The size solar system someone chooses to install at their property should be selected based on a households annual electricity needs, whether battery storage is going to be added and the size restrictions set in the households location.
The most commonly installed grid-connected solar system sizes for homes in Australia are 5kW-7kW. This is because a 5kW-7kW solar system’s can produce enough energy for a household to run during the day and reduce electricity bills enough to see a fast return on investment.
The larger a solar system is, the more electricity it can generate, meaning the less reliance a household will have on the electricity grid and energy retailers. The less reliance you have on the electricity grid and energy retailers the bigger the reduction on your energy bills.
See our below table for average solar system sizes, estimated production and approximate prices in today’s market.
Please note: Energy production will differ from State to State depending on how many sunlight hours the location receives. See average daily production in Australian major cities here
| System Size | Number of Panels | Estimated Production Annually | System Price (Approx) |
|---|---|---|---|
| 2kW | 8 | 3,000 kWh | $2,510 - $4,860 |
| 3kW | 14 | 4,900 kWh | $2,550 - $6,950 |
| 5kW | 20 | 7,100 kWh | $3,120 - $9,510 |
| 6.6kW | 26 | 10,600 kWh | $3,470 - $10,990 |
| 7kW | 27 | 12,320 kWh | $5,160 - $10,990 |
| 10kW | 36 | 14,380 kWh | $7,660 - $14,100 |
| 12kW | 48 | 16,900 kWh | $14,000 |
How To Determine What Size Is For You
The best way to determine what size solar system will be best suited to you is to look at three key factors; physical space, energy requirements and price.
Physical Space
The space available on your roof may be the deciding factor of what size solar system you opt for. Per solar panel you will require approximately 1.3 m2 of space, with that in mind an average 5kW solar system will have 20 panels in the solar array.
So before deciding on a size solar system it’s best to ensure you know how many panels you can fit on your roof. Solar installers usually provide home visits in the quoting process to assist with determining this.
Energy Requirements
As rule of thumb the most suited solar system size is going to be one that has an estimated energy production which closely matches the amount of energy a household uses. This way the solar system can cover the majority, if not all of your electricity bill.
The best way to determine this is to look at previous energy bills from through out the year and select a solar system size that has a estimated production of your average bill or higher.
As a rough guide you can use the table below to see what size system most closely matches your energy needs. The numbers are for a 1kW system and so can be multiplied by whatever system size you are looking at e.g. 2kW system multiply the numbers in the table by 2. Your average daily consumption per billing period should be displayed on your electricity bill.
| Months | Daily Average (kWh) units |
|---|---|
| September - February | 4.6 - 5.9 |
| March - April | 4.4 - 4.9 |
| May - August | 3.1 - 3.9 |
Price
How much you are willing to pay for a solar system can be the limiting factor on what size you select. However these day solar systems are becoming more affordable due to a drop in prices, Government rebates available and Green loans which assist with the upfront costs.
See our solar system pricing page to view estimated prices in today’s market.
Learn more about the different system sizes below
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