4kW Solar System Information – Facts & Figures
On This Page:
- How Much Energy Does a 4kW System Produce?
- How Much Space Will It Take Up?
- How Much Does a 4kW System Cost?
- How Much Energy Does It Produce?
Other solar system sizes you may be interested in around the same size:
Slightly smaller 3.75kW system information OR Slightly larger 4.25kW system information.
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4kW Solar Power System Information
Did you know that 4kW solar power systems can consist of a different number of panels depending on the size of the solar panels? Here are some common panel sizes which could make up a 4kW system:
- 330W (12 x solar panels to make 3.96kW)
- 350W (11 x solar panels to make 3.85kW)
- 370W (11 x solar panels to make 4.07kW)
- 390W (10 x solar panels to make 3.90kW)
- 400W (10 x solar panels to make 4.00kW)
- 420W (10 x solar panels to make 4.20kW)
- 450W (9 x solar panels to make 4.05kW)
- 480W (9 x solar panels to make 4.32kW)
- 500W (8 x solar panels to make 4.00kW)
How Much Energy Does a 4kW System Produce?
Depending on where in Australia (or around the world) you are, a 4kW solar system will produce a different amount of energy each day. As an average amount, you can see here how much this system will produce in some of the major regions in Australia by switching between each tab.
| Brisbane, QLD | Sydney, NSW | Perth, WA | Melbourne, VIC | Adelaide, SA | Hobart, TAS | Canberra, ACT | Darwin, NT | |
|---|---|---|---|---|---|---|---|---|
| Daily kWhs | 16.80 | 15.60 | 17.60 | 14.40 | 16.80 | 14.00 | 17.20 | 17.60 |
| Annual kWhs | 6,132 | 5,694 | 6,424 | 5,256 | 6,132 | 5,110 | 6,278 | 6,424 |
What Size Inverter Will You Need/Be Able To Get?
Inverters can be sized differently to your overall panel array.
While your panel array might be 4kW, the inverter could be either less or more than this size. Normally it is bad to have a much larger inverter than panels. It is usually good to have an inverter that is less than the array size.
A 4kW solar array can be put with an inverter with an AC output of 3.00kW.
What you "can" do is not what you "should" do. All inverters have different specs. And based on those specs you might be able to put a LOT more panels on than the rated inverter capacity. That does not mean you should. Thankfully the Clean Energy Regulator has made an "easy ratio" to follow.
The magic number is 1.33333.... You can put up to 1.333 x the kW of panels on what the inverter says and still be eligible for STC incentives.
How Much Space Does a 4kW Solar System Need?
Again, this depends what type of panels you use (in part). This is because as panels get large (in Watts) they also become a little bit more efficient.
A 4kW system using 370W panels will require about 19.3 square meters of roof to be installed.
Each 370W panel measures about 1.75m x 1m.
4kW Solar System Applications
4kW solar power systems are mostly suitable for medium energy users (2 - 4 people). This size of solar power system is classed as "Residential".
4kW Solar System Pricing
A 4kW solar system will certainly cost a different amount depending on the solar business you buy it from. Prices also vary from city to city due to logistics, taxes etc.
To give you some indication though, we believe that the "market price" for a 4kW solar system at the moment is between:
$4,600.00 (on the lower end - e.g. cheap Chinese) to...
$7,000.00 (on the higher end - e.g. tier 1 solar panels and a German inverter - such as SMA).
NOTE: The Prices above are "after-rebate" prices and are only a guide to what you might expect as at Feb, 2026
How Much Does a 4kW System Cost?
The cost of 4kW solar power systems varies. On the lower end, you might expect to get Chinese inverters such as Sungrow, Growatt, JFY, Goodwe etc. and Chinese (lower-tier) panels such as Hannover, Munsterland, ZN Shine etc. You might expect to pay $4,600.00 for such a system.
On the higher end of the spectrum you might be looking at a premium, European inverter like SMA, ABB, Fronius etc. and a tier 1 panel like SUNPOWER, TRINA, WINAICO etc. You might expect to pay $7,000.00 for this type of 4kW solar power system.
Finance Repayments on a 4kW Solar Power System
You could expect to pay somewhere between $153.36 and $226.88 per month as a repayment for your 4kW solar power system.
Note: This figure could vary drastically. It is based on some common solar power finance rates for residential size systems.
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Do I Need A 4kW Solar System?
Whether or not you need a 4kW solar system will depend on many things.
If you are a Residential customer and you use between 15.4kWhs and 24.1kWhs then a 4kW solar system could be a good choice to help reduce power bill costs.
4kW Solar Power System Quotes
Solar Proof Quotes offer a quick and easy way to get 4kW solar system quotes.
Just fill out our quick and easy form to get quotes from great installers in your region who are experienced in 4kW solar power installations.