Cost of Solar Panels Calculator (Australia)

How to use this calculator

The calculator turns your usage into a kW system size, then prices it at Australian after-STC market rates. Five inputs:

1. Monthly electricity use (kWh) — pull from your AGL, Origin, EnergyAustralia or local retailer bill or My Electricity Tracker. The 2026 AER residential average ranges from 380 kWh/month (apartments) to 700 kWh/month (4-bed detached with ducted A/C). Add 250 to 350 kWh/month for an EV; add 200 to 400 kWh/month if your hot water is electric instead of gas/heat-pump.
2. Target offset (%) — 100% means a system sized to match annual usage. Most Australian homes should target 120 to 150% to maximise solar exports during high midday production, since residential FiTs (5 to 10c/kWh) are well below import tariffs (28 to 38c/kWh) — every exported kWh is worth less than every self-consumed kWh, but solar oversizing is still net-positive against zero-import alternatives.
3. Peak sun hours/day — Australian annual averages: Brisbane 4.8, Sydney 4.3, Melbourne 3.9, Adelaide 4.4, Perth 4.7, Darwin 5.7, Hobart 3.6, Canberra 4.4. The Clean Energy Council and Bureau of Meteorology peak-sun-hour atlas is the reference.
4. Installed cost per watt (after STCs) — the 2026 SunWiz median is A$1.05/W for 6 to 10 kW systems, dropping to A$0.95/W at 10 to 15 kW. Use your actual quoted figure when shopping — quotes below A$0.85/W usually flag inferior panels (Tier-2 brands like Risen, Longi non-Hi-MO) or string inverters with no rapid shutdown.
5. Additional rebate (%) — leave at 0 since STCs are baked into the after-STC price field. Add state rebates: Solar Victoria Solar Homes (A$1,400 panel rebate, means-tested), NSW Empowering Homes (interest-free loan up to A$14,000), ACT Sustainable Household Scheme (zero-interest loan up to A$15,000), or SA Home Battery Scheme.

How the math works

annual_target_kWh = monthly_kWh × 12 × (offset% / 100)
system_kW         = annual_target_kWh / (peak_sun_hours × 365 × 0.78)
gross_cost        = system_kW × 1000 × A$/W (already net of STCs)
range_low/high    = gross_cost × 0.85 / 1.15

Worked example for a Sydney home using 600 kWh/month:

• Annual target: 600 × 12 × 1.0 = 7,200 kWh
• System size: 7,200 / (4.3 × 365 × 0.78) = 5.88 kW
• After-STC cost at A$1.05/W: 5,880 × A$1.05 = A$6,174
• Typical range: A$5,248 to A$7,100

Australian cost-per-watt by capital city (2026)

SunWiz and Clean Energy Council market data, median CEC-installed price, after STC rebate:

Sources: SunWiz Solar Insights H2 2025, Clean Energy Council quote aggregator, hipages.com.au tradesperson quote panel.

What is and is not included in A$/W

A typical A$1.05/W after-STC turnkey quote includes:

• Tier-1 panels CEC-listed (Trina Solar, Q CELLS, JA Solar, Longi Hi-MO, REC, Jinko)
• CEC-listed inverter (Fronius, Sungrow, Goodwe, Solis, SMA)
• Compliance with AS/NZS 5033 (PV array installation) and AS/NZS 4777.2 (grid connection)
• Distributor application (Form A or A+) and meter reconfiguration
• Clean Energy Regulator STC creation and assignment
• DC isolator (mid-2024 onward: rooftop isolator removed under AS/NZS 5033:2021), AC isolator
• Standard tile or tin roof mounting (Schletter, Sun Wedge, Fast Pak)
• 10-year manufacturer panel warranty (Tier-1 minimum), 10-year inverter warranty
• 5-year workmanship warranty under CEC retailer code

What it does not include:

• Switchboard upgrade — A$800 to A$2,000 (common in pre-2000 homes)
• Three-phase upgrade — A$3,500 to A$6,500 (sometimes required for over-10kW systems)
• Tile-roof premium — A$500 to A$1,200 (Bramac, Monier extra labour)
• Two-storey height premium — A$400 to A$1,000 (scaffolding/EWP hire)
• Battery — A$8,000 to A$12,000 for 10-13.5 kWh after Cheaper Home Batteries discount
• Smart meter if not already installed — A$0 to A$300 (usually free in NEM jurisdictions)

Solar feed-in tariffs by state (2026)

Most state regulators have abolished mandated minimum FiTs, but typical retailer offers in 2026:

• NSW — 4.0 to 8.0c/kWh (deregulated; AGL, Origin, Engie, Red Energy)
• VIC — 3.3c/kWh (Essential Services Commission single rate); 8 to 12c on premium retailer plans
• QLD — 4.5 to 12c/kWh (Energex/Ergon Regional FiT plus retailer top-up)
• SA — 4.0 to 8.5c/kWh (deregulated)
• WA — 2.25c/kWh peak / 10c/kWh peak (Synergy DEBS time-of-export)
• TAS — 8.74c/kWh (Aurora Energy regulated)
• ACT — 6.0 to 10c/kWh (deregulated)

FiTs have declined steadily since 2017 — the math now strongly favours self-consumption. A 13.5 kWh battery shifts 5 to 7 kWh/day from 4c export to 30c+ self-consumption, often turning the battery cash-positive over its 10-year warranty.

Pair this with the payback calculator, ROI calculator, and savings calculator

Cost gives you the up-front outlay; payback tells you when you break even (typically 4 to 7 years in Australia — fastest in the OECD); ROI gives you the lifetime return; savings shows you the year-over-year cash flow.

Sources

• Clean Energy Council retailer code — accredited installer database
• SunWiz Solar Insights H2 2025 — installed pricing trends by state
• AER Default Market Offer 2025-26 — retail electricity rate benchmarks
• Clean Energy Regulator — STC scheme — STC pricing and deeming rules
• DCCEEW Cheaper Home Batteries Program — federal battery rebate
• Bureau of Meteorology solar exposure — peak sun hours by region
• hipages solar cost guide — adder pricing data