Home Solar Sizing Guide: Best Panel Brands & Costs⚡ Australia

AVERAGE SOLAR SYSTEM SIZES IN AUSTRALIA

In Q4 2025, the average NSW solar system was 11.6kW. So should I just get an 11.6kW solar system? Not necessarily. 

Because each household will have its own consumption habits, budget, and goals which will determine the best solar system size, however, based on averages, anything around 6.6kW - 10kW is popular, with some opting for larger 15kW+ systems.

The average solar system size is increasing over time due to factors like higher electricity bills, heavy air conditioner usage, more EVs entering the mix, and the ability to store excess solar with energy storage.

Overall, elements like your usage, budget, and goals will determine how many solar panels you’ll need, however systems between 6.6kW - 15kW are common amongst Australian homes.

How many panels is a 10kW solar system? If you opted for a 10kW solar system installation with 470W solar panels, you’d be looking at around 21 solar panels for your roof. (10,000W ÷ 470W = 21.3 Panels).

Not only do solar systems vary in size, but solar panels themselves also vary in power out capacity. Measured in Watts (W), a solar panel is measured by the total power output a panel can generate. (e.g. 440W and 470W solar panels).

440W solar panels used to be industry standard, but with advancements in solar technology, we now have the ability to harness up to 470W of solar generation in the exact same footprint. This means you can get more out of fewer panels.

Solar PV panels vary in specifications and features depending on the brand, with some offering bifacial benefits, higher wattage, or heavier duty protection. Elements like shifting to N-type and half-cell designs enable manufacturers to incrementally improve module performance, benefiting the end-user.

For most residential homes, solar panels range around 470W (0.47kW), which is perfect for solar system sizes like 6.6kW and 10kW systems etc.

WHAT'S THE BEST SOLAR SYSTEM SIZE FOR HOMES?

The 'best' solar system size will greatly depend on your usage and goals.

The average household energy consumption throughout is approximately 17.2 kWh (6,278kWh per year)* in the Newcastle & Maitland area. This mostly varies between 15-25kWh daily.

Whilst a professional will have more insight into solar system design and optimal efficiency, calculating the best solar system comes down to a few factors including:

• Average Household Energy Consumption & Timing
• Roof Space & Available Array Real Estate
• Budget & Energy Goals
• Energy provider FiTs

Throughout an average day, there's the equivalent of approximately 4.5 hours of peak sunlight per day. Using this estimate, a 470W panel would produce around 2.1kWh (2115Wh) per day. This means you can calculate your system size to the number of panels required to meet your daytime consumption.

*according to Ausgrid 2023-24 data.

33% SOLAR SYSTEM RULE EXPLAINED + GRID REQUIREMENTS

When installing solar anywhere in NSW, it's worth considering the requirements set by your local energy provider (DNSP), who are responsible for maintaining the grid and its compliance.

Whilst DNSP requirements vary, each provider will have their own guidelines for what needs approval. For example, Ausgrid states that households can get up to 10kW per-phase (based on the inverter size).

This means that a single-phase house can install up to 10kW of solar, and a three-phase home can install up to 30kW as it has three phases.

However, there's a little trick installers like to use - where a solar system can be oversized by up to 33% as the 10kW per phase capacity per phase refers to the inverter rather than the amount of panels on your roof.

For example, a 10kW inverter can be paired with 13.3kW of solar capacity and a 5kW inverter can pair with a 6.6kW solar system to suit the requirements.

The 33% rule is why we rarely see the same solar and inverter size installed, as the additional production helps produce more solar energy in the mornings & evenings.

6.6kW Solar System Cost

For smaller, 2-3 person households, a 6.6kW solar system is optimal, providing from $1,200-$1,500 in savings, which costs around $6,000-$9,600*.

8kW Solar System Cost

For slightly larger medium-sized homes, an 8kW solar system is recommended for savings around $1,500-$1,900 annually, and costs around $8,250-$12,000*.

10kW Solar System Cost

Large households with 4-5 people could take advantage of a 10kW solar system which costs around $9,750-$13,600* and saves approximately $1,900-$2,400 per year.

ANALYSING YOUR ELECTRICITY BILL: HOW TO SIZE YOUR SYSTEM RIGHT

By analysing your most recent electricity bill, homeowners can gain insight into consumption statistics like average daily energy usage and when they're using most of their energy, to determine the ideal solar system size.

Your quarterly energy consumption will vary throughout the seasons with different production in summer vs. winter, so it's also worth analysing past bills for historical data.

If your usage is highest during summer when the air conditioner is on continuously, or you're about to get an electric vehicle, it's going to be worth accommodating the higher energy usage with a larger system to really offset daytime usage.

The primary goal is to determine the right sized solar system to accommodate your lifestyle & consumption which will be unique to you.

1. Trina Solar

Trina Solar has built a strong reputation across Australia for reliable, high-performing solar solutions. Their Vertex series caters to both homes and commercial projects, offering efficiency, durability, and design appeal.

With solid local support and long-term warranties, Trina remains one of the most trusted solar manufacturers globally.

We love and recommend Trina's Vertex S+ series modules.

2. JA Solar

As one of our most installed solar brands, JA Solar is known for dependable performance and strong value.

The company's focus on efficiency and cost-effectiveness has made them a popular choice among installers and homeowners seeking reliability without premium pricing.

Our most installed JA solar modules: The JA Solar DeepBlue 4.0 Series.

3. TW Solar

Being one of the world's largest vertically integrated solar companies, TW Solar produces every part of their modules in-house.

Their panels are known for consistent output and robust build quality, making them well-suited to Australia's diverse climates. TW's growing market presence highlights their balance of quality, innovation, and long-term performance.

Our TW top pick: TW TNC 2.0 Module Series.

SOLAR-ONLY VS. BATTERY STORAGE: WHICH IS BETTER?

As previously mentioned, a typical NSW home consumes anywhere between 15-25kWh of electricity per day, but this doesn't really reflect when the energy is being used.

Even if you've got a solar system that produces more energy than you use, it's very possible that you're using expensive grid electricity in the evenings when the sun is down.

One of the biggest mistakes that solar owners make is using the majority of their electricity when their solar isn't generating.

For solar owners who need evening usage, a battery addition is a great way to maximise your daily production. If your system is sized correctly, the excess charges the battery to be used later - maximising your generation.

By analysing your electricity bill, you can see when you use most of your energy throughout off-peak, shoulder, and peak periods, all in-which will help you size the right solar and/or battery.