How to Choose Between a 10kW and 5kW Solar System: A Practical Guide for Australian Homeowners

With energy prices on the rise and sustainability becoming a major concern, installing a solar system in your home isn’t just a smart move—it’s almost essential. Among the most popular options in Australia today are the 10kW solar system and the 5kW system. But which one suits your needs, budget, and lifestyle best?

This article explores both systems in detail, helping you make an informed decision that will pay off for years to come.

🌞 Why Solar Power Is More Relevant Than Ever

Australia is one of the sunniest countries on Earth, which makes it ideal for harvesting solar energy. Add to that generous government incentives, the ability to sell energy back to the grid, and rapidly falling solar panel prices—and you’ve got a no-brainer investment.

But when it comes to sizing your solar system, many homeowners find themselves stuck between the 5kW and 10kW options. The right system for you depends on factors like:

• Your current and future electricity usage

• The size and orientation of your roof

• Budget and expected ROI (Return on Investment)

• Whether you want to add battery storage

⚡ What Does a 10kW Solar System Deliver?

A 10kW solar system is considered a large residential or small commercial solar setup. It typically includes 25–28 solar panels, depending on the wattage of each panel, and needs approximately 55–65 square metres of roof space.

Average Daily Output:

• Around 40–44 kWh/day, depending on location and weather conditions

• That’s enough to power a large household or a small business

Ideal For:

• Homes with 4+ bedrooms and high energy demands

• Properties with ducted air-conditioning, heated pools, or electric vehicles

• Families planning to grow their energy usage over time

Benefits:

• Significantly reduces electricity bills (up to $4,000–$5,000 annually)

• Allows for higher feed-in tariff income (selling excess power to the grid)

• Future-proofs your home as energy needs increase

🧮 Cost vs. Value of a 10kW System

While the upfront cost is higher compared to smaller systems, the long-term savings are substantial. Depending on rebates and installation complexity, a 10kW system can cost anywhere between $8,000 to $14,000.

But with energy savings and solar incentives, the average Australian homeowner can see a full return on investment within 4 to 6 years.

When a 5kW Solar System Makes More Sense

A 5kW solar system is perfect for average-sized households with moderate energy usage. It generally includes 12–15 panels and requires around 25–35 square metres of roof space.

Average Daily Output:

• Around 18–22 kWh/day

• Sufficient to cover 60–80% of a typical home’s energy needs

Ideal For:

• Households of 2–4 people

• Homes without electric vehicles or large appliances

• Roofs with limited space or shading issues

Benefits:

• Lower upfront cost (approx. $4,000 to $7,000)

• Faster payback period—often 2 to 4 years

• Easy to expand or add battery storage later

Key Differences at a Glance

💬 What About Batteries?

Both 5kW and 10kW solar systems can be paired with batteries, but the benefits increase with system size.

10kW + Battery:

• Excellent for off-grid setups

• Store more power for night-time use

• High savings and energy independence

5kW + Battery:

• Suitable for evening use

• Can reduce reliance on grid electricity

• More affordable upfront, but limited storage

 Environmental Impact

By switching to solar:

• A 10kW system reduces 13–16 tonnes of CO₂ emissions annually

• A 5kW system cuts down about 6–8 tonnes per year

Either way, you’re significantly reducing your carbon footprint while also saving on electricity costs.

Installation and Rebates

Both systems are eligible for:

• Small-scale Technology Certificates (STCs), reducing your system cost

• State-specific rebates (in some cases)

• Feed-in tariffs, helping you earn money from excess energy

Always work with a CEC-accredited installer like Esteem Energy to ensure compliance, performance, and warranty support.

Final Takeaway: Choose Smart, Save Smart

There’s no one-size-fits-all answer when choosing between a 10kW and 5kW solar system. It all depends on your household’s needs, budget, and future plans.