Solar Electricity Bill Calculator Australia
Estimate your solar electricity bill using your own grid usage, solar export and feed-in tariff entered by you, from your own electricity bill.
How this calculator works: Enter the electricity your household imports from the grid, the electricity your solar system exports, your feed-in tariff, your usage rate and your daily supply charge. The calculator estimates your solar electricity bill, or a net credit if your export credit is larger than your charges.
Every figure in the result comes directly from what you type in below.
Enter Your Solar Bill Details
Shown near the dates on your bill. Quarterly bills are usually around 90–92 days.
This is what you bought from the grid, not what your panels produced. Look for "grid usage" or "electricity purchased".
Enter the exact rate on your bill. This calculator does not suggest or assume a rate for you.
The fixed daily charge for your grid connection. It applies to solar households too.
Only the surplus your system sent back to the grid, not your total solar generation.
The exact rate your retailer credits you for exported electricity. Feed-in tariffs vary by retailer and plan, so use your own figure.
Enter as a positive amount. It is subtracted from the bill.
Annualised estimate = bill ÷ billing days × 365. These are estimates, not future bills.
What This Solar Electricity Bill Calculator Does
This calculator is built for Australian households with rooftop solar. Rather than estimating a standard electricity bill, it works through the extra layer solar adds: electricity you still buy from the grid, electricity you send back to the grid, and the credit you receive for that exported electricity. The result is a net estimate either a bill to pay or, in some cases, a net credit.
Every number in the result comes from what you enter. There is no built-in government reference rate, no default market offer figure, and no retailer preset anywhere in this tool. If you haven't entered a rate, the calculator has no rate to fall back on, on purpose, because a solar household's usage rate and feed-in tariff are specific to their own retailer and plan.
How to Use This Calculator
- Find your latest electricity bill and locate the billing period in days.
- Enter the electricity you imported from the grid (not your solar generation) and your usage rate.
- Enter your daily supply charge.
- Enter your solar export in kWh and your feed-in tariff in c/kWh.
- Add controlled load, other charges or discounts if they appear on your bill.
- Press Calculate My Solar Bill to see your estimate, broken down line by line.
Generation, Self-Consumption and Export: Why the Difference Matters
Solar billing confuses people because there are three different quantities involved, and only one of them earns a credit:
- Solar generation: everything your panels produce across the day. It never appears as a line on your bill.
- Solar self-consumption: the portion of that generation you use in your home as it's produced. It reduces what you import from the grid, but it doesn't show up as a credit, because it never reached the grid.
- Solar export: the surplus sent back to the grid. This is the only portion that earns a feed-in tariff credit.
A household that generates a lot of solar but uses most of it during the day will export less and see a smaller credit than a household with the same system that's out at work and exports more. Same panels, same sunshine, different bill because of when the electricity is used.
How to Calculate a Solar Electricity Bill
The supply charge still applies to solar households, because it covers the cost of staying connected to the network, not how much electricity you draw from it. This is why even a household with a large system and strong exports usually still sees a small charge, rather than a bill of exactly zero.
Worked Example
This example uses illustrative, round numbers to show the method, not typical or recommended rates.
| Item | Calculation | Amount |
|---|---|---|
| Grid usage | 500 kWh × 30 c ÷ 100 | $150.00 |
| Supply charge | 30 days × 100 c ÷ 100 | $30.00 |
| Solar export credit | 100 kWh × 8 c ÷ 100 | -$8.00 |
| Net estimated bill | $172.00 |
If that same household's export climbed to 400 kWh at the same 8 c/kWh feed-in tariff, the credit would rise to $32.00, bringing the net estimate down to $148.00. Nothing about the usage rate or supply charge changes only the size of the export changes the outcome.
Understanding Your Feed-in Tariff
A feed-in tariff is set by your retailer, not by the government, and it can vary significantly between retailers and between plans from the same retailer. It's common for a feed-in tariff to be considerably lower than your usage rate, which is one reason self-consumption (using solar electricity in your own home) is generally worth more to a household than exporting it. Always use the feed-in tariff shown on your own bill or plan documents rather than a figure you've seen mentioned generally, since this calculator won't substitute one for you.
Why the Timing of Your Usage Matters With Solar
Two households with identical solar systems can end up with different bills purely based on when they use electricity. A household that runs the dishwasher, washing machine or pool pump during the middle of the day, when solar generation is highest, uses more of its own solar directly and exports less. A household that's out during the day and uses most of its electricity in the evening exports more solar during the day but then buys more from the grid at night, when panels aren't producing.
Neither pattern is automatically better. It depends on the relationship between your usage rate and your feed-in tariff: if your usage rate is much higher than your feed-in tariff, using solar directly is generally worth more to your bill than exporting it and buying it back later.
Solar and Controlled Load Together
Some solar households also have a controlled load, often used for hot water, on a separate circuit and rate. Controlled load usage doesn't affect your solar export directly, but it's billed on its own line, so it's included as an optional field in this calculator rather than folded into your general usage.
Common Solar Billing Myths
- "Solar means no more bills." Not usually. The supply charge and any grid usage outside solar hours generally still apply.
- "My feed-in tariff is the same as everyone else's." It isn't. Feed-in tariffs are set by retailers and vary by plan.
- "My whole generation counts as a credit." Only the exported portion counts. Self-consumption reduces your import but isn't credited separately.
- "A bigger system always means a bigger credit." Only if the extra generation is actually exported rather than used, or wasted when the household isn't home to use it.
More Electricity Calculators on This Site
If you'd like to check how a specific appliance affects your solar household's usage, the appliance running cost calculator breaks down daily, weekly and annual running costs from an appliance's wattage. If you're in Victoria, the electricity cost calculator for Victoria covers the state's own pricing framework in more detail. For the underlying method behind any of these tools, see how to calculate electricity cost, or use the general electricity cost calculator if your household doesn't have solar.
Frequently Asked Questions
What is a solar electricity bill calculator?
A solar electricity bill calculator estimates your electricity bill when you have solar panels, using the electricity you import from the grid, the electricity you export, your feed-in tariff and your daily supply charge. This calculator uses only the rates you enter, not any assumed or government rate.
How do I calculate my solar electricity bill?
Multiply grid electricity imported by your usage rate, add your daily supply charge multiplied by the billing days, then subtract your solar export credit, which is exported kWh multiplied by your feed-in tariff. All rates should come from your own electricity bill or plan.
What is the difference between solar generation, self-consumption and export?
Solar generation is everything your panels produce. Self-consumption is the portion you use as it is generated, which does not appear as a bill line. Export is the surplus sent back to the grid, and only export earns a feed-in tariff credit.
What is a feed-in tariff?
A feed-in tariff is the rate, in cents per kWh, that your retailer pays or credits you for solar electricity you export to the grid. It is set by your retailer and plan, so enter the exact figure from your bill or contract.
Will solar eliminate my electricity bill completely?
Not necessarily. Most solar households still pay a daily supply charge and still buy some electricity from the grid, particularly at night or during high-use periods. Solar can reduce a bill significantly, but a zero bill is not guaranteed.
Does this calculator use government or retailer default electricity rates?
No. This calculator does not use, assume or auto-fill any government reference rate, default market offer, Victorian Default Offer, or retailer preset rate. Every rate used in the result is the one you type in yourself.
Can I calculate a solar bill without solar generation figures?
Yes. This calculator only needs the electricity you import from the grid and the electricity you export, both shown on your electricity bill. You do not need your solar system's total generation figure to estimate the bill.
Why is my solar credit smaller than I expected?
The credit is based only on exported electricity, not on everything your panels generate. Electricity you use yourself as it is produced, known as self-consumption, does not earn a feed-in credit because it never reaches the grid.
Can a solar bill result in a credit instead of a charge?
Yes, if your solar export credit is larger than your usage and supply charges combined, the result can be a net credit. How that credit is applied, whether it carries forward or is paid out, depends on your retailer.
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