Solar On Your Rental: When It Pays For Australian Landlords

Should you put solar on a rental? The short answer

For Australian landlords, adding solar to a rental property makes sense when:

1. The extra rent or bill savings can realistically repay the system in about 6–10 years.
2. You avoid expensive finance (high‑rate personal loans, BNPL, vendor finance).
3. The roof and wiring can support 15–25 years of life from the system.
4. The property itself still passes basic cashflow and risk tests after 2027’s negative gearing changes.

This guide shows you, in numbers, how to check that this week.

Decision rule in one paragraph: Solar on a rental is usually worth it if a $5,000–$8,000 system can be funded at home‑loan rates, deliver at least $800–$1,200 per year of real benefit to you (through higher rent and/or lower bills), and your property still survives a 3% rate rise and three months’ vacancy on a pre‑tax basis.

Start with realistic costs and savings before deciding on solar for your rental.

1. Start with the investment property basics

Before you worry about panels, make sure the property itself stacks up.

Post‑reform, most new established residential investments should be judged on pre‑tax cashflow, with minimal or no wage‑offset negative gearing benefit (see facts 3, 5, 6, 7, 10, 17, 19, 20 in the knowledge hub).

A property is only a good candidate for solar if, without solar, it:

• Survives a 3% interest rate rise.
• Copes with flat rents for a few years.
• Survives three months’ vacancy per year on your cash buffer.

Those are the same stress‑test rules we use for new investors and refinancers.

If your property is already borderline, you may be better off revisiting your whole strategy first. Walk through that process in Stuck With An Underperforming Investment Property? Decide This Week.

Quick property readiness check

Only move ahead to solar if you can honestly tick most of these:

• Cash buffer: You hold at least 3–6 months of combined household and property expenses in cash or offset.
• Loan stress test: At an interest rate 3% higher than today, combined home + investment repayments stay ≤35% of after‑tax income.
• Strategy horizon: You expect to hold this property for at least 7–10 years.
• Maintenance backlog: No major roof or switchboard issues are looming, or you’ve budgeted for them.

If two or more are a “no”, pause the solar conversation and tighten your base first.

2. How landlords actually benefit from solar

Unlike an owner‑occupier, you don’t live under the panels. You only benefit if money finds its way back to you:

1. Higher rent for a more efficient home (tenant pays their own bill, but pays a premium rent).
2. “Bills included” rent where you keep the bill in your name and keep most of the solar savings.
3. Lower landlord-paid outgoings (e.g. if you pay for common area power in small blocks).
4. Indirect benefits: lower vacancy, better tenants, potentially slightly better valuation over time (covered in your sibling article on valuers).

Option A: Higher rent, tenant keeps the bill

You install solar, tenant keeps the electricity account and enjoys lower bills. You aim to charge higher rent.

Typical levers:

• Rent uplift: Often $10–$30 per week is realistic in metro and regional areas if marketed properly and the system size fits household usage.
• Vacancy: A more attractive listing may rent faster and reduce gaps.

Example – simple rent uplift model

• System cost: $6,000 (6.6 kW on a standard suburban home).
• Extra rent achieved: $20/week = $1,040/year.
• No extra ongoing costs other than minor maintenance.

Simple payback: $6,000 ÷ $1,040 ≈ 5.8 years.

If you’re holding for at least 10 years and the system is decent quality, this can be attractive.

The catch: you must realistically be able to achieve and sustain that rent premium in your local market.

Option B: Bills included (you control the bill)

Here, you:

• Keep the power account in the landlord/entity name.
• Include “electricity included up to X kWh per quarter” in the lease.
• Set rent higher to cover the average bill minus expected solar savings.

This structure is more complex but can let you capture more of the solar benefit. The traps, and the way to stress‑test it, are covered in detail in your companion piece Can You Charge Tenants More for ‘Bills Included’ When You Install Solar?.

A key principle from that article: always compare annual solar finance costs to conservative bill savings and planned rent uplift, stress‑testing with at least 20% lower savings and 3% higher interest rates.

We’ll run those numbers in Section 5.

Option C: Common power or small blocks

If you pay for common area power (stairwells, garages, security), solar can directly cut a bill you’re already paying.

This is often overlooked but simpler than trying to capture rent uplift. Whichever benefit pathway applies to you, the core question is:

"How many dollars a year end up in my pocket, after stress‑testing?"

3. Indicative numbers: costs, savings and payback for rentals

Solar quotes vary wildly. The numbers below are illustrative only but grounded in typical Australian metro pricing (no batteries, STCs included).

Typical system sizes and costs

Tip: If tenants are a typical family with daytime usage, 6.6–8 kW is usually the most cost‑effective balance.

Realistic annual savings for tenants

For a standard 6.6–8 kW system on a family home:

• Typical gross bill reduction for occupiers is often touted as $1,200–$1,800 per year.
• As a landlord, you should work off conservative numbers because you don’t control behaviour:
  • Low case: $600/year benefit to tenant.
  • Base case: $1,000/year.
  • Optimistic (don’t bank on it): $1,400+/year.

Your ability to capture a share of that depends on the rent/billing structure.

Simple gross payback (ignoring finance)

*"Benefit to you" could be higher rent, lower outgoings, or a bills‑included margin.

As a rule of thumb for rentals:

• < 7‑year simple payback = worth serious consideration.
• 7–10 years = depends on your holding period and risk appetite.
• > 10 years = usually only worth it if you have other reasons (green branding, upcoming selling angle, or very cheap finance).

4. How you finance solar on an investment property

How you pay has as much impact as the solar itself. A good system on bad finance can turn a decent idea into a drag on cashflow.

You’ve got four broad choices:

1. Cash.
2. Home loan / investment loan top‑up or split (secured, lower rate).
3. Separate personal/green loan.
4. BNPL / vendor finance from the solar provider.

We’ve broken out the traps and comparisons in Personal loans vs BNPL vs vendor finance for solar: real costs, but let’s focus on landlord‑specific numbers.

Comparison: cash vs loan options (illustrative)

Assume: $6,000 system, 10‑year effective life for payback purposes (the system may last 20+ years), comparison rates are indicative only.

*Interest may be deductible if the borrowing is genuinely and solely for income‑producing purposes. Always get personal tax advice.

The safest pattern for most investors is:

• If using equity, create a separate, clearly labelled loan split for solar, matching term to expected payback (7–10 years).
• Keep any personal solar or renovation costs separately split to protect tax tracing, consistent with our broader guidance on loan quarantining.

If you’re considering using equity, read Using Home Equity for Solar: How Much You Can Really Borrow for worked examples and lender rules, then come back to this article to test payback.

Worked example: investment loan split vs personal loan

• System cost: $6,000.
• Option 1: Investment loan split at 6.5% over 10 years: repayment ≈ $820/year.
• Option 2: Green/personal loan at 9.5% over 7 years: repayment ≈ $1,140/year.
• Expected benefit to you (after rent uplift / bills structure): $1,000/year.

Option 1 outcome (loan split):

• Net cashflow: $1,000 benefit – $820 repayment = +$180/year.
• Stress test with 3% rate rise (to 9.5%): repayment ≈ $1,020/year ⇒ modest –$20/year loss, manageable if the property overall passes your 3% buffer test.

Option 2 outcome (personal loan):

• Net cashflow: $1,000 – $1,140 = –$140/year loss from day one.
• With rate rise or lower benefit, loss widens.

This is why the finance structure is critical.