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Everything You Need to Know About a 12kw Solar System

12KW Solar System Australia

Transitioning to solar is never easy, especially if you have a home or property with high energy demands. While a 12kW solar system can lead to substantial savings on electricity bills, getting the size of your system wrong can be detrimental to your wallet – you shouldn’t be spending too much money upfront.

However, if you think (or know) that your property requires a large volume of electricity, a 12kW solar system may be just for you. In this article, we’ll take a closer look at the cost, electricity production, and roof space requirements of a 12kW solar system. Then you can assess whether this type of system is a good fit.

Who is best suited for a 12kW solar system?

A 12kW solar system is best suited for you if you have a very large property with high energy demands and a large roof to house the panels. This type of property may include a large family home that is also home to a business, or a luxury home for a large family, with a slew of appliances and lights.

In comparison, an average home consumes around 20-30kWh each day, which requires a 6-7kW solar system. A 12kW solar system, on the other hand, is considered large as it is usually more than enough to offset the energy needs of small to large families. If you have a daily power usage ranging from 48 to 60 or more kWh, then a 12kW will suit you.

How much power can a 12kW solar system produce?

The power generation of a 12kW solar system varies from one home to another. It depends on factors like your geographic location, shading in the area, the quality of the solar panels, maintenance, and cleaning, among other factors.

On average, a 12kW solar system can produce around 60kWh of power per day – provided your panels receive at least five peak sun hours a day.

Peak sun hours are different from place to place. Let’s take an example from two major cities in Australia, Perth and Melbourne. Perth has 5.5 peak sun hours while Melbourne averages only 4.1, and is generally cooler.

A 12kW solar system in Perth can generate a whopping 66kWh, while the same system in Melbourne will produce 49.2kWh. You can see the electricity yield for some other major cities in Australia in the table below.

City, StateAverage Daily Peak Sun HoursElectricity Production
Darwin, Northern Territory6.2 hours74.4kWh
Perth, Western Australia5.5 hours66kWh
Mildura, Victoria5.5 hours66kWh
Brisbane, Queensland5.1 hours61.2kWh
Sydney, New South Wales4.5 hours54kWh
Melbourne, Victoria4.1 hours49.2kWh
Adelaide, South Australia4.8 hours57.6kWh
Hobart, Tasmania3.8 hours45.6kWh

Those numbers do not take into account other factors such as the panels’ quality and the presence of shading around the system.

How many solar panels are in a 12kW solar system?

A 12kW solar system requires double the number of solar panels, compared to the average 6kW system. The amount of solar panels in a 12kW solar system also depends on the size of your chosen panels.

Differences in the panel dimensions are usually not that significant. You can see the differences in two of Trina’s modules as an example:

Trina Vertex S 400W: 1754×1096×30 mm

Trina Honey M 330W: 1690 × 996 × 35 mm

Your 12kW solar system will require 27-36 panels based on your solar panel choice. Here’s a more detailed list: 

330W (36 panels to produce 11.88kW)340W (35 panels to produce 11.90kW)360W (33 panels to produce 11.88kW)370W (32 panels to produce 11.84kW)380W (32 panels to produce 12.16kW)390W (31 panels to produce 12.09kW)400W (30 panels to produce 12kW)410W (29 panels to produce 11.89kW)415W (29 panels to produce 12.03kW)420W (28 panels to produce 11.76kW)430W (28 panels to produce 12.04kW)440W (27 panels to produce 11.88kW)

How much roof space does a 12kW solar system require?

While a 12kW solar system allows you to generate enough electricity for a large household, it comes with a hefty requirement in terms of roof space. To install a 12kW solar system, you’re going to need around 75m2 of free space.

If you have limited roof space, you can opt for high-power output panels such as 400W Trina Vertex S or Jinko Tiger Pro. On the other hand, properties with expansive roof space can opt for both high or low-power output panels.

Pricing, Payback, and Saving


Depending on the quality of your solar panels and overall system, a 12kW solar system can cost from $13,000 for a lower-end system to $21,000 for a higher-end system.

Location also plays an important role in solar system pricing as it can affect the solar panel’s price and the availability of the rebate you receive. Always ask for multiple quotes to ensure you’re getting the best deal in terms of total installation cost.

Payback and Savings

The average payback period for a 12kW solar system is around 3 to 6 years. It all comes back to your choice of system and your electricity consumption. It’ll be even longer if you add batteries to your system, which can add another 2 to 4 years depending on the battery size and initial investment.

To shorten the payback period, you can maximise electricity use at home by performing electricity-heavy activities when the sun is at its peak, such as laundry or charging EVs.

You can expect to save around 20 cents (or more) for every kWh you spend from solar-generated electricity and 5 to 13 cents for every kWh you fed back to the grid. In total, you’ll save up to around $900 to $1,200 per quarterly bill, on average.


Building the perfect solar system for your home can be challenging, but it’s worth every penny in the long run. If you’re looking for a high-quality solar installer to build your 12kW solar system, Sungain Solar is here to help.
Contact us today for more information or fill out the form below for a free no obligation quote.

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