For a household using 28 kWh a day, about $865 a quarter at NSW's 30c a unit, the calculator puts 10–13kW solar at $7,670 to $12,670 after rebates, and 10–13kW solar + ~15kWh battery at $11,040 to $22,040.
I am an advisor, not an installer and not a lead broker. You pay nothing at any point.
See what my home should costA large household in a big house, someone home most days, using 28 kWh a day.
A ballpark for one example household, not a quote. The low end of each range is what a competitive installer charges; the high end is a poor quote for the same equipment. Prices are from the same calculator the free assessment uses, with NSW rates and rebates, and sun hours are its figure for New South Wales.
Four real households, run through the same calculator this site uses for an individual report. Panels only, no battery, clean roof, someone home some of the time. Prices are after every rebate that applies in New South Wales.
| Household uses | Their quarterly bill | System | After rebates | Saves a year | Pays for itself |
|---|---|---|---|---|---|
| 10 kWh | $373 | 5–6.6kW solar | $5,470 to $7,500 | $490–$730 | 9–10+ years |
| 15 kWh | $510 | 6.6kW solar | $6,250 to $8,250 | $650–$970 | 8–10 years |
| 22 kWh | $701 | 10–13kW solar | $8,000 to $13,000 | $1,020–$1,530 | 6–10 years |
| 30 kWh | $919 | 10–13kW solar | $8,000 to $13,000 | $1,230–$1,850 | 5–8 years |
The bill column is what that household actually pays in New South Wales at 30c a unit, which is why the same house has a different bill in every state. Savings depend on how much of the generation gets used on site rather than exported, and at 3.4c a unit for exports that is the number that decides the answer. A household out all day saves less than the figures above; one home most days saves more. Every figure is produced by the calculator, not written down, so it moves when the published rates move.
Killara is big houses in big gardens under a lot of trees, with apartment buildings along the railway line. The houses use a lot of power and many have someone home through the day, which is a strong case for solar, as long as the trees leave the roof any sun.
Your retailer sells you the power. Your distributor owns the poles and wires, and it is the distributor that decides how much solar you may send back to the grid. Killara is inside Ausgrid's network[1], so Ausgrid's rules are the ones a quote here should be designed to. Look for Ausgrid on your bill.
A choice from late 2026. Ausgrid is giving new and upgraded systems a choice. A flexible export connection is automatically approved to export up to 10kW per phase, and Ausgrid can turn it down when the local network needs it, to a minimum of 1.5kW per site. A fixed export connection is approved for 3kW per system and is never adjusted. Either way the inverter has to talk to Ausgrid over the internet; a house without a reliable connection gets a static limit of 1.5kW[2].
What that means in practice: flexible suits a bigger array that will have surplus most afternoons; fixed suits a house that uses most of what it makes and wants a number that never moves. Power the house uses, or a battery stores for the evening, is worth the full import price. Power that runs into the export limit is simply lost, and even what gets out earns only a few cents. So size the array to what the house uses, not to the size of the roof.
At the 2021 Census, 43.8% of occupied homes in Killara had four or more bedrooms, against 33.9% across New South Wales, and 39.4% were owned outright, against 31.5%. 42.6% of homes were flats or apartments.[3]
For the houses, the roof is usually big enough. Whether it sees the sun is the real question.
Things worth knowing before an installer walks the roof:
All of that describes the area, not your house. Two homes on the same street can be completely different jobs. Put your address in and the assessment works off the actual property rather than a town average.
A big roof under tall trees is often a small solar roof. Shade on part of a string of panels can drag down more than the shaded panels, depending on the inverter, so the design matters as much as the count. Ask how the installer handled shade: which faces, which months, and whether they used optimisers or microinverters where it matters.
Do not assume a tree can come out to make room. Removing or heavily pruning a significant tree can need council approval, so check with Ku-ring-gai Council before a design depends on it.
A household at home through the day uses a lot of its solar directly, which is the best case on any network. The first worked example below is that household.
If the house is a heritage item or in a heritage conservation area, panels on a roof that faces the main road and can be seen from it may need council approval. Panels out of sight from the road are exempt development under NSW planning rules[4].
These are examples, not an average for Killara. They are picked to show how the answer moves for the kinds of household the census shows are common here. Clean roof, no shading, NSW rates and rebates, and the battery prices assume it is installed before the federal battery discount steps down on 1 January 2027.
| Option | System | After rebates | Saves a year | Pays for itself |
|---|---|---|---|---|
| Change plan and cut waste first | No system | $0 | $170–$520 | Nothing to pay back |
| Solar panels only | 10–13kW solar | $7,670 to $12,670 | $1,420–$2,130 | 5–7 years |
| Solar plus a 10kWh battery | 10–13kW solar + 10kWh battery | $8,800 to $19,400 | $2,030–$2,860 | 4–8 years |
| Solar plus a 15kWh batteryPays back fastest | 10–13kW solar + ~15kWh battery | $11,040 to $22,040 | $2,310–$3,040 | 4–8 years |
Solar plus a 15kWh battery. It pays back fastest of the options open to you, which is the only measure here that accounts for what the thing actually costs.
Before any of it: get onto a competitive retail offer. It costs nothing, it takes an afternoon, and on a bill your size it is worth roughly $170 to $520 a year. Every payback below gets shorter once you are paying less per kWh, so it is worth doing first either way.
| Option | System | After rebates | Saves a year | Pays for itself |
|---|---|---|---|---|
| Change plan and cut waste first | No system | $0 | $120–$350 | Nothing to pay back |
| Solar panels only | 6.6kW solar | $5,960 to $7,960 | $730–$1,090 | 7–9 years |
| Solar plus a 10kWh batteryPays back fastest | 6.6kW solar + 10kWh battery | $7,540 to $15,440 | $1,340–$1,840 | 5–9 years |
Solar plus a 10kWh battery. It pays back fastest of the options open to you, which is the only measure here that accounts for what the thing actually costs.
Before any of it: get onto a competitive retail offer. It costs nothing, it takes an afternoon, and on a bill your size it is worth roughly $120 to $350 a year. Every payback below gets shorter once you are paying less per kWh, so it is worth doing first either way.
"Pays for itself" is the range between a competitive quote and a poor one for the same equipment, and 10+ means not inside ten years. The battery ranges are wide for the same reason. Your own usage, roof and timing will move every figure here, which is what the free assessment works from.
Applied by the installer as a discount on the quote, not something you claim. It scales with system size: on the 10–13kW solar in the first example above the calculator counts $2,330. It falls a little each year until the scheme ends in 2030.
There is no upfront state rebate on solar panels in New South Wales. There is the Home Energy Saver loan: interest-free, up to $15,000, repaid over up to ten years, for property owners, including landlords, with a combined taxable household income up to $210,000. Rooftop solar and batteries are both eligible, and the loans are delivered by Brighte and Plenti[5]. A separate discount of up to $4,000, for households earning up to $80,000 a year or holding an eligible concession card, has been announced but was not yet open on 26 October 2026[6]. The calculator leaves the loan out of every price, because it is repaid.
The federal Cheaper Home Batteries Program applies in NSW. On a 10kWh battery the calculator counts $2,520. The rate is set by the date the battery is installed, not when you order it, and it steps down on 1 January 2027 and every six months after that[7]. NSW's own battery discount under the Peak Demand Reduction Scheme is now only available through approved programs or on government sites, and NSW points battery owners to a separate incentive for joining a virtual power plant[8].
IPART's benchmark for a flat feed-in tariff in 2026-27 is 3.4 to 6.5c a unit, down from 4.8 to 7.3c the year before, and retailers do not have to pay it[9]. The calculator assumes 3.4c a unit, the bottom of that range, which is why every example on this page is decided by how much power the house uses itself.
The full breakdown, with dates, is in NSW solar rebates explained.
Already holding a quote? This is how I read one, line by line.
For the first example household on this page, 28 kWh a day, the calculator puts 10–13kW solar at $7,670 to $12,670 after NSW rebates, and 10–13kW solar + ~15kWh battery at $11,040 to $22,040. The range is the gap between a competitive installer and a poor quote for the same equipment. Your own figure depends on your usage and roof, which is what the free assessment works out.
Ausgrid. It sits inside Ausgrid's network, so Ausgrid sets your export limit, not your retailer. From late 2026, new and upgraded systems choose a flexible connection of up to 10kW per phase, which Ausgrid can turn down to 1.5kW per site when it needs to, or a fixed 3kW per system. Ask your installer which they have designed to before you sign.
It depends on the roof, not the suburb. A roof with clear sky through the middle of the day can do very well, especially for a household at home. A roof under tall trees can produce a fraction of that. The worked examples on this page assume no shading, so get a shading assessment at your address before relying on them.
The installer, and only when a job completes. Never the homeowner. No installer can buy placement, and nothing about you reaches one until you ask me to make the introduction.
About a minute. You get the system size, what it should cost, and what it saves. No one calls you unless you ask.
Start My Free CheckIndependent explainers on the parts of this that actually change the answer.
Prices, savings and paybacks come from this site's calculator, using NSW rates verified 2026-08. Everything else is from the sources below, read on the date shown. Rules and rebates change, so check the source before you rely on one.