Buying Solar Panels – What You Need To Know

Back in 2009, when SolarQuotes kicked off, solar panels cost a bomb: about 20 times more than what you’d pay today. This massive price drop means you can fill your roof with solar without stressing too much about the cost.

You don’t even need to stress about having your panels perfectly angled or facing the ideal direction. They’re such good value now that even if they’re facing south (which is the least ideal direction), they’ll still pay for themselves over time.

But, even though prices have plummeted, solar panel cost still matters. As with most things, you get what you pay for. Skimping on quality for rock-bottom prices is a no-go. Spending a bit more for reliable panels from a trusted brand, especially one that’s solid in Australia, is the smart move.

2. How Much Can You Save With The Solar Rebate?

Australia’s solar rebate, officially called the Small-scale Renewable Energy Scheme (SRES), takes a significant chunk off the cost of installing solar. How much? Around $300 per kilowatt of solar capacity. For a typical 6.6kW system, that’s about a $2K discount—and the best part? It’s applied upfront by your installer. No paperwork nightmares for you.

The rebate works by generating Small-scale Technology Certificates (STCs), which depend on your system size and location. Once you have determined those, you can calculate how many STCs you are eligible for with our solar rebate calculator. These certificates have a market value that fluctuates, and the scheme itself is set to gradually phase out by 2031, so it’s worth getting in sooner rather than later.

Still curious? We’ve broken it all down in plain English in our solar rebates page—check it out.

4. Specifications That Matter: Efficiency, Degradation, PMax

Solar panels have dozens of specifications. You can compare them on my solar panel comparison table. But as a consumer, I’d argue there are only three you need to know about:

Efficiency (%)

Efficiency measures the percentage of sunlight energy hitting a panel’s surface that is converted into electrical energy.  The higher, the better.  Today’s solar panels typically achieve efficiencies from 21% to 23%.

Why is high efficiency good? Well, the higher it is, the more watts of electricity you’ll get per square metre of panel, allowing a system to generate more energy from the same amount of roof space.  

So, if roof space is at a premium or you just want super-duper PV technology, look into higher-efficiency panels. The good news is that, in 2025, good budget solar panels will be as efficient as premium ones. A budget option like Jinko achieves an efficiency of 22.53%, which is comparable to premium brands like Winaico (23%), SunPower (22.80%) and REC (22.70%).

Degradation (% per year)

All solar panels become less efficient over time, but the rate of degradation varies. A budget panel may degrade at 0.5% per year, while premium panels like REC or SunPower degrade at about 0.25% per year. Over 20 years, this translates to:

• Budget panel: 10% efficiency loss (e.g., 22% drops to 19.8%).
• Premium panel: 5% efficiency loss (e.g., 22% drops to 20.9%).

While “double the degradation” sounds bad, in real terms, the difference in energy yield is only around 5% over 20 years.

If you value longevity and top performance, premium brands like REC and SunPower with lower degradation rates might be worth the investment. But if you’re budget-conscious, high-quality panels from brands like Trina and Jinko still provide excellent value, with minimal loss in energy output.

PMax Temperature Coefficient  (%/ºC)

Solar panels love light but hate heat because high temperatures reduce their efficiency. 

Temperature Coefficient of Pmax — or just Pmax — tells you by how much.  This will be around -0.35%/ºC for a typical panel.  The smaller this is, the better.  For every degree over 25ºC a panel’s output will be reduced by this percentage.

Phono panels provide the best Pmax at -0.24%/ºC.  If you live in a hot climate and want maximum energy on hot days, Pmax is worth considering. 

5. Solar Panel Warranties

Insist on at least a 25-year manufacturer’s warranty (also called product warranty) on the solar panels, which covers defects in workmanship and materials.

Pay particular attention to the fine print of warranty docs. Ideally, you’ll want a warranty that will replace defective panels and cover labour costs.  But the majority of warranties don’t promise this.  Avoid any that say the panels have to be sent away to make a claim.  Also, consider the history and experience of both the panel manufacturer and the company installing them.  Are they likely to still be around in 10 or 20 years if something goes wrong?

Finally, ensure the warranty isn’t tied to an expensive service contract. You don’t want to feel compelled to shell out $500 a year for a bloke to hose down your solar panels just to keep your warranty. By the way, this sort of warranty stipulation is likely unenforceable under Australian Consumer Law!

While Australian consumer law is strong and can require companies to provide support they don’t include in their warranties, it’s always good to have a warranty that promises comprehensive support, as you are less likely to have to fight to get it.

6. Country Of Origin: Are Chinese Panels Crap?

Some people insist the best solar panels are made in Germany, and all Chinese solar panels are crap. Follow that previous link for a deeper discussion on this, but I find that talk borderline xenophobic.

You may have Pauline Hanson-style reasons for not buying Chinese products. However, as far as quality is concerned, many Chinese brands are world-class. Some are crap, but if you think “Chinese” is synonymous with “low quality”, what do you think about your iPhone, Macbook Pro, or Tesla Model 3?  Yep, made in China …and they’re all high-quality, sophisticated devices.

7. How Green Are Solar Panels?

Solar panels provide a huge environmental benefit over burning fossil fuels by generating energy from sunlight.  But do some provide more benefit than others?  The answer is yes.  But, provided they are reliable, the difference is very small compared to the drawback of not having solar.

If your goal is the lowest greenhouse gas emissions possible from your solar, I recommend looking at the following:

1. Do the panels have a reputation for reliability and a long manufacturer’s warranty?  The largest waste of solar resources occurs when cheap and shoddy panels have to be replaced after only years of use rather than multiple decades.
2. Are the panels high-efficiency?  These require less material per watt of panel capacity and so, all else equal, result in lower emissions from manufacturing and transport.
3. The manufacturer’s own claims about emission reductions.  Some companies are more committed to cuts than others.   

Solar panels can also be recycled.  While still in its early days in Australia, panels can be recycled in Europe with a 95% material recovery rate.  If you want easier and safer-to-recycle panels, you can pay extra for lead-free ones.  REC is the only company currently producing these, but other manufacturers may follow.

Some people prefer the look of certain types of solar panels to others — this is just down to personal preference.  For standard panels, the main choices are:

• Silver frames.
• Black frames
• All black panels

Because they get a little hotter, all black panels have slightly worse performance than otherwise identical ones.  But the difference is very minor. 

Some suppliers can integrate the panels into your roof; others can supply solar roof tiles. And if you’ve got a whacky, curved roof, you can even get flexible solar panels! However, the sleek aesthetics of building-integrated solar power (BIPV) come at a price, of course.

Generally, choosing a more “utilitarian” look will be cheaper as super slick integrated systems can cost considerably more. But first, check how visible your solar panels will be from the ground.  There’s no point in paying for ones that look good if no one ever sees them.

9. The Best Solar Panels In 2025

Here are the brands I currently recommend. You can find reviews from Australian owners of all these brands (and others) in my solar panel reviews section.

I also asked installers in the SolarQuotes network for their recommendations – what they would install on their own rooftops? Discover what they voted the best solar panels in 2025. You’ll notice all the brands installers voted the best also appear on the chart above.

Conclusion

Consider the following when choosing solar panels:

• System Size: Fill your roof with as many panels as possible for maximum year-round energy.
• Efficiency: Most panels are 21–23% efficient. In hot climates, choose panels with a better temperature coefficient (Pmax) to reduce energy loss.
• Degradation: Budget panels degrade faster (0.5% per year vs. 0.25% for premium ones), but the difference in energy yield over 20 years is minimal (~5%).
• Temperature Coefficient (PMAX): If hot weather performance is important to you, look for a PMAX close to -0.25%/ºC. Budget panels will be closer to -0.35%/ºC.
• Budget vs. Premium: Budget brands like Jinko and Trina are great value; premium brands like REC and SunPower last longer and perform better in tough conditions.
• Installer and Warranty: A trusted local installer and strong warranties are crucial for long-term reliability.

Focus on these points, and you’ll enjoy clean, reliable energy for decades.

FAQs

How many solar panels do I need to run my house in Australia?

Firstly, a simple number of panels is not a good guide for system size. Read why in the next FAQ.

• Australian houses normally use between 16 and 20 kilowatt hours per day.
• A solar array rated at 1 kilowatt (peak capacity) will generate around 4 kilowatt hours per day.
• Simple maths says the average house will only need 4 or 5 kilowatts of solar. However, modern systems are seldom less than 6.6kW unless space is constrained.
• When sizing a solar power system, it’s worth considering that winter is generally the time of high electricity demand and low solar yield.
• The best system available is generally the biggest one you can install on your roof.
• Excess yield is actually a feature, not a bug. If solar export tariffs become a potential penalty, this is easily solved with battery storage, hot water heating or an export limit.
• Off-grid houses normally require significantly larger solar power systems (unless they’re exceptionally efficient passive solar designs).

How many panels are in a 6.6 kW solar system?

As solar technology progresses, not only do panels become more efficient in terms of space, they are also getting physically bigger. Rated output has risen to a point where panels are around half a kilowatt per module.

As of early 2025, leading panels are commonly 470 watts each, and around 2.1m² so for this size; 14 panels are needed to make up a 6.6kW system

They will cover at least 29.5 m² with an area efficiency of approximately 223 watts per square metre.

For context, a system sold by Solar Shop around 2008 may have used “thin film” panels, rated at only 60 watts and 1m² in size. Systems were commonly only 1kW in total and used 16 panels. A 6.6kW system was almost unheard of and would require 110 panels.

The simple number of panels isn’t a good measure of system size or efficiency.

How many solar panels do you need to run a house?

How long is a piece of string? Again, a simple number of panels is not a good guide for system size. The rated output of panels has risen over the years so depending on when you asked this question, the answer can vary. Read our previous FAQ for a better understanding.

Is it still worth getting solar panels in Australia?

YES. Solar power is great value. Solar offers a return on investment that is so good, you’d hardly think it’s legal. It might sound like hyperbole but Scott Pape, The Barefoot Investor, is embarrassed he didn’t do it sooner.

If you’re ready to get pricing on a system, you can get up to 3 solar quotes via my service from Australian installers I have personally pre-vetted and trust that I will match to your requirements and location.

>> Next: What Types Of Solar PV Panels Are There To Choose From? >>