Local guide: Australia / English. All amounts are AUD. The rates below are hypothetical, not current retailer offers.
Already have rooftop solar and deciding whether to change electricity plans? Compare the credit for your actual exported electricity with the import and daily supply charges for the same dates. You need daily export records if a higher feed-in tariff has a cap that genuinely resets each day.
A larger advertised solar feed-in tariff does not settle the choice. The same total exports can earn different credits when their daily pattern changes. This guide shows that arithmetic, not a live plan ranking, a new-system payback estimate or a battery recommendation.
What records do you need before comparing the plans?
Energy.gov.au explains that feed-in tariffs pay for excess electricity from small-scale renewable generation, and that plans and amounts vary among retailers. Start with your own plan documents, rather than treating a headline cents-per-kWh figure as a complete offer.
Choose one dated period. Record grid imports in kWh, grid exports by day, the number of charged days and both plans’ applicable rates. Use the same import and export records for both plans. Do not substitute total panel generation or household consumption for metered grid exports.
- Export credit: write down the higher rate, its kWh allowance, the lower rate and any time restrictions.
- Cap rule: confirm whether the allowance resets each day, is averaged across a billing period, or follows another rule. Ask the retailer if the wording is unclear.
- Import and supply: copy the usage charge and daily supply charge, with their units, applicable dates and tax basis.
- Other conditions: check eligibility, fees, discounts, rate-change dates and any existing benefits you would lose.
The daily formula below applies only when the contract confirms a separately resetting daily allowance with no unused allowance carried to another day. A billing-period or averaged allowance needs its own calculation. Do not infer the rule from the word “daily” in an advertisement.
Why can the same total exports reverse the FiT ranking?
Here is a hypothetical two-day example. Plan A pays 10 cents per kWh for the first 10kWh exported each day, then 3 cents per kWh for that day’s excess. Plan B pays a flat 8 cents per kWh. These are invented teaching inputs, not Origin, AGL or another retailer’s terms.
For each day, Plan A’s credit in dollars is: min(daily exports, 10) × 0.10 + max(daily exports − 10, 0) × 0.03. Add those daily credits. Plan B’s credit is total exports × 0.08. Here, “min” selects the smaller value and “max” prevents a negative excess.
| Export record | Plan A: daily cap | Plan B: flat rate |
|---|---|---|
| Day 1: 2kWh | 2 × $0.10 = $0.20 | 2 × $0.08 = $0.16 |
| Day 2: 18kWh | 10 × $0.10 + 8 × $0.03 = $1.24 | 18 × $0.08 = $1.44 |
| Total: 20kWh | $1.44 | $1.60 |
With exports of 2kWh and 18kWh, Plan B earns $0.16 more credit: $1.60 − $1.44. Plan A’s higher headline rate does not compensate for the exports paid at its lower rate.
Now change only the distribution to 10kWh on each day. The total remains 20kWh. Plan A earns $1.00 + $1.00 = $2.00, while Plan B still earns $1.60. Plan A now earns $0.40 more. The preferred FiT reverses without changing total exports.
Both patterns average 10kWh a day. Applying that average to the uneven pattern would wrongly assign all 20kWh to Plan A’s higher tier and report $2.00. That overstates its actual $1.44 credit by $0.56. Spare allowance on the low-export day cannot be moved to the high-export day under this hypothetical contract.
If you have only a bill’s total exports, do not present a daily-capped credit as exact. Request daily records or ask the retailer to calculate the offer using your meter data. An average-based scenario is an assumption, not a reconstruction of the bill.
What happens after import and supply charges are included?
Keep the same two export patterns, but add hypothetical import costs. Over the two days, both plans serve 20kWh of grid imports. Plan A charges 30.5 cents per imported kWh and $1.05 a day for supply. Plan B charges 30 cents per kWh and $1.00 a day.
Before export credits, Plan A costs 20 × $0.305 + 2 × $1.05 = $8.20. Plan B costs 20 × $0.30 + 2 × $1.00 = $8.00. In this simplified model, net cost = import kWh × import rate + days × daily supply charge − export credit.
| Same-period exports | Plan A net cost | Plan B net cost |
|---|---|---|
| 2kWh then 18kWh | $8.20 − $1.44 = $6.76 | $8.00 − $1.60 = $6.40 |
| 10kWh then 10kWh | $8.20 − $2.00 = $6.20 | $8.00 − $1.60 = $6.40 |
For uneven exports, Plan A costs $0.36 more: $6.76 − $6.40. With even exports, Plan A costs $0.20 less: $6.40 − $6.20. Both results include the same imports and charged days, so the daily export pattern still changes the decision.
These totals are not predicted bills or typical household savings. They assume constant single-rate imports and only the listed charges and credits. Do not multiply this two-day illustration into annual savings; use your own records across relevant seasons and rate periods.
How much extra credit must the higher-FiT plan earn?
Compare the credit advantage with the extra non-export cost. For Plan A to have a lower simplified net cost, its credit minus Plan B’s credit must exceed: import kWh × (A import rate − B import rate) + days × (A daily supply − B daily supply).
In the example, that hurdle is 20 × ($0.305 − $0.30) + 2 × ($1.05 − $1.00) = $0.20. The even pattern’s $0.40 extra credit clears it by $0.20. The uneven pattern gives A $0.16 less credit, not an advantage, so A finishes $0.36 behind.
Equality means a tie before excluded items, not a reason to switch. If A’s import and supply costs are lower, the hurdle can be negative; use the signed difference rather than forcing it to zero. Check any other charges or benefits separately before deciding.
For your worksheet, keep unrounded intermediate calculations and round the displayed totals to cents. Check the contract’s actual rounding and settlement rules if reconciling an invoice. If rates change inside the period, split the records at the effective date instead of applying one rate to every day.
When does this simple comparison not fit?
- Your allowance is not settled separately each day. Use the contract’s actual averaging or billing-period method. The daily-cap example cannot resolve ambiguous terms.
- Prices vary by time or demand. Time-of-use import or export rates, controlled-load rates and demand charges require matching interval records and their charging rules, not a single import price.
- Additional items affect the offer. This model excludes extra fees, export network charges, separate tax adjustments, conditional discounts and one-off credits. Check whether any apply to your contract and include them consistently in a full comparison.
- Your usage or system will change. A battery, new appliances or changed daytime occupancy can alter imports and exports. Repricing old records does not predict that new behaviour or establish a new solar system’s return.
Energy Made Easy says the offer and how you use energy affect the savings, and provides a way to compare plans for solar customers. Use the official comparison service where available and your retailer’s written quote to check the full offer. This worksheet is an error check, not a replacement for those terms.
Once you have a realistic electricity amount, carry it into the Australian household budget review. Keep the actual payment dates separate: a lower comparison-period cost does not tell you when cash must leave your account.
Quick decision checklist
- Use the same dated grid import and export records for both plans.
- Confirm the allowance reset rule; obtain daily data before calculating a genuinely daily-capped credit.
- Compare both net costs and the extra-cost hurdle, not just the higher FiT.
- Check eligibility, excluded charges, discount conditions and rate-change dates in the written offer.
- Use a suitable comparison service and review more than a two-day sample before switching.
Sources, scope and editorial note
- Energy.gov.au: Solar feed-in tariff. Supports the purpose of export payments and variation among retailer plans; not the fictional rates or daily-cap rule used here.
- Australian Energy Regulator, Energy Made Easy: Solar plans. Supports comparing solar electricity offers and the importance of energy use and offer terms. Its page is dated 25 October 2023; no state scheme descriptions are relied on here.
Sources checked 17 October 2026. All worked rates and export patterns are hypothetical. This guide was prepared with AI assistance and source checking; it has not received professional financial or legal review. It is educational, not a retailer recommendation or a statement of your contract’s entitlements.
