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6Kw & 6.6Kw Solar Systems
(With Optional Battery) Pricing & Information

Home > Solar Panels > Solar Systems > 6Kw & 6.6Kw Solar Systems


We Supply and Install 6kW / 6.6kW Solar Power Systems *with battery options in Melbourne

As solar technology has evolved, the most popular solar systems and components have shifted. Initially, the 3kW system size was the standard, then the 5kW became the norm. And back then, rarely were homeowners purchasing a solar system with a battery.

But now, with significantly lower solar system and solar battery prices coupled with the latest government incentives, the 6.6kW systems *often with a battery have become the #1 choice for Australian homeowners.

Are you ready to benefit from solar electricity? Trione Energy is here to make the process easy and affordable. Contact us and..


6Kw – 6.6Kw Solar System Overview

  • Requires 18 to 24 solar panels, taking up about 32m2 to 43m2 of roof space
  • Generates around 23.8kWh of electricity per day in Melbourne
  • Suitable for households with average power consumption
  • Often paired with a 5kW inverter, which is pre-approved for grid connection
  • Offers potential yearly savings of $1,500
  • Priced between $4,500 – $9,000, or under $3,000 after government rebate
  • Costs $12,500 – $21,000 with a battery storage system


6Kw – 6.6Kw System Size

The average 6.6kW residential solar system in Australia uses either 22-24 panels rated at 275-300 watts each, or just 18 higher-efficiency 370-watt panels. Each panel is around 1.8 x 1 metre, so the total roof space required is typically 32-40 square metres for 6kw / 6.6kw solar systems.

6Kw – 6.6 Kw Solar Energy Production

A 6.6kW solar system produces from 17 to 27kW/h of electricity (annual averaged daily output). While the average Australian household consumes around 20kW/h per day (annual averaged daily consumption). Note: Solar system efficiency will vary due to a range of factors including the location, the weather and the solar system’s components (panels, inverter and battery) 



6.6Kw Solar System Cost Breakdown

Typically, you can expect to pay between $4,500 to $9,000 for a fully installed 6.6kW solar system without a battery, before any rebates or incentives.

The final cost is influenced by the brand and quality of the system components, as well as installation factors like working on multi-story properties.

According to data from Solar Choice’s Solar PV Price Index, the average cost of a 6.6kW solar system in Australia is around $0.98 per watt, which translates to approximately $6,460 after the federal STC rebate has been applied.

At Trione Energy, our 6.6kW solar systems start at just $2,940* after the $1,400 government rebate. If you’re interested in a pricing a 6.6Kw solar system with battery storage, you can expect to add an additional $8,000 to $14,000 to the overall cost of the system. Note: you maybe eligible for 0% solar battery financing through current government incentives.

Additionally, to make solar more accessible, we offer financing options that allow you to go solar with $0 upfront.  Why pay electricity bills when you could pay-off your own solar system instead?

Do You Want to Know Exactly How Much Your 6.6Kw System Will Cost?

Trione Energy is here to help, contact us and receive a written quote, complete with all the system components (solar battery optional), and your eligible government incentives and financing options.


6.6Kw System Payback Period & Savings

Typically, the system will pay for itself in 4-5 years. This assumes that the system design is a good quality one, optimised for your location and level of electricity consumption.

Looking at the full 25-30 year lifetime of a 6.6Kw system, the total potential savings could exceed $37,500. As electricity prices are expected to continue rising, this figure could be even higher.

We will provide a full payback analysis before you go ahead with the installation.

We can also explore the available incentives and finance options for the purchase of your solar energy system.

When the savings on your energy bills are enough to cover the monthly financing cost, the system will pay for itself from day one.

6.6kW system over a 5-year period

To illustrate the savings, let’s examine a 6.6kW system over a 5-year period in a high Feed-in Tariff (FiT) area in Melbourne, VIC. Assuming an installation cost of $6,500, the calculations are as follows:

6.6kW system:
– Solar electricity generated: 40,000 kWh
– Self-consumption: 12,000 kWh
– Electricity exported to grid: 28,000 kWh
– Savings (self-consumption): $3,600
– Income (FiT): $4,200
– Maintenance: $250

Total savings: $7,550 – $6,500 (installation cost) = $1,050 Profit

In this example, the 6.6kW system generates a profit of $1,050 the first 5 years. However, it’s important to note that the system will continue to produce savings well beyond this initial period. As electricity prices continue to rise, the long-term financial benefits become even more apparent.

6.6kW solar system with battery storage over a 7-year period

Let’s analyse the potential savings of a 6.6kW solar system with battery storage over a 7-year period, assuming an installation cost of $15,000 in a high Feed-in Tariff (FiT) area of Melbourne, VIC.

6.6kW system with battery:
– Solar electricity generated: 56,000 kWh
– Self-consumption: 39,200 kWh (70% of generated electricity)
– Electricity exported to grid: 16,800 kWh
– Savings (self-consumption): $11,760
– Income (FiT): $2,520
– Maintenance: $350

Total savings: $13,930 – $15,000 (installation cost) = -$1,070

In this scenario, the 6.6kW system with battery storage has not yet fully paid for itself after 7 years, with a remaining balance of $1,070.

The payback period for a 6kW or 6.6kW solar system with battery storage is typically between 8 and 12 years, depending on a variety of factors.

So, how much money can you save with a 6.6Kw solar system?

On an annual basis, a typical 6.6kW solar setup in a high feed-in tariff area can provide around $1,510 in combined savings and revenue. This breaks down to $720 in self-consumption savings and $840 from exporting excess electricity to the grid, minus $50 in annual maintenance.

Over a 10-year period, those yearly savings add up to approximately $15,100. And accounting for the initial $6,500 installation cost, the total net savings come out to about $8,600 over the first decade.

Solar system savings, output and efficiency will vary due to factors including the components (panels, inverter and solar battery) used in the system. As well as factors including cloud cover and shade, location, roof orientation and of course, the weather and specifically the amount of direct sun exposure.

What to know how much you’ll money you’ll save?

Trione Energy is here to help, contact us and receive a full payback analysis before you decide.



Choosing a Solar System

When choosing the best solar system size, you should consider your daytime electricity consumption, available roof space, budget, feed-in tariffs, electricity rates, and future energy needs. Assess these factors to find the optimal balance between upfront costs and long-term savings.

Is a 6Kw Solar System with Battery Right for You?

When considering whether a battery-powered solar system is the right choice for your home, evaluate the following 5 factors:

1. Energy consumption patterns: If you have high energy consumption during evening hours or at night when solar panels are not generating electricity, a battery system can help you store excess energy produced during the day for later use. If your energy usage is primarily during daylight hours, a battery may not provide significant additional benefits.

2. Electricity rates: If your area has time-of-use (TOU) electricity rates, where the cost of electricity is higher during peak hours (usually evening and night), a battery system can help you save money by using stored solar energy during these expensive periods. If your electricity rates are flat, the financial benefits of a battery may be less pronounced.

3. Energy independence: If your goal is to achieve greater energy independence or have a reliable backup power source during outages, a battery system can provide these benefits. If your primary focus is on maximising financial savings, a battery may not be the most cost-effective solution.

4. Upfront costs: Battery systems add a significant upfront cost to your solar installation. If your budget is limited, a solar system without a battery may be a more affordable option. However, if you have the financial means and value the benefits a battery provides, it can be a worthwhile investment.

5. Government incentives: The Solar Homes Program in Victoria, Australia offers interest-free loans of up to $11,000 for eligible households to install solar battery systems that meet specific technical and safety requirements. The loan is provided by the State of Victoria, with repayments made via monthly direct debit over a 5-year term. Applicants must pass credit checks, and the battery must be installed by an accredited installer before the loan is approved, with assistance available for those experiencing financial hardship.

Is a 6.6kW System Right for You?

Whether you’re interested in a 6.6kW solar system with battery storage or are undecided which system is best suited, Trione Energy can help.


6.6Kw Solar System FAQ’s

Why is the inverter only 5Kw?

Yes, this is something that confuses many people. There are a couple of reasons why a 5kW inverter is often used with a 6.6kW solar energy system.

  • A 5kW inverter is cheaper and pre-approved for grid connection
  • Greater choice of 5kW inverters on the Australian market
  • Many electricity distributors allow 5kW inverters to be ‘oversized’ by133% (6.6kW)
  • So a 5kW inverter can handle a 6.6kW solar energy system easily.

There are 6kW inverters available. They are more expensive, there is less choice of brands, and they are not pre-approved for connection to the grid. It’s possible to get an inverter larger than 5kW approved for grid connection. But there’s a lot more red tape involved, and unless you’re going to run a commercial system, it’s generally not worth the hassle.

The maximum output of the solar panel array can be 133% of the maximum rating of the inverter. This is refers to ‘oversizing’.


What is Oversizing?

Oversizing is a common practice in Australia where a solar system is designed with a higher solar panel capacity than the rated capacity of the solar inverter. For example, the 6.6kW solar systems commonly use a 5kW solar inverter.

The key reasons for oversizing are:

Solar Rebates: In Australia, the solar rebates and incentives are calculated based on the total solar panel capacity installed, not the inverter size. By oversizing the solar panels, you can maximise the available rebates and subsidies.

Inverter Limitations: Most electricity distribution networks in Australia allow single-phase inverters up to 5kW to be “oversized” by up to 133% of the inverter’s rated capacity. This means a 5kW inverter can be used with a 6.6kW solar panel array without any issues.

Cost Optimisation: Larger solar inverters tend to be more expensive than smaller ones. By using a 5kW inverter with a 6.6kW solar system, you can optimise the system cost while still benefiting from the maximum solar panel capacity.

So in summary, oversizing the solar panel capacity compared to the inverter size is a common and safe practice in Australia that allows homeowners to maximise their solar incentives and optimise their system costs.


What is the Levelised Cost of Storage, and why is it important?

The Levelised Cost of Storage (LCOS) is a metric that compares the cost-effectiveness of energy storage systems over their lifetime, considering factors such as capital cost, operating costs, and energy output. It is important because it helps consumers, investors, and policymakers make informed decisions about the most cost-effective storage solutions for their needs, such as determining the viability of installing a battery system alongside a 6.6kW solar array.

What types of grid-connected energy storage systems are available?

The main types of grid-connected energy storage systems that can be paired with a 6.6kW solar system are:

  1. AC-coupled systems: The battery is connected to the home’s AC electrical system, alongside the 6.6kW solar inverter.
  2. DC-coupled systems: The battery is connected directly to the 6.6kW solar array’s DC output before the solar inverter.
  3. Hybrid systems: Combine both AC and DC coupling for greater flexibility and optimization, suitable for a 6.6kW solar setup.
  4. Standalone systems: Not directly connected to the 6.6kW solar panels; charge from the grid during off-peak hours and discharge during peak hours.


Have more questions? Trione Energy is here to help.


More Reading


Does It Pay to Install More Than 6kw of Solar Panels?

3 kW or 6.6 kW? Is Bigger Always Better? Here’s the common question: how many solar panels should I install? The simple answer is…

What Size Solar System Do I Need

….including, how big your house is, what times of the day and how much power consumption…How much you want to save on your power bills…



Get a 6.6Kw Solar System Quote

Trying to figure out the best solar system for your home can feel overwhelming. But the team at Trione Energy is here to make it easy.

We’ll start with a free consultation to understand your energy needs, budget, and goals. Then we’ll custom-design a solar solution – whether that’s a 6.6kW system or one with battery storage – that’s tailored specifically for you.

No more guessing games. Just personalised guidance from solar experts to help you make the right investment. Ready to get started?