Selecting a quality solar panel from the hundreds of different models and many manufacturers can be a very difficult task. Here we provide a guide to choosing the best panels based on quality, efficiency, reliability, performance and return on investment. We also offer insight into the many innovations being used to improve performance, this is explained in detail in our solar technology guide.
For those not familiar with solar, read our introduction to solar panels here. In summary solar photovoltaic (PV) modules or simply solar panels have not changed much in basic function over the last 30-40 years. Virtually all solar panels still use a series of silicon cells to convert sunlight to DC electricity. What has changed dramatically is the efficiency of the cells and more so the huge cost reduction to manufacture panels, which has come down by over 80% since 2008.
In Australia the Clean Energy Council (CEC) has an approved database of solar panels which ensure that certified solar installers use modules which are fire rated and conform to the solar & electrical safety standards. See the CEC approved list of solar modules here
How to choose a quality Solar panel
Unlike solar inverters the biggest problem when comparing solar panels is they generally look very similar with nothing obvious to distinguish between high and low quality products. Unfortunately many solar installers and customers only have the glossy brochure to go by, which can easily baffle people with clever marketing and slogans. The common 'Tier 1' rating is also misleading and does not guarantee and panel is free from defects or will perform over the life of the system. This is why a manufacturers reputation and history are just as important as their perceived quality. Sunpower and LG energy are two manufacturers widely known as producing some of the highest quality solar modules with lowest degradation over time and best warranty conditions, however these panels also come at a premium price.
Since the Tier 1 rating can be misleading it is important to select a quality and reliable panel based on warranty details, test results and manufacturers service history.
Determining a quality panel is made difficult as it is not something which can be pulled apart and checked; panels can only be assessed using specialised equipment which highlight small faults or hot spots, but this can change once the panels are installed outside in the weather for a few years. The sun’s UV radiation and high summer temperatures create extreme conditions for any roof top mounted solar panel and it can take 5 years or longer before any potential quality issues become apparent. This is why the manufacturer’s warranty period, service history and reputation are essential to selecting a quality solar panel.
Solar PV technology is constantly evolving and many new panel technologies have only been on the market for a few years. Solar panels ‘should’ have a lifespan of 25+ years so it is vital to use a manufacturer which has both a solid reputation and likely to still be in operation in the future to backup any warranty issues.
The standard warranty period for solar panels sold in Australia and most of the world is a 10 year product warranty, also known as a manufacturers warranty, and 25 year performance warranty.
The product warranty protects the customer against defects which occur from both manufacturing issues plus component or material failures. This means the manufacturer must either replace or provide a refund for solar panels which fail within the product warranty period. In general solar PV manufacturers must provide the minimum 10 year product warranty but a growing number of premium manufacturers (highlighted below) offer 12, 15 or even 25 year product warranties.
The performance warranty also referred to as the 'power output warranty' ensures that the solar panel still produces a minimum power output after a specific amount of time.
Once installed outside and exposed to sunlight, UV radiation and weather all solar panels slowly reduce output power over time (usually less than 0.8% per year).
The industry standard is 80% power output retained after 25 years however some high-end panel manufacturers such as Sunpower and LG guarantee greater than 80% performance on most models after 25 years of use. There is also a growing number of manufacturers now offering 30 year warranties on the unique dual glass and bifacial solar modules.
Best Solar Panel Manufacturers
Here is our short list of the best quality and most reliable solar panel manufacturers supplying the Australian market based on company history, quality, real world performance and feedback from solar industry professionals. Here we provide a quick summary of the top manufacturers warranty conditions plus the most popular panels offering the best quality, efficiency, innovation and value.
See the full list here - Complete panel technology review
Sunpower is the world leader in high efficiency solar cells and offer the best power output warranty at 90% retained capacity after 25 years on the X series, plus a 25 year manfacturers warranty. Although the high performance IBC N-type cells used in Sunpower panels also come at a premium price and are not widely used in Australia. In north America Sunpower panels, the E series in particular, are very common and are one of the most popular and reliable panels available.
LG energy is generally regarded as the manufacturer with the best value range of high quality, reliable, high performance panels. As of May 2018 LG now offer both a 25 year manufacturers and performance warranty on the Neon 2 and Neon R modules which use the high grade N-type cells. LG's range of premium quality panels use several industry leading technologies with the Neon 2 panels using multi-wire busbars being one of the most popular panels in Australia.
Winaico is a relaively small volume manufacturer offering a premium range of panels which are very high quality but still reasonably priced. The Winaico M6 PERC panels come with a 15 year manufacturers warranty and are very well regarded and trusted by installers having a very good track record for long term reliability and performance in the harsh Australian conditions.
REC manufacture quality, cost effective panels which have proven to be very popular among installers, inparticular the TwinPeak 2 range of panels. TwinPeak were the first panels available using the half size cells, split module format providing in higher efficiency and improved shading tolerance.
Hanwha Q cells is a well known quality panel manufacturer which have an above average 12 year product warranty and improved long term performance of 83% after 25 years. The new Q.Peak Duo range of split cell modules are the latest innovation from Q cells with 6 bus-bars and up to 19.3% efficiency.
To round up the top six the well known Honey range of panels from Trina solar are considered great quality and very good value for money, in particular the Honey M (monocrystalline) panels.
Other notable manufacturers include Jinko, JA and Canadian Solar. A complete list of the top 10 panel manufacturers and the Australian made Tindo solar panels are listed along with a detailed breakdown of the latest solar cell technologies including PERC and bifacial.
Higher price equals higher Quality
Like most things, premium equipment also comes at a premium price. SunPower are considered the world leader but generally cost around 30% more than the competition. LG panels also come at a premium price but are more competitive on price and have a range of modules which are very well regarded and widely available which put them at the top of the list when it comes to both quality and value for money.
Why pay more? The additional cost for premium quality panels is $1200 - $1600 on a regular 5kW solar installation. This is not a lot extra for panels which would no doubt outperform and outlast cheaper panels by many years.
When considering Return On Investment (ROI) it is necessary to take into account performance and degradation rates over the life of the system. Lower cost solar panels will mean lower upfront costs and may perform well for many years but over time (usually 4-6 years) most high quality panels will still be operating closer to the maximum power rating which means higher energy yields and greater returns. After 20+ years the higher quality panels will no doubt be out performing low quality panels by 10% or more which is a considerable amount when you calculate this over the annual generation.
DNV GL - Independent Panel Testing
One of the world’s leading independent solar module testing and performance services DNV GL produce the annual 'PV Module Reliability Scorecard Report'. The 2018 PV module scorecard was just released in May 2018. Over the last few years most of our top rated solar panel manufacturers have consistently scored as a ‘Top performer’ among many of the world’s leading solar brands tested. A top performer does not mean they are ranked as number 1 but among the highest performing module’s in the group with no severe degradation or failures.
DNV GL is one of the world’s most reputable, independent solar PV testing companies and thus can provide a high level or confidence to the long term performance and reliability of solar modules for both large and small scale installations.
For more detailed information or solar module test results from numerous panel manufacturers it is recommended to refer to the annual PV Module Reliability Scorecard Report.
View the 2018 PV Module Reliability Scorecard Report here
Solar panels made in China
China is now considered one of the world leaders in crystalline silicon wafer and solar module manufacturing despite a poor reputation in the past. There are many reliable well established Chinese companies such as Jinko Solar and Trina Solar which are improving manufacturing quality, panel performance and spending big in research and development. Although there are still a few low quality panels coming out of China so ensure the company has a good track record before purchasing any unfamiliar brand.
Several leading solar module manufacturers with the majority based in China have formed the Silicon Module Super League (SMSL) including:
- Trina Solar
- Canadian Solar
- Hanwha Q cells
- JA Solar
- Jinko Solar
Together these companies manufacture around half the the worlds solar modules and hold many of the most recent efficiency records for the most efficient mono and poly crystalline cells.
Many big name solar manufacturers from Europe and the US have also moved manufacturing to places like China, Malaysia and the philippines over the years and as much of the process is actually automated the quality of products is extremely high, so long as you know which brands to choose. Q cells and Jinko Solar are particulary well regarded by many Australian installers.
LONGi Solar has recently emerged as the largest supplier of mono-crystalline silicon cells in the world and along with Jinko Solar is leading the push towards the next generation of high efficiency mono PERC panels.
Solar Panel Efficiency
The efficiency of a solar panel is a measure of the amount of solar irradiation which falls on an specific area and is converted into electricity. In real world use the efficiency (measured in %) is also dependent on a number of different external factors such as panel orientation, shading, dirt and cell temperature. A standard size 60 cell panel with 16-18% efficiency is usually rated at 270-290W where as a panel with higher efficiency cells of the same size can produce up to 340W using advanced cell technologies such as PERC and multi busbars.
Another comparison the amount of roof space required is much less for higher efficiency panels - For example 12 x high efficiency 360W solar panels such as those from LG or Sunpower with a 21% conversion efficiency can generate up to 1200W more power than the same number of lower efficiency 260W panels.
Efficiency of various silicon solar cells
- Polycrystalline - 15 to 18%
- Monocrystalline - 16 to 19%
- Polycrystalline PERC - 17 to 20%
- Monocrystalline PERC - 18 to 21%
- Monocrystalline N-type - 19 to 22%
The term efficiency is thrown around a lot but a slightly more efficient panel does not always equate to a better quality panel. Many people consider efficiency to be the most important criteria when selecting a solar panel but what matters more is the quality as explained earlier. Quality is related to real world performance, company history and manufacturers warranty conditions.
The Most efficient solar panels
The highest efficiency solar panels widely available anywhere in the world in 2018 are the premium N-type IBC models manufactured by SunPower and LG.
See full details in the solar panel technology review here.
All manufacturers produce a range of panels with different efficiency ratings depending on the silicon type used and whether they incorporate PERC or other cell technologies. Very efficient panels above 19% are generally much more expensive if cost is a major concern would be better suited to locations with limited mounting space available, otherwise you can pay a premium for the same power capacity which could be achieved by using 1 or 2 additional panels. However high efficiency panels are also generally very high quality and can outperform and outlast lower efficiency panels due to lower degradation rates, so the extra cost is usually well worth it.
Example a high efficiency 60 cell 330W panel could cost around $300-320 while more common 285W panels typically cost closer to $170-$180. With both made by the same manufacturer, this equates to roughly $0.60 per Watt compared to $0.90 per Watt. Although in the case of LG, Sunpower and Winaico, the more expensive panels have higher performance, lower degradation rates and generally come with a longer 'manufacturers' warranty period, so it is often a very wise investment.
Panel Size Vs Efficiency
Panel size is not always related to efficiency as larger size panels generally just incorporate more cells (ie. 72 cells per panel) to achieve greater power output. The two most common panel sizes are below: (rounded to nearest cm). Most residential installation use 60 cells panels while commercial and large scale solar farms use larger 72 cell panels.
- Medium : width 1.0m x length 1.65m (typical 60 cell)
- Large : width 1.0m x length 2.0m (typical 72 cell)
popular solar Panel Models
In addition to the best manufacturers there are a few models which were highlighted as favourites among our specialists and other Australian installers due to a combination of high quality, efficiency, performance and value for money.
LG NeON 2
LG Neon modules use double sided cells to absorb light from the front and the rear of the module similar to PERC* cells, along with the LG Cello thin wire busbar technology to further improve efficiency. As of May 2018 LG Neon 2 panels are covered by a higher 25 year product warranty and higher performance warranty of 86% after 25 years. LG panels also have frames with very high wind load ratings which make them one of the strongest panels on the market.
See full LG Neon 2 specifications here.
Winaico P6 PERC
The Winaico P6 PERC modules are highly regarded by installers due to the extremely high build quality, great service and 15 year manufacturers warranty. Winaico is a smaller manufacturer with a great reputation for reliability and performance supportedby the outstanding real world results at the Australian Desert Knowledge testing facility.
See full Winaico P6 specifications here
REC TwinPeak 2
REC panels use PERC* technology and a unique split configuration which divides the panel into two sections, upper and lower which combine at a centre mounted junction box. This creates a panel which is much more efficient when partially shaded. The half size cells also increase efficiency and performance under most conditions.
See full REC TwinPeak specifications here
Trina Solar Honey
The Trina Honey range of panels have been a favorite among installers for many years. They offer high quality and very good value for money from a large, trusted manufacturer together with good service. The recent Honey M plus range offer higher performance and efficiency over the standard Honey panels using monocrystalline (Mono PERC)* cells.
See full Trina Honey M plus specifications here
* Learn more about the various panel models and types here including PERC and the new bifacial panel technology.