Australia 2025 • Solar feed-in tariff • ROI • Payback
Solar Savings Calculator (House vs Unit)
주택 vs 아파트 솔라 절감 효과 계산 — solar feed-in tariff, ROI, payback
TL;DR Summary (5 points)
- House roofs usually allow larger systems, higher self-consumption and faster payback (years).
- Units/apartments need strata approval and roof access; systems are smaller, so ROI depends more on feed-in tariff (FiT) and daytime usage.
- Key drivers of savings: self-consumption %, grid tariff (¢/kWh), FiT (¢/kWh), and upfront cost per kW.
- Simple payback = upfront cost ÷ annual benefit; ROI = annual benefit ÷ upfront cost.
- Use the calculators below to compare your house vs unit numbers for Australia 2025.
Concept Overview — why this matters in Australia
- Electricity rates and FiTs vary by retailer/state. A higher usage tariff and good self-consumption usually mean faster payback.
- STC incentives reduce upfront cost, but you still want the best $/kW and reliable installers.
- Apartments may use embedded networks or require common-property approvals, affecting feasibility and costs.
- Real-world outcomes depend on daytime load (e.g., WFH, EV charging, heat pump) and shading/roof orientation.
Tip: Model with your own tariff plan and realistic self-consumption (often 30–60% without a battery).
Solar Savings Calculator — Australia 2025
Enter your numbers. The tool compares House and Unit side-by-side using the same method.
House
Annual generation: — kWh
Bill savings (self-use): $— • FiT income: $—
Annual benefit (net): $—
Upfront cost: $—
ROI (year 1): —% • Payback: — yrs
Unit / Apartment
Annual generation: — kWh
Bill savings (self-use): $— • FiT income: $—
Annual benefit (net): $—
Upfront cost: $—
ROI (year 1): —% • Payback: — yrs
Comparison Table — House vs Unit (outputs)
| Feature | House | Unit / Apartment |
|---|---|---|
| Upfront cost | — | — |
| Annual generation | — | — |
| Self-use savings | — | — |
| Feed-in income | — | — |
| Annual benefit (net) | — | — |
| ROI (year 1) | — | — |
| Simple payback | — | — |
| Strengths | Room for larger arrays; higher self-use potential; easier meter changes | Smaller arrays suit low loads; high self-use if WFH; less roof shading in some blocks |
| Limitations | Tree shading; older switchboards may need upgrades | Strata approvals, roof access limits, embedded network rules, shared costs |
| Best For | Families, EV owners, heat-pump households, daytime usage | Owner-occupiers with high daytime use, supportive strata, good roof aspect |
Who Each Option is Best For (decision criteria)
- House You can install ≥5 kW, have weekday daytime load, and want faster payback from self-consumption.
- Unit You have strata approval, realistic system size (e.g., 2–4 kW), and a retailer plan with fair feed-in tariff.
- Either You can shift loads (washing, dishwasher, EV) to daytime to lift ROI.
Step-by-Step: How to choose in 2025
- Check feasibility: roof space/orientation, shading, meter/switchboard, strata (for units).
- Size your system: match to annual usage and daytime profile. Avoid gross oversizing if FiT is low.
- Get quotes: at least 3 CEC-accredited installers. Compare $ per kW, warranties, workmanship.
- Model numbers: use the calculator with your grid tariff, FiT, and realistic self-consumption.
- Select plan: choose a retailer plan with transparent solar feed-in tariff and fair daily supply charge.
- Install & connect: final electrical works, meter change if required, approval to connect.
- Optimise: shift loads to solar hours; monitor app; review ROI and payback annually.
Costs, Fees & Tax (Australia 2025)
- Upfront: panels + inverter + mounting + labour (often shown as $ per kW after STC incentive).
- Extras: switchboard upgrade, roof works, meter change, access equipment (units), strata approvals.
- Ongoing: inverter replacement risk (10–12 yrs typical), periodic cleaning, monitoring.
- Tariffs: grid usage (¢/kWh), daily supply ($/day), solar feed-in tariff (¢/kWh).
- Tax: For owner-occupiers, bill savings are not income; FiT treatment can vary for rentals/business use — confirm with the ATO or a tax adviser.
FAQ (people also ask)
What is a good solar feed-in tariff in Australia 2025?
It varies by state and retailer. Compare cents per kWh alongside daily supply charges and usage rates, not in isolation.
How do I estimate solar payback years?
Payback = upfront cost ÷ annual benefit. Annual benefit = self-use kWh × grid tariff + export kWh × FiT − maintenance.
Is solar worth it for apartments in Australia?
Yes, if strata allows, roof access is viable, and you have strong daytime usage. Smaller systems can still pay back if self-consumption is high.
What ROI should I expect on solar in 2025?
ROI depends on $/kW, tariff/FiT and self-consumption. Use the calculator with your exact plan; many households target simple payback within 4–8 years.
Do I need a battery for good ROI?
No. Batteries help self-consumption but add cost. Start with panels; consider a battery later if your night usage and tariffs justify it.
House vs unit — which saves more?
Houses usually save more due to larger arrays. Units can still do well if self-consumption is high and FiT is reasonable.
Does moving to a time-of-use plan help solar payback?
Often yes if you can shift loads to solar hours and avoid peak rates. Check shoulder/peak pricing and any demand charges.
Are there Australian rebates in 2025?
STC incentives usually reduce upfront cost automatically in quotes. Some states run extra programs periodically — check current eligibility.
Sources / Official References
Disclaimer
This article is for general information only and is not financial advice. It does not consider your objectives, financial situation or needs. Check official government resources or a licensed adviser before making decisions.