A simple guide for WA homes looking to get solar right the first time
One of the most common questions we get at Solar You is:
“How big should my solar system be?”
Great question — and the answer depends on a few key things, like your power usage, your roof space, and your future plans (think EVs or batteries).
Let’s break it down in a way that actually makes sense.
⚡️ How much power do you use?
Start with your electricity bill — it shows your average daily usage in kilowatt-hours (kWh). Here’s a rough guide:
| Daily Usage (kWh) | Suggested System Size |
|---|---|
| 10–15 kWh | 3–4 kW system |
| 15–25 kWh | 5–6.6 kW system |
| 25–35+ kWh | 8–10+ kW system |
👉 Most WA homes go for a 6.6kW system, which is a sweet spot for price and output — and the largest you can install and still get the full STC rebate without export limits (in most cases).
🏡 Are you home during the day?
Solar works best when you can use the power while the sun’s out.
- Home during the day? A standard system may be enough to slash your bill.
- At work all day? Consider going a bit bigger or adding a battery later to catch and store that daytime power.
🚗 Planning for an EV or battery?
If you’re thinking long-term:
- Getting an electric car? Go bigger. Charging an EV adds around 10–15 kWh per day
- Want battery storage later? Oversizing your solar system now gives you more energy to store and use at night
✅ Good news: We can install a battery-ready system today, even if you’re not buying the battery just yet.
📐 What about your roof space?
- A 6.6kW system usually needs 25–30 m² of roof space
- Bigger systems need more — or higher-efficiency panels if space is tight
- We’ll check shading, orientation, and roof angle to maximise production
💵 What’s the payback period?
The bigger your system, the more energy you can produce — but also the higher the upfront cost.
In WA, a well-sized system typically pays for itself in 3–5 years, and then it’s pure savings for 20+ years after that.
✅ The smart way to size your solar system
Ask yourself:
- How much power do I use now?
- Do I want to future-proof for an EV or battery?
- Can I shift usage to the daytime?
- What fits on my roof?
Still unsure? That’s what we’re here for.
👉 At Solar You, we’ll look at your bills, your home, and your future plans to recommend the right size solar system — no upselling, just honest advice.
