Solar Electricity Bill Savings Calculator (Australia)
See exactly how much your monthly power bill drops after going solar in Australia. Free calculator with 2026 AER DMO rates, state feed-in tariffs, STC rebate and Cheaper Home Batteries built in.
Solar Electricity Bill Savings Calculator
How the math works
How this calculator works
The Solar Electricity Bill Savings Calculator estimates the immediate monthly bill reduction when a CEC-accredited residential PV system replaces grid imports. Side-by-side comparison: today’s bill vs. tomorrow’s bill, in AUD per month, using the AER Default Market Offer (DMO) for 2026 and your state’s typical feed-in tariff.
Eight inputs, four outputs (monthly production, new bill, monthly saved, annual saved):
- Current monthly bill — quarterly bill ÷ 3. Aussie default A$230/mo = A$690/quarter (NSW/VIC average).
- Monthly usage (kWh) — quarterly kWh ÷ 3. Australian average is 19 kWh/day (570 kWh/month) per AER 2024 retail data.
- System size (kW) — 6.6 kW is the median residential install per SunWiz 2025. Use the solar panel estimate calculator for your roof.
- Peak sun hours/day — BoM Daily Global Solar Exposure averages: Darwin 5.6, Brisbane 5.0, Perth 5.4, Adelaide 4.8, Sydney 4.5, Melbourne 4.2, Hobart 3.9.
- Electricity rate (A$/kWh) — your import rate. Default A$0.34/kWh = AER DMO 2026 single-rate weighted average.
- Feed-in tariff (A$/kWh) — your retailer’s export rate. Default A$0.06/kWh = market median 2026.
- Self-consumption (%) — fraction of solar used directly. Default 35% (no battery, average AU home with daytime occupancy).
- Daily supply charge (monthly) — A$1.20/day × 30.4 = A$36/mo default for NSW/VIC.
How the math works
monthly_kWh_produced = system_kW × peak_sun_hours × 30.4 × 0.77
self_consumed_kWh = min(monthly_use_kWh, monthly_kWh_produced × self_pct/100)
exported_kWh = monthly_kWh_produced - self_consumed_kWh
imported_kWh = monthly_use_kWh - self_consumed_kWh
import_cost = imported_kWh × import_rate
export_credit = exported_kWh × FiT
new_bill = max(supply, import_cost - export_credit + supply)
monthly_savings = current_bill - new_billThe 0.77 system performance ratio aligns with CEC Design Guideline assumptions and AS/NZS 5033 system-loss methodology (inverter, wiring, soiling — exacerbated by Australian dust events — and high-temperature derating, which is significant in QLD/NT summers).
Worked example: 6.6 kW system in Sydney
- System: 6.6 kW DC, 4.5 PSH (Sydney BoM annual average)
- Monthly production: 6.6 × 4.5 × 30.4 × 0.77 = 695 kWh/mo
- Use: 570 kWh/mo (19 kWh/day average)
- Rate: A$0.34/kWh (Endeavour DMO 2026)
- 35% self-consumption (no battery, daytime occupancy)
- Self-consumed: min(570, 695 × 0.35) = 243 kWh, offsetting A$83/mo
- Exported: 695 - 243 = 452 kWh × A$0.06 = A$27 credit
- Imported: 570 - 243 = 327 kWh × A$0.34 = A$111 cost
- Plus A$36 supply charge
- New bill: A$111 - A$27 + A$36 = A$120/month
- Old bill: 570 × A$0.34 + A$36 = A$230/month
- Monthly savings: A$110/month, A$1,320/year (48% reduction)
Add a 10 kWh battery (Cheaper Home Batteries rebate brings net cost to A$8,500 installed) and self-consumption climbs to 80%. New bill drops to A$50/month, annual savings A$2,160. Combined battery+system payback ~7 years.
Per-state retail rates and feed-in tariffs (Q1 2026)
AER DMO 2026 import rates and median 2026 fixed feed-in tariffs:
| State / network | Import (A$/kWh) | FiT range (A$/kWh) | Daily supply | Notes |
|---|---|---|---|---|
| NSW Endeavour | 0.32-0.36 | 5.0-12.0 | A$1.10-1.30 | Powershop SunBoost 12c capped 7 kWh/day |
| NSW Essential | 0.34-0.40 | 5.0-9.0 | A$1.20-1.50 | Regional surcharges apply |
| NSW Ausgrid | 0.31-0.34 | 5.0-12.0 | A$1.05-1.25 | Octopus AU 12c flat |
| VIC AusNet/Powercor | 0.28-0.34 | 4.9-7.0 | A$1.10-1.30 | VIC minimum FiT 4.9c (Essential Services Commission) |
| VIC Citipower/Jemena | 0.27-0.33 | 4.9-7.0 | A$1.10-1.30 | VEU EnergySaver scheme rebates |
| QLD Energex (SEQ) | 0.30-0.35 | 6.0-12.0 | A$1.00-1.20 | AGL Solar Savers QLD 8c flat |
| QLD Ergon (regional) | 0.31-0.36 | 8.0-13.5 | A$1.10-1.30 | Ergon regulated 13.441c FiT 2026 |
| SA SAPN | 0.39-0.46 | 4.0-12.0 | A$1.00-1.20 | Highest rates in NEM |
| WA Synergy | 0.30-0.32 | 2.25-10.0 | A$1.10 | DEBS scheme (Distributed Energy Buyback) |
| TAS Aurora | 0.27-0.30 | 8.94 (regulated) | A$1.10 | Tasman Renewable Energy Tariff |
| ACT ActewAGL | 0.26-0.29 | 7.0-12.0 | A$0.90-1.10 | Lowest rates in NEM |
| NT PWC | 0.27-0.29 | 8.30 (regulated) | A$0.85-0.95 | NT Battery Booster grants up to A$12k |
Cheaper Home Batteries Program & state battery schemes (2026)
The federal Cheaper Home Batteries Program (announced 25 March 2025, in force 1 July 2025) cuts 30% off the upfront cost of battery storage paired with solar. Implemented as STCs (Small-scale Technology Certificates) on top of the existing solar STC scheme, with declining rebate values 2025-2030:
- 2025-2026: ~A$370/kWh net rebate (30% deemed)
- 2027: ~A$310/kWh
- 2028-2030: declining to A$240/kWh
Batteries must be CEC-listed and connected to an AS/NZS 4777.2-compliant inverter. Maximum 50 kWh per household. Off-grid installs are eligible (rare exception in Aussie battery rebate history).
Active state-level battery schemes 2026:
- VIC Solar Battery — interest-free loan up to A$8,800 for systems ≤14 kWh, melb metro and regional VIC
- ACT Sustainable Household Scheme — zero-interest loan up to A$15,000 for solar + battery + EV charger combo
- QLD Battery Booster — A$3,000 rebate for income-tested households + 4-year zero-interest loan up to A$10,000
- SA Home Battery — closed November 2022; replaced by Virtual Power Plant rebate scheme via SAPN
- NT Battery Booster — A$12,000 grant for off-grid/grid-connected battery systems in remote communities
- WA Distributed Energy Buyback Scheme (DEBS) — TOU FiT 10c peak (3-9pm), 2.25c off-peak; effectively a battery monetisation tool
Solar STC rebate (still active for the panels themselves)
Separate from the new battery rebate, the original Small-scale Renewable Energy Scheme (SRES) STC rebate continues for PV. Value falls year-on-year:
- 2025: A$2,400-A$3,200 off a 6.6 kW system (Zone 3 NSW/VIC)
- 2026: A$2,100-A$2,800
- 2027: A$1,800-A$2,400
- Phase-out 2030: A$0
Calculator default rates already net this rebate out of typical installed prices in our companion cost calculator. Most CEC accredited installers quote with STC already deducted.
Sources
- Australian Energy Regulator (AER) — Default Market Offer (DMO 7) 2026 (aer.gov.au)
- Clean Energy Council (CEC) — Solar PV Design Guidelines, Battery Installation Guidelines, Approved Products List (cleanenergycouncil.org.au)
- Clean Energy Regulator — Cheaper Home Batteries Program implementation page (cer.gov.au)
- Bureau of Meteorology (BoM) — Daily Global Solar Exposure climate data (bom.gov.au/climate)
- SunWiz — 2025 Australian PV Market Insights Report
- Energy Made Easy — federal retail comparison site (energymadeeasy.gov.au)
- Essential Services Commission VIC — minimum feed-in tariff 2026
For more detail see our 25-year solar panel savings calculator, solar payback period calculator, and cost of solar panels calculator.
For questions about this tool: contact@solarcalculatorhq.com