⚡ Your Complete Guide to Going Solar with a 5kW System
Thinking about installing a 5kW solar system for your home? You’re not alone. Thousands of Australians are switching to solar every year, and the 5kW setup is among the most popular choices. But is it right for you?
In this guide, we’ll walk through everything you need to know — from costs and expected savings to real-life results, battery options, and more. Whether you’re just curious or ready to install, you’re in the right place.
📑 Table of Contents
- Why Choose a 5kW Solar System?
- How Much Does a 5kW Solar System Cost in Australia?
- Expected Output: How Much Energy Will You Get?
- Will a 5kW System Be Enough for Your Home?
- Battery Options: Should You Add Storage?
- Government Rebates & STCs
- Payback Period & ROI
- FAQs
- Final Thoughts
🔍 Why Choose a 5kW Solar System?
The 5kW solar system is often described as the “sweet spot” for Australian homes. Not too big, not too small — just enough to power an average 3 to 4-person household and offset a significant portion of your electricity bill.
💡 Quick Fact: A 5kW system can generate around 18–22 kWh per day depending on your location and weather conditions.
But the real question is — does it suit your energy usage habits? If your electricity bill is over $300 per quarter, this system is worth serious consideration.
My Honest Experience Living with a 5kW Solar System in Adelaide
If someone had told me five years ago that I’d become “that solar guy” in my neighborhood, I probably would’ve laughed. But here I am — a full-time convert, and I have a 5kW solar system to thank for that.
🌱 How It All Started
Back in 2020, our electricity bills were climbing — and fast. Between running two air conditioners in summer and heaters in winter, plus two kids constantly charging iPads and watching Netflix, we were easily spending $500+ per quarter. It was ridiculous.
I started researching ways to save money, and solar kept coming up. Initially, I thought it was too expensive or only for “green energy warriors,” but after talking to a mate who had just installed a 6.6kW system, I realized it was way more affordable than I expected — especially with government rebates.
So I started calling around for quotes. After comparing three companies, I settled on a reputable installer who offered Tier 1 panels and a Fronius inverter — both with solid warranties.
🔧 Installation Day
The whole process was surprisingly quick. The team arrived around 7:30 AM, and by lunchtime, the panels were on the roof, the inverter was in place, and the system was ready to be inspected. I’ll admit — I was a bit anxious about how it would look on my roof, but they did a clean job. It actually blends in nicely.
One tip I’ll share: ask your installer about shading analysis. I nearly made the mistake of placing panels on the west-facing roof, which gets shaded by a tall gum tree in the afternoon. Thankfully, they spotted it and adjusted the layout.
⚡ What Happened Next
The first few months were honestly amazing. Watching the numbers on my inverter app became my new obsession. On clear days, we were generating up to 22 kWh — enough to cover our daily usage and send some back to the grid.
Our electricity bills dropped from $550 down to around $90–$120 per quarter — just the supply charges mostly, because we were generating more than we used.
One thing I didn’t expect? I became way more mindful of when we used appliances. For example:
- We now run the dishwasher during the day instead of at night.
- I set the washing machine to start at 10 AM.
- My wife even bakes in the afternoon (bonus: fresh cookies).
Shifting our energy use made a noticeable difference in how much we were exporting and how much we saved.
😅 Challenges and Mistakes
Not everything was smooth sailing though.
Mistake #1: Not Understanding My Tariff
I didn’t fully understand how feed-in tariffs worked. I thought I’d make hundreds from feeding energy back into the grid. Turns out — the rates were much lower than I assumed (~7c per kWh at the time). That’s why self-consumption became our main goal.
Mistake #2: No Battery (Yet)
At the time, I skipped the battery because it added over $10k to the cost. In hindsight, I kind of wish I’d gone for at least a small one. During blackouts (which happen 2–3 times a year here), it would be nice to have backup power.
I’m now considering a retrofit battery next year, like a Tesla Powerwall or BYD.
🧠 What I Learned
- The rebate system is a godsend — I got about $2,800 off thanks to STCs.
- Quality matters — Don’t just go for the cheapest quote. Look at panel brand, inverter quality, warranty, and installer reviews.
- Monitor your system — I use an app that tracks generation and usage. It’s eye-opening.
- Plan your roof layout — Ask for a layout diagram and check for shading or obstructions.
- Use your power smartly — Run major appliances during daylight hours to maximize savings.
💰 How Much Does a 5kW Solar System Cost in Australia?
| Location | Average Cost (After STC Rebate) | Installed With Battery |
|---|---|---|
| Sydney | $4,500 – $6,500 | $11,000 – $14,000 |
| Melbourne | $4,800 – $6,800 | $11,500 – $14,500 |
| Brisbane | $4,400 – $6,200 | $10,500 – $13,500 |
| Adelaide | $4,300 – $6,000 | $10,000 – $13,000 |
These prices include installation and Tier 1 panels with a quality inverter. As always, choose CEC-accredited installers to ensure eligibility for rebates and warranties.
⚙️ Expected Output: How Much Energy Will You Get?
A typical 5kW solar system can produce:
- Daily average: 20 kWh (varies between 18–24 kWh)
- Monthly average: 600 kWh
- Yearly output: 7,300 kWh
🌤️ The actual output depends on:
- Roof angle and direction
- Shading
- Geographic location (sun hours)
- Panel and inverter efficiency
🏠 Real Example: A family in Adelaide saved over $1,500 per year by switching to solar with a 5kW system — enough to cover most of their power bill.
🏡 Will a 5kW System Be Enough for Your Home?
Here’s a rough idea of what a 5kW solar system can support:
- Lighting
- A fridge and freezer
- Washing machine
- Dishwasher
- 1–2 air conditioners (moderate use)
- Computer and TV
If you run multiple AC units heavily or have an electric vehicle, you might want to consider a larger system like 6.6kW or 10kW.
🔋 Battery Options: Should You Add Storage?
Adding a battery can increase your self-consumption and reduce reliance on the grid — especially if you’re home in the evenings.
Common Battery Pairings for 5kW Systems:
- Tesla Powerwall 2 (13.5 kWh): ~$12,000
- Sungrow 9.6 kWh: ~$8,000
- BYD B-Box: ~$7,000–$9,000
Is it worth it? It depends on your goals. If you’re after:
- Energy independence ✅
- Blackout protection ✅
- Longer ROI ❌ (battery payback can take 10–15 years)
🎁 Government Rebates and STCs
In Australia, Small-scale Technology Certificates (STCs) can shave thousands off your installation costs.
The number of STCs depends on your location and system size. For a 5kW system:
- You may get 60–90 STCs, each worth ~$37
- That’s a rebate of up to $3,000+
📝 Tip: Always ask your installer for a quote with and without STCs to understand the full cost.
📉 Payback Period & ROI
One of the most common questions: How long before a 5kW solar system pays for itself?
On average:
- Payback period: 3 to 5 years (depending on your electricity usage and feed-in tariff)
- Annual savings: $1,200 – $1,800
- Return on investment: 20%–30% annually — better than most investments!
📌 Pro Tip: Shift energy usage (e.g., laundry, dishwasher) to daylight hours for faster payback.
❓ FAQs
1. How many solar panels in a 5kW system?
Typically 12 to 16 panels, depending on panel wattage (e.g., 330W to 415W per panel).
2. Can I add more panels later?
Yes, if your inverter supports it — or you can upgrade the inverter.
3. What’s the lifespan of a 5kW solar system?
- Panels: 25+ years
- Inverter: 8–15 years
4. Is it worth getting a battery with a 5kW system?
Only if you want energy independence or live in an area with frequent blackouts. Financially, it’s a longer-term investment.
5. Do I still get a power bill?
Yes, but significantly lower — unless your system covers 100% of usage and exports excess.
🔚 Final Thoughts
A 5kW solar system is a fantastic choice for most Australian homes. It strikes the right balance between affordability and energy output — and thanks to rebates and high ROI, it can pay for itself in just a few years.
If you’re ready to cut your power bills and embrace clean energy, now’s the time. Just be sure to work with a trusted, CEC-accredited installer for peace of mind.
