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Solar Feed-in Bill Savings Calculator (Australia)

Calculate your annual electricity bill savings under Australian solar feed-in tariffs. State-by-state FIT comparison, DMO retail rates, and battery economics for 2026.

Prepared by the Solar Calculator HQ editorial team. Review our formula, source and limitation standards.

Solar Feed-in Bill Savings Calculator

Bill without solar
$2,312
Bill with solar
$1,190
Annual savings
$1,122
Bill reduction
48.5%
How the math works
Annual production: 7,791 kWh
Annual imports: 4,463 kWh · Annual exports: 5,453 kWh
Bill without solar: $2,312 → Bill with solar: $1,190

How the calculator works

The Solar Feed-in Bill Savings Calculator estimates your total annual benefit from a domestic rooftop PV system under Australia’s gross-metering-plus-FIT model. It separates the two revenue streams:

  • Avoided imports — solar kWh consumed by your home directly, displacing imports at your retail rate (AER 2026 DMO average A$0.34/kWh).
  • Feed-in credit — solar kWh exported to the grid, paid at your retailer’s FIT rate (state-set minimum or higher market offer).

Plug in seven numbers and the calculator returns annual production, annual imports, annual exports, your gross annual bill before solar, your net bill after solar, dollar savings, and percentage bill reduction.

  1. System size (kW) — DC nameplate. CEC marketplace data shows the average Australian residential install in 2025 was 8.6 kW DC (up from 6.6 kW pre-2022).
  2. Peak sun hours/day — Bureau of Meteorology averages: Sydney 4.2, Melbourne 3.8, Brisbane 4.6, Perth 5.0, Adelaide 4.4, Darwin 5.7, Hobart 3.5, Canberra 4.5.
  3. Annual usage (kWh) — AEMC 2024 average: 6,800 kWh for a NEM household, 5,000 kWh in WA, 8,000 kWh in tropical QLD/NT.
  4. Retail rate ($/kWh) — AER 2026 DMO blended: NSW $0.34, VIC $0.27, SA $0.42, QLD $0.30. WA Synergy A1 standard $0.30. Use your actual bill rate if available.
  5. Feed-in credit ($/kWh) — typical market: 4–8c (NSW, QLD, SA), 3.3–6c (VIC after 1 July 2025 reset), 2.5c off-peak / 10c peak (WA DEBS). Origin Solar Boost up to 14c capped.
  6. Self-consumption (%) — 25–35% without battery, 70–85% with battery. Daytime-occupied households trend higher.
  7. Daily supply charge (annual) — typical $1.00–$1.30/day = $365–$475/year. Non-bypassable.

How the math works

annual_kWh_produced  = system_kW × peak_sun_hours × 365 × 0.77
self_consumed        = min(annual_use, annual_prod × self_pct/100)
imports_kWh          = max(0, annual_use - self_consumed)
exports_kWh          = max(0, annual_prod - self_consumed)
gross_bill           = annual_use × retail_rate + supply_charge
import_cost          = imports_kWh × retail_rate
fit_credit           = exports_kWh × fit_rate
net_bill             = max(supply_charge, import_cost - fit_credit + supply_charge)
annual_savings       = gross_bill - net_bill

The 0.77 performance ratio aligns with CEC Solar Accreditation guidelines for Australian conditions — covering inverter losses (3%), DC cable (1–2%), soiling (3–5%, higher in dust-prone WA/NT), thermal derating in 30°C+ ambient (8–12%), and module mismatch (1–2%). AS/NZS 4509 and CEC Design Guideline Section 4 use 0.75–0.80 in standard yield calculations.

Worked example: 6.6 kW in Sydney on AGL Solar Savers

  • System: 6.6 kW DC, 4.2 PSH (Sydney BOM), retail $0.32 (AGL Standing), FIT 6c
  • Annual production: 6.6 × 4.2 × 365 × 0.77 = 7,793 kWh/yr
  • Annual usage: 6,800 kWh, supply charge $1.10/day = $401.50
  • Self-consumption 30% no battery → 2,338 kWh × $0.32 = $748.16
  • Imports: 6,800 − 2,338 = 4,462 × $0.32 = $1,427.84
  • Exports: 7,793 − 2,338 = 5,455 × 6c = $327.30
  • Gross bill: 6,800 × $0.32 + $401.50 = $2,577.50
  • Net bill: max($401.50, $1,427.84 − $327.30 + $401.50) = $1,502.04
  • Annual savings: $1,075 — 42% bill reduction

Worked example: same system with 10 kWh battery

  • Self-consumption 80% → 5,440 kWh × $0.32 = $1,740.80 avoided
  • Imports: 6,800 − 5,440 = 1,360 × $0.32 = $435.20
  • Exports: 7,793 − 5,440 = 2,353 × 6c = $141.18
  • Net bill: max($401.50, $435.20 − $141.18 + $401.50) = $695.52
  • Annual savings: $1,882 — 73% bill reduction

In this usage example the battery adds about A$807/year. Calculate its current program discount using the regulator’s battery-STC calculator, then divide the disclosed net installed cost by that uplift. Warranty, degradation and tariff changes can materially extend simple payback.

State-by-state FIT snapshot (Q1 2026)

StateMinimum FITTypical market FITNotes
Victoria3.3c (1 Jul 2025)3.3–6cESC review pushed minimum down from 4.9c
New South Wales4.9–8c (IPART benchmark)5–12cHigher market plans available (Origin Solar Boost)
Queensland~6c reference4–13.5cErgon regional often higher than south-east
South Australia4.3c4–14cAGL Solar Savings highest market plan
Western Australia2.5c off-peak / 10c peak DEBSSynergy/Horizon onlyTwo-rate TOU-based FIT
Tasmania8.94c8.94c+Aurora regulated FIT, no real market competition
ACT12c (legacy) / market only6–10c new connectionsLegacy 1:1 buyback closed
Northern Territory8.32c (Tier 1)Tier 1 onlyPower and Water regulated

Sources: ESC (VIC), IPART (NSW), QCA (QLD), ESCOSA (SA), Synergy/Horizon (WA), Aurora Energy (TAS), ICRC (ACT), Power and Water (NT). Verified Q1 2026.

STCs, Solar Battery Rebate, and the 2026 incentive stack

The Small-scale Renewable Energy Scheme creates STCs at installation from rated kW, postcode zone and the deeming period. In 2026, a 6.6 kW Zone 3 system creates about 45 STCs using the five-year period. At an illustrative A$35-A$40 assigned value, that is about A$1,575-A$1,800 before fees. Use the solar panel tax credit calculator and confirm the live figure in the Clean Energy Regulator process.

The Cheaper Home Batteries Program adds battery STCs, but the rules changed on 1 May 2026. The factor now changes every six months and tapers by capacity band. Use the installation date and usable capacity in the official calculator rather than applying the launch-period A$/kWh figure.

State stack: VIC Solar Homes interest-free battery loan up to $8,800; NSW Empowering Homes loan; SA Home Battery Scheme grant (closed but private finance partners continue offering 0% loans). These do not affect the calculator output directly but shorten payback meaningfully.

DMO vs Market Offer — choosing your retail rate

The AER Default Market Offer (DMO) is the maximum a retailer can charge unless you’ve opted into a Market Offer plan. In NSW the 2026 DMO is roughly $0.34/kWh residential; in SA it’s $0.42; QLD $0.30. Market Offers are nearly always cheaper than DMO — Energy Made Easy (energymadeeasy.gov.au) ranks Market Offers by total annual cost net of FIT for your AEMO postcode. Picking a retailer 10% below DMO saves 5–8% on your post-solar net bill in most NEM regions.

VIC uses the Victorian Default Offer (VDO) instead, set by the Essential Services Commission; WA’s regulated market means Synergy A1 standard and Horizon are the only options (no shopping around).

Sources

  • Australian Energy Regulator, Default Market Offer 2026–27 Final Decision and Energy Made Easy plan database.
  • Clean Energy Council, 2024 Australian Solar Industry Report and Solar PV Design Guidelines.
  • Essential Services Commission Victoria, Minimum Feed-in Tariff Determination 1 July 2025–30 June 2026.
  • Australian Government, Cheaper Home Batteries Program guidelines (Department of Climate Change, Energy, the Environment and Water).
  • SunWiz, Australian PV Market 2025 Annual Report.
  • Bureau of Meteorology, Australian Solar Energy Map (NSRDB-equivalent).

Frequently asked questions

Does Australia have net metering?
Not in the strict one-to-one sense — Australia uses gross metering with a separate feed-in tariff (FIT). Your import meter records imports at your retail rate; your export meter records exports paid at the FIT rate. The economic effect is similar to a partial net-metering regime where the credit rate (FIT) is roughly 15–25% of the retail rate. State-set FIT minimums vary widely: Victoria mandated 3.3c/kWh from 1 July 2025, New South Wales IPART recommends 4.9–8c, Queensland uses ~6c reference, South Australia minimum 4.3c, Western Australia DEBS pays 2.5c off-peak and 10c peak (15:00–21:00). Retailers usually offer above the minimum to attract customers — Origin, AGL, and Red Energy often pay 6–12c depending on plan.
How much will solar save me on my electricity bill in 2026?
A 6.6 kW Sydney example producing 9,250 kWh/yr at 30% self-consumption saves about A$943 on imports at A$0.34/kWh plus A$389 from exports at A$0.06/kWh, or roughly A$1,330 in year one. The upfront PV support is not a blanket 30% rebate: a 2026 Zone 3 system creates about 45 STCs, whose assigned value must be shown in the quote. Model any battery separately using the current Clean Energy Regulator battery-STC calculator because factors changed on 1 May 2026.
What is the difference between the FIT and the STC rebate?
An STC is an upfront certificate commonly assigned to the retailer for a purchase-price discount; it is not worth A$400-A$500. The clearing-house price is A$40 and open-market or assigned values vary. With the 2026 five-year deeming period, a 6.6 kW Sydney Zone 3 system creates about 45 STCs—roughly A$1,575-A$1,800 at an illustrative A$35-A$40 each before fees. A feed-in tariff is the separate ongoing credit for exported kWh.
Should I take the highest FIT offer or the cheapest retail rate?
Cheapest retail rate, usually. The math: average self-consumption is 30%, so 70% of your generation exports. A 6.6 kW system in Sydney exporting 6,475 kWh × 2c higher FIT = $130/yr extra. Meanwhile imports of 4,600 kWh × 2c higher retail = $92/yr more on imports. The retail rate dominates if you import more than 30% of what you export. If you have a battery (self-consumption 75–85%) the FIT rate matters even less. Energy Made Easy (energymadeeasy.gov.au) is the AER's compare-the-deal site — it ranks plans by total annual cost net of FIT for your usage profile, which is the right metric.
Will the Federal Solar Battery Rebate help my payback maths?
Potentially, but use the current rules. From 1 May 2026 the Cheaper Home Batteries Program changed the STC factor, adjusts it every six months and tapers support above 14 kWh and again above 28 kWh. Run the Clean Energy Regulator battery-STC calculator for the installation date and usable capacity, then compare the disclosed net battery cost with the annual savings uplift. Do not rely on the program's original flat per-kWh examples.

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