Solar Battery Savings Calculator Australia 2026: Step-by-Step
Most solar and battery calculators give you an optimistic number without showing their working. This guide does the opposite — it walks you through the calculation step by step using your actual electricity bill data, so you can understand and trust the result.
What You Need Before You Start
From your electricity bill: average daily electricity consumption (kWh/day), electricity import rate (c/kWh), current feed-in tariff rate (c/kWh), average daily solar export (kWh/day). From installer quotes: solar system size and estimated annual generation, battery size and net installed cost after rebates.
Step 1 — Calculate Your Solar-Only Annual Savings
A. Self-consumed solar: Daily self-consumption (kWh) × import rate × 365. Example: 8 kWh × $0.33 × 365 = $963/year
B. Feed-in tariff earnings: Daily export (kWh) × feed-in tariff × 365. Example: 12 kWh × $0.07 × 365 = $307/year
Solar payback: Net system cost ÷ annual saving. Example: $6,000 ÷ $1,270 = 4.7 years
Step 2 — Calculate Battery Annual Savings
Each kWh stored and used at home saves: import rate − feed-in tariff. Example: $0.33 − $0.07 = $0.26 per kWh. At 8 kWh/evening: 8 × $0.26 × 365 = $760/year from the battery alone.
Battery payback: $7,500 ÷ $760 = 9.9 years (conservative — VPP income and rising electricity rates typically reduce real payback to 6–8 years). See our battery savings guide for more detail.
Step 3 — Combined Solar + Battery Payback
Total annual saving = $1,270 + $760 = $2,030/year. Total combined cost = $13,500. Combined payback = 6.7 years. This is typically shorter than calculating each separately due to shared installation costs.
Quick Reference: Payback Periods by State
| State | Import rate | FiT rate | Net system cost | Annual saving | Payback |
|---|---|---|---|---|---|
| SA | 42c | 5c | $13,000 | $2,400 | 5.4 years |
| QLD | 30c | 9c | $12,500 | $1,850 | 6.8 years |
| NSW | 33c | 7c | $13,500 | $2,030 | 6.7 years |
| VIC | 29c | 4c | $13,000 | $1,650 | 7.9 years |
| TAS | 27c | 9c | $14,000 | $1,350 | 10.4 years |
For help sizing your battery, see our solar battery size guide. To understand what the Cheaper Home Batteries Program rebate saves you, see our full rebate guide.
Frequently Asked Questions
How accurate are solar savings calculators?
These calculations are solid estimates based on your bill data. Actual savings depend on how you use electricity, electricity price changes, and system performance.
Do the savings increase over time?
Yes — electricity prices rise over time. Each kWh of solar or battery electricity becomes more valuable as grid prices increase.
Calculations based on 2026 Australian electricity rates and system costs.
