AUSTRALIA · SOLAR & BATTERY CALCULATOR
Estimate the annual value of solar self-consumption and export credits, or calculate a simple battery payback using your own electricity tariffs, feed-in tariff and battery inputs.
HomeBillLab calculator
Estimate solar value and simple battery payback
Use your own electricity rates, feed-in tariff and battery inputs. No national-average tariff or hidden battery saving is inserted.
Why subtract the feed-in tariff when charging from solar?
If excess solar would otherwise have been exported for a bill credit, storing it has an opportunity cost. The calculator compares the later grid purchase avoided with the export credit forgone, while also allowing for round-trip losses.
Why can a battery have no positive simple payback?
If the value of electricity avoided is not high enough to cover charging losses and the electricity or export value given up, the calculated annual net value can be zero or negative. In that case the calculator does not show a positive simple-payback period.
Does the battery estimate include the Australian Government battery discount?
No fixed discount is built in. If you are eligible for a government or state program, enter your expected installed cost after the discount shown in your quote.
Privacy: calculations run in your browser. The numbers you enter are not submitted to HomeBillLab.
How the solar value calculation works
Solar electricity can be used in the property, exported to the grid, used to charge a battery or curtailed where an export limit applies. For a simple annual value estimate, HomeBillLab separates self-consumed solar from exported solar.
(self-consumed kWh × import tariff avoided) + (exported kWh × feed-in tariff).
This does not estimate solar-system purchase payback. It values the electricity generated using the tariff inputs you provide.
How the battery simple-payback calculation works
Storing excess solar
The calculator estimates how much charged energy is delivered after round-trip losses, values the grid electricity that delivery avoids, and subtracts the feed-in tariff that the original solar energy could otherwise have earned.
Off-peak grid charging
For tariff arbitrage, the calculator values the higher-rate grid electricity avoided after battery losses and subtracts the lower-rate electricity purchased to charge the battery.
Simple payback
Installed battery cost ÷ estimated net annual battery value. If the annual value is zero or negative, no positive simple payback is shown.
Use net installed cost
Enter the amount you expect to pay after any eligible battery discount, rebate or installer incentive. HomeBillLab does not hard-code a universal rebate amount.
Why self-consumption and battery timing matter
Australian Government guidance explains that self-consumed solar reduces electricity bought from the retailer, while exported solar may earn a feed-in tariff. A battery can increase self-consumption, shift energy into higher-price periods and reduce some peak demand, but the upfront battery cost means it does not make financial sense for every household.
What this calculator does not predict
Battery degradation
Usable capacity and efficiency can change over time. This calculator keeps the entered daily energy and efficiency constant for a simple comparison.
Future tariff changes
Import rates, feed-in tariffs and time-of-use periods can change. The calculator uses the rates you enter today and does not forecast future prices.
VPP and demand-charge value
Virtual power plant payments, demand-charge reductions and special export tariffs can add or subtract value, but are not included in the simple-payback result.
Backup and resilience value
Backup power can be important to a household even when it does not shorten financial payback. That non-bill value is not assigned a dollar figure here.
Australian battery discounts and programs
As of this page’s review date, the Australian Government’s Cheaper Home Batteries Program supports eligible small-scale battery installations. Program rules, eligibility and discount values can change, so use the current net installed cost from a quote rather than assuming a fixed percentage inside the calculator.
Related Australian energy guides
Use these guides to check assumptions, follow worked examples and compare common household scenarios.
Guide
Solar Battery Payback in Australia: Is a Home Battery Worth It?
Estimate home-battery payback from net installed cost, usable energy, efficiency, retail tariffs, feed-in credits and realistic daily cycling.
Guide
Solar Self-Consumption Explained for Australian Homes
Learn how solar self-consumption works, calculate your ratio and compare the value of using rooftop solar at home with exporting it.
Guide
What Size Solar Battery Do I Need in Australia?
Use household interval data, surplus solar, later electricity use, usable capacity and power output to compare solar battery sizes in Australia.
Official Australian references
- energy.gov.au — How solar pays for itself and batteries reduce bills
- energy.gov.au — Electricity pricing plans and tariffs
- energy.gov.au — Batteries
- energy.gov.au — Cheaper Home Batteries Program
Reviewed: 21 August 2026.
Solar and battery savings calculator FAQs
Why is self-consumed solar usually worth more than exported solar?
Self-consumption can avoid buying a kWh from the grid at your retail usage rate. Exported solar normally earns only the feed-in tariff that applies to your plan, which may be lower.
Should I enter battery cost before or after rebates?
For simple payback, enter the net installed cost you expect to pay after any eligible discount, rebate or installer incentive. Check current program rules rather than assuming a fixed national amount.
What round-trip efficiency should I use?
Use a model-specific figure from product documentation or a reliable system specification where available. The calculator does not insert a default efficiency because products and operating conditions differ.
Does a shorter simple payback mean a battery is definitely the best option?
No. A simple payback is only one comparison measure. Warranty, degradation, backup needs, financing, tariff changes, VPP terms, installation constraints and household usage patterns also matter.