What does solar cost in Perth in 2026?
Perth solar system prices have stabilised after a decade of rapid falls. Here's what a 6.6kW, 10kW, or 13.3kW system actually costs in 2026: what's included, what drives pricing, and how to evaluate a quote.
A 6.6kW solar system in Perth typically costs between $5,000 and $10,000 installed in mid-2026, depending on the panels and inverter. Larger 10kW and 13.3kW systems cost more, as the table below shows. Prices are after the STC discount (the federal solar discount) and include GST.
Before you ask for quotes, WattMate's free energy audit report works out which system size fits your home from your own bill.
How much does solar cost in Perth in 2026?
Between $5,000 and $18,000 installed in mid-2026, depending on system size and equipment. A 6.6kW system typically costs $5,000 to $10,000, a 10kW system $7,500 to $14,000, and a 13.3kW system $9,500 to $18,000. These are indicative prices, after the STC discount and including GST.
Prices below are for supply and installation, after the STC discount has been applied (installers apply the STC as a reduction at the point of sale).
| System size | Quote | Installed price range |
|---|---|---|
| 6.6kW solar only | Lower-priced quotes | $5,000–$7,500 |
| 6.6kW solar only | Higher-priced quotes | $7,500–$10,000 |
| 10kW solar only | Lower-priced quotes | $7,500–$10,500 |
| 10kW solar only | Higher-priced quotes | $10,500–$14,000 |
| 13.3kW solar only | Lower-priced quotes | $9,500–$13,000 |
| 13.3kW solar only | Higher-priced quotes | $13,000–$18,000 |
Prices are indicative for the Perth metropolitan area. Hills, regional and complex-access sites (steep roof pitches, multi-storey homes) attract labour surcharges.
What does the STC discount take off the price?
About $1,700 to $1,800 on a 6.6kW system, and it's already taken off the prices above. STCs (small-scale technology certificates) are credits your installer takes off the price at the point of sale. If a quote shows a "before STC" and "after STC" price, the "after STC" price is what you pay.
The size of the discount depends on system size. As of 2026, with a 5-year deeming period and a market price of around $39.90 per STC:
- 6.6kW system: approximately $1,700–$1,800 STC discount applied
- 10kW system: approximately $2,650–$2,750 STC discount applied
- 13.3kW system: approximately $3,550–$3,650 STC discount applied
Almost nobody pays the "before STC" number, so read it as a marketing figure rather than a price.
What makes solar quotes differ in price?
Four things move the price: the panels, the inverter, installer overhead and system complexity. Higher-priced panels and inverters and established local installers cost more, so check what the warranty and local support add for that price.
Start with the panels. Efficiency is how much sunlight a panel turns into power, and it ranges roughly 19–22% across current residential models. The spec sheet on each quote shows it, along with the degradation warranty (the guarantee on how slowly output may fall). On the inverter, monitoring and warranty terms vary by brand and model, so compare those too.
The installer is the next cost. Established Perth installers with in-house crews, apprentices and local service staff cost more than sole traders or interstate companies using subcontract crews. You're paying for something real: established installers are more likely to honour warranty call-outs 5–8 years after installation.
Then there's the job itself. Parallel strings for east/west arrays, three-phase inverters and service connections to underground boards all add cost. So does partial shading, because it calls for DC optimisers or microinverters, small devices that manage output panel by panel.
Why shouldn't you buy solar on price alone?
Because the lowest quote is almost always the lowest for a reason. A quote 20–30% below the others for the same specification deserves a closer look, not excitement. The usual reasons are entry-level components with shorter warranties and less local support, corners cut on the install (fewer fixings per panel, lower-grade sealants), or an installer more likely to go under or not respond to a warranty claim.
Get three quotes from SAA-accredited Perth installers and compare equivalent specifications: similar panel wattage and a comparable inverter model. That shows the market rate and where each installer sits against it.
If you already have quotes in hand, run each through WattMate's quote checker to see where it sits against the market, and how to negotiate a solar quote in Perth covers what movement to ask for. Still collecting? Get quotes from Perth installers in the WattMate network.
Why have solar prices stopped falling?
Perth solar prices fell by more than 70% in real terms between 2010 and 2022, then largely stabilised. The falls came from module manufacturing costs dropping fast (mostly in China), bigger installation volumes cutting the labour in each system, and a growing, competitive installer market.
Since 2022 those forces have run out of room. Module prices have reached manufacturing floor levels, so further falls are marginal. Labour costs in WA have risen with the broader construction boom, and supply chain and shipping costs have only partly settled. Homes are also buying bigger systems (10kW rather than 6.6kW), which lifts the average invoice. Dramatic falls like those of the 2010s are not expected to resume.
How do you judge solar value over the system's life?
A first-year payback figure is a poor guide to which system to buy. Judge solar and batteries over the system's life, around 25 years, when grid prices tend to rise. On that basis the answer often changes, as the three points below show.
- Solar only stays at 6.6kW of panels on a 5kW inverter, because that keeps DEBS (Synergy's solar export payment). A solar-only system past the DEBS cap earns nothing for its export.
- A bigger array with a battery often comes out ahead for a home that uses most of its power in the evening. With a battery connected, a hybrid inverter (one inverter that handles both solar and battery) can carry a bigger array, up to the inverter maker's maximum, and a 5kW hybrid still keeps DEBS.
- Battery size should match your evening and overnight use. Undersizing is the costlier mistake, because adding capacity later usually means a second installation.
Ask installers to price both designs on the same quote, then compare them on what they'll be worth over the years they keep working, not on the first year's bill.
For everything that comes off the price before you pay it (solar STCs, battery STCs, the WA battery rebate, DEBS), see the complete Perth solar rebates guide.
Next step: get your free energy audit report to see which design suits your home before you compare quotes.