With electricity prices continuing to rise and more households switching to electric appliances, choosing the right solar system size has become one of the most important decisions when going solar. While the 6.6 kW system has long been considered the standard option, modern Australian homes now use significantly more power than they did just a few years ago.
Air conditioning, pool pumps, home offices, induction cooking, electric hot water systems, and electric vehicles are all contributing to higher daily electricity usage. As a result, many homes are now finding that smaller solar systems no longer cover enough of their daytime energy needs.
In this guide, we explain how much power the average Australian home uses, how solar system sizes compare, and why a 10 kW solar system is increasingly becoming the most practical and future-ready choice for most households.
What Does Solar System Size Actually Mean?
Solar system size is measured in kilowatts or kW and usually refers to the inverter capacity, which determines how much power the system can deliver to your home at any one time under ideal conditions.
For example, a 6.6 kW system typically refers to a 5 kW inverter paired with around 6.6 kW of solar panels, while a 10 kW system commonly refers to a 10 kW inverter paired with a larger panel array, often around 12 to 13.2 kW of panels.
The inverter rating sets the system’s maximum usable output, while the additional panel capacity helps maximise generation across more hours of the day, especially in the morning and afternoon.
A larger system produces more electricity overall during the day. This allows your home to run more appliances directly from solar power, reduce reliance on the grid, and increase long-term savings.
How Much Power Does the Average Australian Home Use?
The average Australian household uses between 18 and 30 kilowatt-hours of electricity per day, depending on household size, lifestyle, and appliance usage. However, total daily usage alone should not be the only factor when choosing a solar system size.
You can use our solar calculator to get an estimate.
The timing of electricity consumption is just as important. Homes that use more power during the day benefit far more from solar generation than homes where most electricity is used at night. For solar-only systems without battery storage, daytime usage determines how much solar energy can be used directly and how much grid power is still required in the evening.
This figure is also steadily increasing due to:
- Widespread air conditioning
- Pool pumps and filtration systems
- Home office setups
- Induction cooktops
- Electric hot water systems
- Electric vehicle charging
Many homes that once used 15 kilowatt-hours per day now regularly exceed 25 kilowatt-hours. This trend is expected to continue as more households transition away from gas and towards full electrification.
This is why solar system sizing should consider both future usage and daily consumption patterns, not just the total shown on a power bill.
How Much Power Does a 10 kW Solar System Produce?
A well-designed 10 kW solar system in Australia typically produces between 30 and 45 kilowatt-hours per day on average across the year. Output varies depending on location, roof orientation, shading, and panel efficiency.
This level of generation allows a household to:
- Run multiple air conditioners during the day
- Operate pool equipment and filtration
- Power home offices and appliances
- Charge an electric vehicle
- Run electric hot water systems
Most importantly, it allows a home to operate primarily on solar power throughout daylight hours, significantly reducing reliance on grid electricity.
Why 6.6 kW Is No Longer the Best Size for Today
The 6.6 kW system became popular because it was affordable, easy to install, and suited older household energy patterns. However, modern homes now place far greater demand on electricity.
Rising Household Power Demand
Australian households consume more electricity than ever before. With air conditioning in most rooms, electric cooking, work-from-home setups, and electric vehicle charging, a 6.6 kW system often struggles to meet daytime demand.
Lower Feed-In Tariffs
Feed-in tariffs have steadily declined across Australia. Exporting excess solar power to the grid now delivers far less financial benefit than it once did. The real value comes from using solar power directly in the home. Smaller systems generate less usable solar energy for self-consumption.
Limited Long-Term Flexibility
Solar systems are designed to operate for 25 to 30 years. Installing a smaller system today can lock a home into undersized generation capacity for decades. Upgrading later is usually more expensive than installing the correct size from the beginning.
Not Suitable for Battery Storage
Most 6.6 kW systems are no longer paired with batteries. Battery storage requires strong daytime generation to charge effectively, which typically means a 10 kW or larger solar system. Smaller systems often cannot generate enough surplus energy to justify a battery investment.
Missed Savings
A 6.6 kW system may reduce power bills, but it often leaves large portions of household usage still being purchased from the grid.
Why 10 kW Is the Most Common and Practical Solar System Size for the Average Home
For most modern Australian households, 10 kW - 13 kW systems represent the most common and practical starting point, offering a strong balance of performance, value, and future-proofing.
It Matches Real Household Energy Use
A 10 kW system is capable of supporting most homes using 20 to 30 kilowatt-hours per day, which now represents a large portion of Australian families. It provides enough generation capacity to meaningfully offset daytime household demand.
It Maximises Daytime Self-Consumption
Larger systems allow more appliances to run directly from solar power, including air conditioning, pool equipment, and electric vehicle charging, increasing the amount of solar energy used inside the home rather than exported.
It Delivers Better Long-Term Value
The cost per kilowatt decreases as system size increases. A 10 kW system delivers stronger lifetime savings and often a faster return on investment compared to smaller systems.
It Is Battery Ready
If battery storage is added in the future, a 10 kW system provides the generation capacity needed to charge batteries effectively. Most battery installations now start at 10 kW or above.
It Future-Proofs the Home
As electricity prices rise and households electrify more appliances, a 10 kW system ensures solar remains effective for years to come. Many medium households with electric vehicles or batteries often move to 13 kW or larger, while larger or three-phase homes frequently trend toward 15 kW and above.
How Much Does a 10 kW Solar System Cost in Australia?
A professionally installed 10.2 kW solar system typically falls within a competitive mid-range pricing bracket when compared to smaller systems.
While a 10 kW system costs more upfront than a 6.6 kW system, the additional generation capacity delivers:
- Greater bill reduction
- Higher long-term savings
- Better protection against rising electricity prices
Over the system lifetime, a larger system almost always delivers significantly greater financial benefit.
Who Should Consider a 10 kW Solar System?
A 10 kW solar system is suitable for:
- Families of three or more people
- Homes with air conditioning
- Pool owners
- Households planning to purchase an electric vehicle
- Anyone wanting strong long-term bill reduction
If your home uses more than 20 kilowatt-hours per day, a 10 kW system is generally the most practical size.
How to Choose the Right Solar System for Your Home
The best solar system is not a generic package. It should be designed around:
- Your roof layout and orientation
- Your daily electricity usage
- Future appliance upgrades
- Battery storage plans
A tailored system design ensures maximum performance, efficiency, and reliability over the life of the system.
Final Thoughts
The 6.6 kW solar system was once the standard choice for Australian homes. Today, it is increasingly undersized for modern energy needs. With rising electricity consumption, lower feed-in tariffs, and the move towards household electrification, a 10 kW solar system has become the most practical starting point for most families.
For many households, especially those with electric vehicles, battery storage, or three-phase power, final system sizes commonly extend to 13 kW or larger. Medium and large homes are increasingly installing systems in the 13 kW to 15 kW range to fully cover daytime demand and future energy growth.
Choosing the right system size from the beginning ensures better savings, stronger performance, and a future-ready energy setup for decades to come. A properly engineered system allows your home to maximise solar usage today while remaining flexible for tomorrow’s energy needs.
If you would like a professionally engineered solar system designed around your household usage and future energy plans, speaking with an experienced solar specialist can help ensure you choose the right system from the start.
