How Much Power Will a 6.6 Kw Solar System Produce? And Is It Enough?

Energy Matters - Australia

Undoubtedly, the average size of a solar power system is getting bigger.  Many years ago, most households bought 3kW solar power systems (approximately 12 panels).  Now, a 6.6kW solar system size (around 24 panels) is all the go [updated on 24 January 2023].

The big question is why?

There are three main reasons:

  1. The cost of solar power systems keeps falling, making bigger systems more affordable.
  2. More panels = more STCs (the Federal Government’s ‘rebate’) = a bigger point of sale discount for you!
  3. 6kW is a great size for anyone considering adding a battery.

How many panels are in a 6.6kw solar system?

The output might vary, but it’s normal to find solar panels between 300 and 400 watts each today.

The total number of panels determines the size of a solar system. Using a 330w solar panel as an example, a 6.6kW solar system requires 20 × 330w solar panels.

6.6 kW solar system how many panels

Solar panels are different models of capturing and producing electricity. For instance, residential solar uses a 6.6 kW system.

The number of solar panels x output = Solar system size

20 x 330W panels = 6,600 W or 6.6kW solar system

Your system may have 20x330W panels. It’s a 6600W (6.6kW) system, which is important.

A solar photovoltaic (PV) system’s size or capacity is the maximum amount of electricity it can produce. It isn’t about the number of solar panels but the system’s overall capacity.

Your daily energy consumption and the size of your solar system determine the number of solar panels required for your home: the more solar panels you require, the larger your solar system. The table below is a guideline based on most panels’ wattage.

PANEL WATTAGE
UP TO 6.66kW IN MAXIMUM PANELS
TOTAL SYSTEM SIZE
250
26
6.500 kW
255
26
6.630 kW
260
25
6.500 kW
265
25
6.250 kW
270
24
6.480 kW
275
24
6.600 kW
280
23
6.440 kW
285
23
6.555 kW
290
22
6.380 kW
295
22
6.490 kW
300
22
6.600 kW
305
21
6.405 kW
310
21
6.510 kW
315
21
6.615 kW
320
20
6.400 kW
325
20
6.500 kW
330
20
6.600 kW
335
19
6.365 kW
340
19
6.460 kW
345
19
6.555 kW
350
19
6.650 kW
355
18
6.390 kW
360
18
6.480 kW
365
18
6.570 kW
370
18
6.666 kW
375
17
6.375 kW
380
17
6.460 kW
385
17
6.545 kW
390
17
6.630 kW
395
16
6.320 kW
400
16
6.400 kW

How many solar panels are needed for a 5kw system?

Using 415W solar panels, you will need 12 to create a 5kW solar system, producing 4.98kW.

Since each panel will be roughly 1.8 meters by 1.1 meters, you’ll require a roof area of at least 23.7 meters squared.

A 5kW solar power system used to be all the rage.  But solar suppliers – and their customers – have done the maths and worked out that going 6.6kW can be a better value.  And by 6.6kW, I mean that 6.6kW of solar panels are installed on the roof, with a 5kW inverter.

solar system size is largely limited by how many solar panels you can fit on your roof
Solar inverters are the brains of the solar operation, but panels like these are the workhorses.

Is that solar system size allowed, you ask?

Yes!  It is legitimate, according to the Clean Energy Council guidelines and the network distributors (the companies that own the poles and lines).  

However, the network owners that distribute electricity, known as the Distribution Network Service Provider (DNSP) or simply the distributor, choose to limit the number of solar panels and inverters that can install in your home, not the energy retailer.

The rule is that you can oversize your solar power system by 133%. This means you can get an inverter with a 5kW capacity and add 6.6kW solar panels (5kW x 133% = 6.6kW).

Most single-phase residences are limited to a 5kW inverter and 6.6kW solar panels. Despite this, some households can have up to 10kW, and three-phase homes can have up to 30kW.

Despite the green energy revolution, distributors are concerned that too much electricity streaming into the grid would cause older power plants to fail. The grid must maintain a constant voltage. Excessive solar input or feed-in raises the voltage.

Visit our page to learn more about how much rooftop solar power you can install through state-by-state guidelines. Check out our tips for getting a solar power system or solar panels.

Top benefits of a 6.6kW solar system size

  • You maximise the STCs without upgrading the inverter from 5kW to 6kW. This saves you a few hundred bucks. And most importantly – from a ‘value for money perspective – it lowers the cost/watt of your solar system.
  • 5kW inverters are not as expensive as 6kW inverters. There’s a much bigger range of 5kW single-phase inverters on the market (more choice, lower prices).
  • Some network distributors – like Powercor, Ergon and AusNet – won’t allow more than a 5kW inverter (but they’re OK with you getting the panels oversized by up to 133% of the inverter’s capacity, i.e. 5kW x 133% = 6.6kW)

6kW is a great size solar system for powering a battery (if you are thinking to the future, like that electric vehicle in your garage!)

Best value for your ‘solar dollar’

Overall, a solar system size of 6.6kW gives you more bang for your buck.  It is the new solar sweet spot for savvy householders looking to get the best value for their solar dollar. 

We can connect you with our trusted local installers, who will provide up to 3 FREE solar quotes for your home and business solar energy system. Here, you can also learn more about home and business solar panel system sizing. Get a quote today!

Our professional solar installers in Brisbane will assess and determine your energy needs. We customise a solar panel system in Brisbane to fit the roof size of your property, ensuring you receive the most suitable solar panel system for your Brisbane home, meeting to property’s energy requirements.

Get a quick solar quote, or contact us today toll free on 1800 EMATTERS or email our friendly team for expert, obligation-free advice!

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