Reviewed by Leigh McInerney
Average Cost of a 12kW Solar System by City in Australia
The cost of a 12kW solar system varies slightly from city to city. The table below shows the average price of the system in major cities in Australia.
| City | Average cost | Average cost per watt |
|---|---|---|
| Adelaide, SA | $12,831 | $1.01 |
| Brisbane, QLD | $12,831 | $1.01 |
| Canberra, ACT | $12,831 | $1.01 |
| Hobart, TAS | $13,779 | $1.43 |
| Melbourne, VIC | $13,779 | $1.43 |
| Sydney, NSW | $12,831 | $1.01 |
| Perth, WA | $12,831 | $1.01 |
| Average | $13,237 | $1.13 |
How Much Power Does a 12kW Solar System Produce?
A 12kW solar system produces around 45kWh per day on average. However, location, climate, shading problems, solar panel tilt/orientation, and quality may affect the system’s output.
The solar industry uses Peak Sun Hours (PSH) to calculate the output of solar panels. One peak sun hour is assumed to equal one hour because different regions receive different strengths of sun rays during a particular time of the day.
How To Calculate Solar System Output
An efficient 12kW solar system generates about 45 units per day. But how do we reach this figure?
The output of a particular solar system is calculated using the following formula.
Solar system watts (12kW) x Peak Sun Hours (PSH) x75% = daily watts hours.
Since no solar panel can be perfectly efficient, the actual output is derated to 75% because of the panel’s variables.
Below is a practical example for a 12kW solar system.
12kW x 5.0PSH x 75% = 45kWh
12kW Solar System Output in Australia’s Capital Cities
| City | Approximate average daily energy yield | Approximate average annual energy yield |
|---|---|---|
| Adelaide | 43kWh - 49kWh | 18,396kWhs |
| Brisbane | 47kWh - 49kWh | 18,396kWhs |
| Canberra | 43kWh - 49kWh | 18,834kWhs |
| Hobart | 35kWh - 40kWh | 15,330kWhs |
| Melbourne | 37kWh - 43kWh | 15,768kWhs |
| Sydney | 41kWh - 46kWh | 17,082kWhs |
| Perth | 48kWh - 53kWh | 19,272kWhs |
| Darwin | 50kWh - 55kWh | 19,272kWhs |
How Much Can I Save With a 12kW Solar Power System?
A 12kW solar system can save you between $900 and $1,200 every quarterly bill or around $4,500 a year.
However, the actual money you can save from your system depends on the following two factors:
- The solar feed-in tariff you get for the power you export to the grid
- How much electricity you consume at the time of generation
Solar Feed-In Tariffs
Electricity costs around 18 to 30 cents/kWh on average, while the current Feed-in-Tariff rate in the market ranges between 9 cents/kWh and 13 cents/kWh.
However, solar Feed-in-Tariffs are no longer the main incentive mechanism, and the rates have been significantly reduced. So, to get the most out of your solar system, you should consume most of the power it produces.
Self-Consumption
Every unit of solar power you use is a unit of electricity you do not need to buy from the grid. Therefore, you can save about 20 to 30 cents/kWh depending on the cost of your electricity.
How Many Solar Panels for a 12kW Solar System?
A 12kW solar power system can consist of around 36 to 50 solar panels depending on their size. Check out the common panel sizes that can make up a 12kW system.
- 50 x 240W solar panels to make 12kW
- 48 x 250W solar panels to make 12kW
- 46 x 260W solar panels to make 12kW
- 40 x 300W solar panels to make 12kW
- 37 x 330W solar panels to make 12kW
- 36 x 335W solar panels to make 12kW
The panel size you choose will depend on the size of your roof.
What Is the Average Payback Period?
The payback period for a 12kW solar system is around 3 to 6 years. Based on the annual 5% increase in the cost of electricity, you can expect to pay back your solar system within 6 years if you use 100% of the power produced by your system.
You will still need to pay for the maintenance of your system and replace your solar inverter after 15 to 20 years. But this is nothing to worry about if you will enjoy free electricity for more than two decades until your system becomes inefficient.
Finance Repayments on a 12kW Solar Power System
To fully pay for your 12kW solar system, you will need to make monthly repayments of between $400 to $650 every month.
Note: This figure varies drastically depending on the finance rates for residential solar power in your state.
How Much Roof Space Does a 12kW Solar Energy System Need?
Your roof space will determine the size of solar panels to choose from. Panels with higher wattage tend to be more efficient, so you only need a few on your roof.
If you use 250W panels (each measuring approximately 1.7 m x 1m), you will need about 20.4 square meters of roof space.
What Can I Run With a 12kW Solar System?
A 12kW solar system can run several household appliances, including washing machines, lights, air conditioners, water pumps, etc.
If you decide to go entirely off-grid, below is a home system load reference to help you understand how you can use your 12kW system.
| Load Name | QTY | Load Rated Power | Total Rated Power |
|---|---|---|---|
| Lights | 20 | 11W | 220W |
| Fan | 4 | 80W | 320W |
| Computer | 2 | 150W | 300W |
| Refrigerator(240L) | 2 | 180W | 360W |
| Printer | 2 | 250W | 500W |
| Fax machine | 1 | 150W | 150W |
| Washing machine | 1 | 300W | 300W |
| Electric stove | 1 | 1000W | 1000W |
| Microwave | 1 | 1500W | 1500W |
| Electric cooker | 1 | 300W | 300W |
| Air conditioner(2HP) | 4 | 1500W | 6000W |
| Satellite TV receiver/VCD | 2 | 50W | 100W |
| Colour TV(32 inch) | 2 | 150W | 300W |
| Water Pump | 1 | 200W | 200W |
| Total | 11550W | ||
Note: This is just for reference as different households have different needs and preferences.
Also, keep in mind that water pumps, air conditioners, and refrigerators are inductive loads, so their starting power is three to six times more than normal power. To use this equipment, ensure you turn on the inductive load first.
12kW Solar System Key Numbers
| Description | Key numbers |
|---|---|
| Number of panels | From 36 x 335W panels to 50 x 240W panels |
| Power output | 45kWh per day |
| Potential savings | Between $900 and $1,200 every quarterly bill depending on the cost of electricity |
| Average payback period | 3 to 6 years |
| Cost | $13,000 to $18,000 |
| Suited to | Large homes with more than average power needs |
12kW Solar Energy System With Battery Storage
A 12kW solar system generates an average of 45kWh per day. So, a battery with a capacity of 33.6kWh would be enough for your system.
A battery calculator will help you know the exact number of batteries needed for your solar system.
Battery storage allows you to be more independent from the grid. However, battery backup options are quite expensive and may increase your payback period. Therefore, you should seek professional advice before installing battery storage for your solar system.
FAQ's
Yes, a 12kW solar system is an excellent investment for large households with high power needs. They can also help reduce electricity bills for small businesses.
The industry standard lifespan for solar panels is about 25 to 30 years when their efficiency drops below 80%. This is also the time when the panels’ performance warranty expires. You can still use the panels for several more years if their efficiency is not too low.
Yes, solar panels need maintenance to keep them in good shape. It is recommended to clean your solar panels every 6 months to one year to maintain their productivity, effectiveness and efficiency.
However, you may need to clean more frequently depending on the area you live in and how fast the panels accumulate dirt.
The national average solar panel maintenance cost is around $400, with an average range of between $300 to $700. On the low end, you can pay about $150, while the high-end cost can go up to $1,000.
This cost depends on where you live, your solar system size, roof orientation and the amount of dirt on the panels.
Yes, solar panels can potentially increase the value of a home because they help reduce monthly electricity bills. Most buyers are likely to buy homes with a solar system because of the potential savings from electricity bills.
Solar batteries have a lifespan of 5 to 15 years, depending on their type and quality. If you install a solar battery, you will need to replace them to match your solar panels’ 25-30-year lifespan.
There are several top-notch solar panel brands that provide high efficiency, performance and reliability.
The table below shows the best solar panels efficiency and material warranty.
| Manufacturer | Panel efficiency | Material warranty |
|---|---|---|
| Sunpower | 22.8% | 25 years |
| LG | 22.1% | 25 years |
| REC | 12.9% | 25 years |
| Panasonic | 21.7% | 25 years |
| Q CELLS | 21.4% | 25 years |
