3kW Solar system: Prices output and savings

Power generation of a 3kW system

If you are a low to moderate energy user with no plans to add a battery in the future, a 3kW solar system may be adequate to power your electricity needs. The amount of solar energy a 3kW solar system generates varies according to your location; in Sydney, it will produce, on average, 11.7kWh per day while in Perth it will generate nearly 13.2kWh per day.

The table below shows the output of 3kW solar systems in major Australian cities:

3kW system output in major cities:
Adelaide 12.6kWh
Brisbane 12.6kWh
Melbourne 10.8kWh
Perth 13.2kWh
Sydney 11.7kWh

Solar panel output varies by season

A 3kW solar system will generate more power in summer and less power in winter. It helps to know these figures and your electricity usage for each season so that you can select the most suitable system size for year-round savings.

graphic for a 3kW solar system showing the sun, solar panels and an inverter

3kW Solar system prices

A good quality 3kW system typically costs anywhere between $3,500 – $5,500 to fully install. System prices vary according to location as the solar rebate adjusts according to how much sunshine your postcode receives. Prices also vary according to the quality of components you select and the company you choose to perform the solar installation.

The table below shows prices for a 3kW solar system in major Australian cities:

Average 3kW system prices in major cities:
Adelaide $4,074
Brisbane $4,000
Melbourne $4,141
Perth $3,990
Sydney $4,017

What about those ads for cheaper 3kW systems?

We advise against going for a budget 3kW system. You may even see prices for 5kW systems that match the prices we publish for 3kW units. Our prices reflect the cost of installing a system good enough to last its 25-year useful life, which means the components, warranties and quality of the install are all better.

Buy with confidence

Savings and payback on 3kW solar systems

The payback period for 3kW systems varies according to your location, electricity usage habits and property specifics like your roof orientation. In some states like Western Australia, a 3kW system can payback within a 4 – 5 year period, while in Victoria it’s more like a 5 – 7 year period.

If you buy solar panels of decent quality, lifetime savings can top $40,000. The savings amount varies according to how you use your solar power and how much electricity you consume during daylight hours. The graphic below shows results from our calculator for a typical 3kW system in Perth:

results from Solar Calculator for a 3kW system in Perth

Accurate 3kW system calculations

For an accurate indication of the payback and savings of a 3kW system at your property, plug in your location, usage and rooftop details into our solar panel calculator to receive your solar results.

Should I consider a larger system?

If you are considering a 3kW system, it may be that your electricity usage is relatively low, or you use little power during daylight hours. Below we list some reasons why you might select a 3kW system:

  • Low electricity usage
  • Do not occupy the property during daylight hours
  • Have no intention of adding a battery
  • Have no intention of powering an electric vehicle

Reasons to select a larger system

Years ago, the sensible approach was to select a system size that output enough to power your daylight electricity needs. Several developments in recent years give cause for you to consider a larger system:

  • Variable feed-in tariffs
  • Lower payback periods
  • Cost vs value of larger systems
  • Ability to add a battery to your system, if not now then later

Price and payback difference for a larger system

If you are considering upgrading from a 3kW unit, you should consider a 5kW solar system as the price you will pay for the additional 2kW is considerably less than what you will pay for the 3kW system. We can explain the price difference by comparing the average prices for 3kW and 5kW solar systems in Brisbane:

  • 3kW system in Brisbane $4,000
  • 5kW system in Brisbane $5,270

The price you will pay per kilowatt:

  • 3kW system = $1,333
  • Additional 2kW = $635

Payback on the extra 2kW

If we assume that you receive a feed-in tariff of 7c, it will only take just under six years to pay back the additional 2kWs, assuming that all of it is exported back to the grid. If you use some of the solar panel output from the additional 2kWs to power your electricity needs, the payback period will be even faster.

Batteries with a 3kW system

If you are considering adding a battery to a 3kW solar panel system, you need to consider whether or not your system will generate enough power to charge the battery.

Typically, a 3kW hybrid system is likely to be large enough if you consume less than 10 – 12kWh per day.

Battery ready system

If you plan on buying a battery ready system and adding solar storage at a later date, we suggest you consider a larger system, either a 5kW or 6.6kW system.

How many panels make up a 3kW system?

A 3kW solar system is typically made up of between 7 – 9 panels that will take up an area of 12 – 15.3m2. If you select the best solar panels that are highly efficient, you may only need eight panels to make up a 3kW system.


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