Solar Self-Consumption Calculator
Estimate how much of your solar generation you use directly at home versus export, and the resulting bill savings.
Your results
Calculation breakdown
- Self-use savings
- Savings = generation × self-consumption share × usage rate
- Export credit
- Credit = generation × (1 − self-consumption share) × feed-in rate
Worked example
Generating 20 kWh a day with 40% self-consumed at 30c/kWh usage rate and 5c/kWh feed-in on the rest gives about $2.40 self-use savings plus $0.60 export credit, or roughly $1,095 a year in total.
Assumptions
- Self-consumption share depends on when appliances run relative to solar generation; adding a battery increases it.
- Excludes the solar system's own capital and maintenance cost, covered by other payback calculators.
- Assumes a flat usage rate rather than a time-of-use tariff.
How this calculator works
Enter your daily solar generation, the share you self-consume, your electricity usage rate and your feed-in tariff to estimate the savings from self-consumed solar plus the credit from exported solar. Increasing self-consumption, for example by running appliances during the day, generally increases savings because usage rates are higher than feed-in rates.
Frequently asked questions
What is a typical self-consumption rate?
Many Australian households without a battery self-consume roughly 30–50% of solar generation, with the rest exported to the grid.
How can I increase self-consumption?
Running high-draw appliances like pool pumps, dishwashers and washing machines during daylight hours increases the share of solar you use directly.
Does adding a battery change this calculation?
Yes, a battery stores excess solar for evening use, increasing effective self-consumption; you can model this by increasing the self-consumption share input.
Actual prices, usage, efficiency and savings vary by provider, equipment, location and behaviour.