.
Solar systems aren't sized in perfectly round numbers — they're built from panels in fixed wattages, constrained by inverter export limits and STC eligibility bands. 6.6kW, 10kW, 13.2kW and 20kW (or thereabouts) have become the common reference points in the Australian market because they roughly align with single-phase inverter export limits, common three-phase configurations, and the practical roof-space steps most Sydney homes fall into.
| 6.6kW | 10kW | 13.2kW | 20kW | |
|---|---|---|---|---|
| Typical panel count (440W panels) | ~15 panels | ~23 panels | ~30 panels | ~45 panels |
| Approx. roof area needed | 33–37m² | 50–56m² | 65–72m² | 100m²+ |
| Typical daily generation (Sydney, north-facing) | ~24–28 kWh | ~36–42 kWh | ~48–55 kWh | ~75–85 kWh |
| Best suited to | 1–3 person households, moderate usage | 3–5 person households, some electrification | Larger households, pool, EV, ducted air-con | Very large households, home business, multiple EVs |
| Phase requirement | Single-phase (most homes) | Single or three-phase depending on inverter config | Often benefits from three-phase | Usually requires three-phase power |
| Typical Sydney install price range (before rebates)* | $4,500–$7,500 | $7,500–$11,000 | $10,000–$15,000 | $16,000+ |
*Indicative ranges only for premium equipment as of August 2026 — actual pricing depends on roof complexity, panel/inverter brand, and site-specific factors. Get an address-specific quote for accurate numbers. (Figures current as of August 2026 — these incentives step down on a set schedule; confirm current values before quoting.)
6.6kW became the de facto "standard" residential system size in Australia largely because it sits neatly under common single-phase inverter export limits in most network areas. It suits smaller households with moderate usage (roughly 15–22kWh/day) well, and remains the most common system size quoted for townhouses, units with suitable roof access, and smaller freestanding homes.
Where it falls short: households already using more than about 22–25kWh/day, or planning to add a pool, EV or a battery that needs meaningful daytime surplus to charge fully, will often find 6.6kW leaves real savings on the table.
10kW has become an increasingly common recommendation for family homes with moderate-to-high usage, particularly households that have electric hot water, ducted or multiple split-system air conditioning, or are planning to add an EV in the next few years. It also pairs well with most mid-sized batteries (10–13.5kWh), giving the battery enough surplus daytime generation to charge fully on most days rather than relying on the grid.
Where it falls short: households with genuinely small usage may struggle to self-consume enough of a 10kW system's output, exporting a larger share at low feed-in tariff rates — worth checking against your actual usage rather than assuming bigger is always better.
13.2kW (or similar, depending on exact panel wattage) suits larger households — commonly 5+ people, homes with a pool pump running daily, ducted air conditioning, or households actively electrifying (moving off gas cooking and heating onto electric, adding an EV). At this size, three-phase power starts to become genuinely advantageous for inverter selection and export flexibility, so it's worth checking your home's phase configuration early in the process.
Where it falls short: if your usage doesn't actually justify it, a 13kW system on a household using 15kWh/day will export the large majority of its generation at low feed-in rates rather than offsetting your bill — bigger isn't automatically better value.
Systems at 20kW and above typically suit very large households, homes running a business from the property (workshops, home offices with server/equipment loads), multiple EVs charging at home, or buyers deliberately future-proofing for full electrification over the next decade. These systems almost always require three-phase power and a more involved design process, including checking local network export limits, which can require a formal application in some cases.
| If you are... | Consider... |
|---|---|
| A 1–2 person household with moderate usage, no major upcoming changes | 6.6kW |
| A family household planning an EV or already running electric hot water/air-con | 10kW |
| A larger household with a pool, ducted air-con, or full electrification underway | 13.2kW |
| Running a home business, multiple EVs, or maximising long-term future-proofing | 20kW+ |
| Planning to add a battery within the next 1–3 years | Size up from your no-battery baseline to ensure enough daytime surplus to charge it |
It's tempting to assume the biggest system your roof and budget allow is automatically the best value, since STCs offset panel cost upfront regardless of size. But value depends on how much of what you generate you actually use or store. A household using 15kWh/day that installs 13kW of panels will export most of that generation to the grid at feed-in rates that are typically a fraction of the retail rate they'd otherwise pay — meaning the extra panels beyond a sensible size deliver comparatively poor payback unless a battery or future usage growth (EV, electrification) is genuinely part of the plan.
Use your actual daily usage (see our sizing guide) as the anchor, then look at where you sit on a 3–5 year horizon — not just today. A properly designed quote should explain, in writing, why a specific size was recommended for your household, referencing your usage and any planned changes, not just default to whatever's the "popular" size that month.
As a rough guide: 6.6kW suits 1–3 person households on moderate usage, 10kW suits growing family homes electrifying or planning an EV, 13.2kW suits larger households with a pool or ducted air-con, and 20kW+ suits very large loads or home businesses. Anchor the decision to your actual daily usage over a 3–5 year horizon rather than today alone.
Indicative pre-rebate ranges for premium equipment are roughly $4,500–$7,500 for 6.6kW, $7,500–$11,000 for 10kW, $10,000–$15,000 for 13.2kW and $16,000+ for 20kW. Actual pricing depends on roof complexity, brand and site factors, so get an address-specific quote. (Figures current as of August 2026 — these incentives step down on a set schedule; confirm current values before quoting.)
Three-phase starts to become genuinely advantageous around 13.2kW and is usually required at 20kW+. At 10kW it can go either way depending on the inverter configuration. Check your home's phase configuration early, because it affects inverter selection and export flexibility.
No. STCs offset panel cost upfront regardless of size, but value depends on how much you actually use or store. A household on 15 kWh/day with 13kW of panels will export most of that generation at low feed-in rates, so oversizing pays back poorly unless a battery or genuine future usage growth is part of the plan.
Want a size recommendation based on your actual usage and roof rather than a generic default? You can work it through with a Sydney-based team at blueenergysolar.com.au, or call 0421 458 217 / email sales@blueenergysolar.com.au.
