Work out what solar actually costs
Solar Finance & Repayment Calculator
See your real monthly cost with rebates and certificates included.
Borrowing $5,800 over 7 years at 0%
Monthly repayment
$69
Monthly saving
$128
Ahead each month
$59
The expected saving covers the repayment, so the system pays its own way from the first month. Total interest: $0 · total repaid: $5,800 · simple payback on the price: about 3.8 years.
| Term | Monthly | Total interest | vs saving |
|---|---|---|---|
| 3 years | $161 | $0 | −$33 / month |
| 5 years | $97 | $0 | +$31 / month |
| 7 years | $69 | $0 | +$59 / month |
| 10 years | $48 | $0 | +$79 / month |
Estimates, not a credit offer. Fees, comparison rates and eligibility depend on the lender. Savings depend on your usage and tariff.
How rebates and certificates cut your upfront cost
Federal and state rebates are designed to lower the barrier to solar investment. The Small-scale Technology Certificates scheme is the main federal incentive and applies to every solar system under 100 kW.
Your system's kilowatt capacity is multiplied by your postcode's solar resource zone, the five-year deeming period, and the current STC price of $38. This figure is converted to an immediate rebate you see on your installation invoice—you don't claim it later. For a 6 kW system in a typical Australian suburb with a zone multiplier of 1.5, you'd receive roughly $1,700–$2,100 upfront.
The Cheaper Home Batteries Program (from 1 May 2026) works similarly for storage. A 10 kWh battery qualifies for approximately $2,520 under the first tier ($252/kWh for the first 14 kWh), bringing a $12,000–$15,000 battery closer to $10,000 net.
State schemes vary by location. New South Wales, Victoria and Queensland administer their own rebates—some are grants, others interest-free loans. Your postcode determines which schemes apply. Solar Advice can identify every rebate you qualify for during your site assessment.
Check your zone multiplier and STC amount
Enter your postcode on the Clean Energy Regulator website to see your solar resource zone and calculate your STC rebate before you get a quote.
Confirm state rebate eligibility
Visit your state energy agency (NSW: Energy NSW; VIC: Consumer Energy Water; QLD: Energy Queensland) to see current cashback, loan or battery schemes available in your postcode.
Ask your installer to itemise rebates on the quote
A transparent quote shows system cost, then STC rebate and any state rebate separately, so you see your net price clearly.
Ways to pay for solar: cash, loan or lease
Most Australian homeowners finance solar through a personal or home equity loan, which spreads the cost over three to ten years and lets you claim the full benefit of lower electricity bills from month one.
Paying cash upfront avoids interest and means you own the system outright—useful if you plan to stay in your home for ten-plus years. However, you lose the chance to reinvest savings elsewhere. A $15,000 system paid in cash removes that capital from other investments; a loan at 6% costs roughly $290 per month over five years but may be worth it if your typical annual return on savings is higher.
Some solar retailers and banks offer 'solar loans' with fixed rates and terms matched to system life (usually 5–10 years). Pre-approval through your lender before you contact Solar Advice speeds up the process. Always ensure your loan term is shorter than the system's warrantee (usually 25 years for panels) so you own it debt-free well before replacement is likely.
Lease or power-purchase agreements (PPAs) are less common in Australia but do exist. You pay a monthly fee to use the system but do not own it. Rebates (STCs and state schemes) typically go to the lessor, not you—ask about this explicitly if a lease is offered.
Personal loan
Unsecured borrowing at a fixed or variable rate. No collateral required, but rates are typically higher than home loans. Term: 3–10 years. Easiest if you have good credit and stable income.
Home equity loan or line of credit
Borrowed against your home's equity. Rates are lower than personal loans because the debt is secured. You must own your home. Term: flexible, often 10–20 years.
Cash payment
No interest, you own the system outright from day one. Suitable if you have savings and plan to stay in your home long term. Miss the opportunity to reinvest savings.
Understanding monthly repayments and payback time
Your monthly repayment depends on the loan amount, interest rate, term and any fees. A typical example: a $12,000 system after rebates, financed at 6% over five years, costs roughly $230 per month.
Most Australian homes using 15–20 kWh per day save $150–$300 per month on electricity. If your loan payment is $230 and your saving is $250, you're ahead by $20 after month one—and after five years, you own a system that generates free power for another 20+ years.
Payback time is when cumulative electricity savings equal your net system cost. For a $12,000 system with $250/month savings, payback is roughly 48 months (four years). After that, every kilowatt-hour is profit. A longer loan term (ten years instead of five) lowers your monthly cost but extends payback because interest compounds; a five-year term costs more monthly but means you own free power sooner.
To calculate your own payback: divide your net system cost by your monthly bill saving, then multiply by the loan term. Ask Solar Advice for your system's estimated annual generation in kilowatt-hours; multiply by your retailer's per-kWh rate to estimate monthly saving. Then compare loan repayment to saving to see whether you break even or come out ahead.
Gather your electricity bill
Note your annual usage (kWh) and cost (AUD). A typical home uses 12–20 kWh daily; multiply daily use by 365 and your retailer's rate to see annual cost.
Get a system quote from Solar Advice
Ask for estimated annual generation (kWh) for your proposed system size. Multiply by your retailer's rate to see annual bill saving.
Divide annual saving by 12 for monthly figure
Compare your monthly loan repayment to monthly saving. If saving exceeds repayment, you are building equity from day one.
Calculate payback in years
Divide net system cost (after rebates) by monthly saving. A $10,000 system with $200/month saving pays back in 50 months, or just over four years.
How much are monthly repayments on a solar system?
Is it better to pay cash or finance solar?
Are interest-free solar plans really free?
How do Small-scale Technology Certificates reduce the cost of solar?
What is the Cheaper Home Batteries scheme and how much does it discount?
Can I get a loan to spread solar costs over time?
How much does a typical 6 kW solar system cost installed?
Are there state-based solar rebates I should know about?
What if I add a battery to an existing solar system?
How do I compare monthly repayments across different loan terms?
Get a quote and see your rebates upfront.
Tell us your postcode and usage, and we'll calculate your system cost with STCs and state rebates included.