What Size System?

Quick overview

The 1.5kW solar system makes up about half of all the solar systems ever sold in Australia. That’s because up until 2013, the maximum solar rebate you could receive was for a 1.5kW system. However, thanks to rebate changes, current rebates for solar systems don’t differ according to size. As a result, 1.5kW systems are less commonly installed now than five years ago.

That said, a 1.5kW solar system is still a sound investment. Perfect for a smaller household, it delivers great returns for energy efficient homes. Here’s everything you need to know.


Average cost

$2,490 to $3,200

Number of panels


Power generated

7 units/day

How much can I save?

Operating at full capacity, $105 per electricity bill cycle.

Average payback period

Within 5 years

Suited to

Smaller households with an electricity budget of $120 per bill cycle.

How much does it cost?

Prices for a quality 1.5kW solar system range from $2,490 to $3,200. Prices for a quality 6.66kW system range from $4,490 to $6,990 But it’s important to note that price is directly related to size and quality. Although you may find cheaper systems elsewhere, keeping within this price bracket ensures you’re buying a better quality product. And whichever system you purchase, you should also ensure it comes with a manufacturers warranty. If it doesn’t, it’s a sign the system’s of low quality and may not last the distance.

How big is it?

A 1.5kW solar system has 5 panels – perfect for smaller houses. Each panel measures around 1.6m x 1m, so you’ll need at least 10m2 of roof space. A 6.66kW solar system has 18 panels – perfect for 2-4 adults at home who want the peace of mind knowing that they can produce their own green energy during the day without having to pay for it.

How much power does it generate?

How many kWh is 1 unit?
1 kWh is the amount of energy consumption by 1 kW load in one hour. Therefore, 1 Unit = 1 kWh.
On average, a 1.5kW solar system generates 7 units per day. For the average household, this is enough for a third of your energy use. But if your home is highly energy efficient, a 1.5kW system can offset all your energy usage, while on average the 6.66kW system generates 27 units per day so depending on the average amount your household consumes per day will also determine the size system to install on your roof. As with every solar system, the amount of power generated depends on the amount of sun your location receives, as well as the positioning of your solar system. You’ll also generate more power in the summer months than in winter. But don’t worry, our installers will ensure your system’s positioned to receive as much sun as possible, all year round. Output also depends on the quality of your system. Higher quality systems operate better at higher temperatures and produce better results. So make sure you purchase the best quality panels and inverters you can afford – it’ll pay off in the long run.

How much can I save?

How much money you get back from your solar system depends on how much electricity your system exports, and how much you’re paid for it. However, operating at full capacity, a 1.5kW solar system will save you $105 per billing cycle, while the 6.6kW will save you over $300 per quarter with significant savings added up over time. And remember, the higher quality solar system you buy, the greater your returns will be and the more upfront STC’s Government rebate you’ll be entitled to save.

What’s the average payback period?

A good quality 1.5kW system will deliver a full return on investment within 5 years while upgrading to the 6.66kW payback period of only 3-4 years. Use more of your solar power during the daylight hours (and export less power to the grid), and you’ll pay it off in no time. And regardless of how long it takes to pay off your system, you’ll start saving on your electricity bills from day one – and isn’t that the whole point?

What kind of household does it suit best?

The 1.5kW system’s great for a smaller household. So if you’re a retired couple using power throughout the day with an electricity budget of $120 per bill cycle, this may be the perfect system for you. However, if you are looking to upgrade your old system installed over 7-10 years ago, then we highly recommend upgrading to at least a 6.66kW system that will negate your bill every billing cycle and add tax free  ($) credits to your next bill, all year round. We want you to get the most solar has to offer. That means choosing the right system for your needs. So give us a call on 1300 134 354 for a chat about which system best suits your lifestyle, budget and roof space.

To arrange a no obligation consultation at your home or office: