8kW Solar systems: Prices and payback

For households with above-average energy needs, an 8kW solar system offers an appealing stop-gap solution between 6.6kW and 10kW systems while optimising available roof space.

8kW solar systems are also a suitable size for future electrification and pairing with a battery. In fact, they are now as popular as 6.6kW systems and represent a great all-round option for prospective solar owners.

Depending on where you live, an 8kW solar system will generate as much as 35.2 kWh of energy per day in Perth and 28.8 kWh of energy per day in Melbourne.

In this article, we explain essential pricing information, energy output, payback periods, and everything you need to know about installing an 8kW solar systems in Australia.

How much does an 8kW solar system cost?

The average cost of a good quality 8kW Solar System in Australia ranges from $6,700 to $9,800 with Sydney having the lowest average price  at $7,717 and Adelaide the highest at $7,877.

The cost of solar varies in different states around Australia, so it’s important to consider the specific state and territory 8kW solar system price information below. In more competitive markets, prices are slightly lower.

The table below shows the average 8kW solar system price in major cities around Australia:

How much energy does an 8kW solar system produce?

The average daily output from an 8kW solar system in Australia ranges from an average low of  28.8 kWh per day in Melbourne to an average high of 35.2 kWh per day in Perth.

The average residential household in Australia uses around 15kWh of electricity each day.

An 8kW solar system is therefore more than sufficient to meet the average residential household electricity consumption, no matter where you are in the country. It's worth bearing in mind though, that electricity usage is likely to increase as more households electrify their energy and transport.

8kW system output in major cities:

Just like any solar system, the exact output that you can expect will be contingent on a number of factors including:

• Your geographical location
• The orientation and exposure of solar panels
• Shade or any other environmental interferences
• Weather conditions & seasonality
• Efficiency of thesolar panels
• Temperature of panels – overheating can reduce efficiency
• Inverter efficiency

When it comes to how much energy you can expect an 8kW solar system to generate, the two biggest considerations will be your location and the weather. The amount of solar that your system generates will vary according to the season. As you might expect, your output in winter will typically be lower than in summer.

Roof space required for an 8kW solar system

Solar panels are typically rated at 390 to 475 watts of power output per panel. For an 8kW system that means that you would typically require between 17 to 21 solar panels to reach 8000 watts – the same as 8kW.

Given that the average dimensions of a solar panel take up an area of 1.7m², we can calculate that an 8kW solar system would require between 29 to 36m² of roof space to accommodate the 17 to 21 solar panels required to reach 8000 watts. It’s important to consider that while 29 to 36m2 of roof space may be enough to accommodate an 8kW, you’ll likely want some more space to make it easy to access the panels for any future maintenance.

In 2026, if you are quoted a system with panels below 390W, we suggest you organise some better quotes.

8kW Solar system average payback period

How long does it actually take to payback the upfront cost of an 8kW solar system in Australia, and does it still make financial sense to invest in solar?

The figures in the table below assume an average daily electricity consumption of 20kWh, self-consumption rate of 40%, average electricity cost and feed-in rates:

In Australia, the average payback period on an 8kW solar system ranges from 4 - 6.5 years depending on your location. Payback figures are highly sensitive to electricity rates and solar self-consumption rates.

For example, the average electricity price of $0.367 per kWh in Sydney compared to Melbourne's $0.279 per kWh. All things being equal, solar can save Sydneysiders nearly 9c more per kWh.

An accurate 8kW calculation

For more accurate calculations, tailored to your property, we highly recommend using our solar payback calculator.

Lifetime savings for a 8kW solar system

Over the course of 25 years, it's possible that an 8kW system can deliver electricity bill savings in excess of $50,000. Savings like this explain why homes with solar are valued more highly.

8kW System with a battery

If you are looking to install an 8kW system, or already have one, then you're likely considering whether to add a battery to it.

In 2026, there are several compelling reasons why adding a solar battery to an 8kW system is a sound decision - if you can afford it.

• Your system will likely generate a lot of excess energy
• Feed-in tariffs are getting lower and lower
• The battery rebate has reduced the cost of batteries

8kW System with battery price

The price of an 8kW system with a battery depends on the size and brand of the battery to be installed.

The table below shows average prices for an 8kW system with different sized batteries:

Battery size to go with an 8kW system

Several battery sizes are suitable for an 8kW solar system. What size to go with will ultimately depend on your budget and how much daytime electricity you use compared to at mornings and night.

Battery storage between 10 kWh and 27 kWh will be suitable for an 8kW system.

8kW Solar system financials stack up

Our figures indicate that installing an 8kW solar system in Australia can lead to significant savings and payback in good time.

For households looking to electrify, charge an electric car or who already use a lot of electricity, an 8kW system is a good starting point for investigating system sizes. They typically generate enough energy to power daytime electricity use and charge a solar battery.

Irrespective of whether you’re looking at a 3kW, 5kW, 6.6kW, 10kW, or 13kW solar system, it’s important to consider your energy consumption patterns and your property. Reviewing your recent electricity bills, consumption habits, and any applicable state and federal incentives can help you to determine the right solar system for your property.