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 high electrical safety standards. See the CEC approved list of solar modules here
How to choose a quality 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 around the world is a 10 year product warranty and 25 year performance warranty.
The product warranty is the manufacturers warranty for defects which means the manufacturer must either replace, repair or provide a refund for panels which fail within the product warranty period. Manufacturers must provide the minimum 10 year product warranty but several premium manufacturers highlighted below offer 15 or even 25 year product warranties.
The performance warranty also known as a 'power output warranty' ensures that the panel still produces a minimum amount of power after a certain amount of time. The industry standard is 80% power output retained after 25 years - this equates to a common 275W panel still generating close to 220W after 25 years of use (in ideal conditions).
Some high-end panel manufacturers such as Sunpower and LG guarantee greater than 80% performance on most models after 25 years of use, and a growing number of manufacturers are offering 30 year warranties on the new generation dual glass and bifacial solar modules.
High Quality Solar Panel Manufacturers
Here is our short list of the most reliable solar panels available on the Australian market based on manufacturers history, quality, real world performance and feedback from solar industry professionals.
Other notable manufacturers include Jinko Solar, Hanwha Q-cells and Canadian Solar. A complete list of the top 10 panel manufacturers and the Australian made Tindo solar panels are listed here along with a detailed breakdown of the latest solar cell technologies including PERC and bifacial modules.
Several panel manufacturers really stand out in terms of quality and performance. Sunpower still offer the best power output warranty at close to 90% after 25 years plus a 25 year manfacturers warranty, although they do come at a premium price and not widely used in Australia. LG also offer a 25 year manufacturers warranty for their premium Neon R models and produce a range of high quality panels with industry leading technology, in particular the LG Neon 2 model being a common favorite. Winaico has also moved up the ranks with their M6 PERC range offering a 15 year manufacturers warranty and being well regarded by installers. REC solar panels are great quality and very popular among installers, inparticular the unique TwinPeaks range of panels. Finally, to round up the top five the well known Honey range of panels from Trina solar are considered great quality and very good value for money.
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 they have many more competitive models which are very well regarded and widely available which put them at the top of the list.
Why pay more? The additional cost for high quality panels is around $1000 on a regular 4kW solar installation. This is not a lot extra for panels which would no doubt outperform and outlast cheaper panels by many years.
Industry Recommended solar Panels
In addition to the best manufacturer's there are a few models which were highlighted as favourite's among 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. LG Neon panels are covered by a 12 year product warranty and higher performance warranty of 84.8% after 25 years. They also have one of the highest wind load ratings and are one of the strongest panels on the market. See full 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 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 spece 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 specifications here
* Learn more about the various panel models and types here including PERC and the new bifacial panel technology.
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 including Trina Solar, Canadian Solar, Hanwha Q cells, JA Solar, Jinko Solar and Longi. 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. Trina Solar 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 to next generation high efficiency mono PERC panels.
For more detailed information or solar module test results from numerous panel manufacturers it is recommended to refer to the renowned testing facility DNV GL an international accredited registrar and classification society headquartered near Oslo, Norway.
High Efficiency solar panels
The efficiency of a solar panel is a measure of the amount of solar irradiation which falls on a panel 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 temperature. A standard size panel of 16% efficiency is usually rated at around 260-270W where as a highly efficient panel of the same size can produce up to 340W. Another comparison is of a solar panel with 20% efficiency (on a sunny day at noon) positioned at the wrong orientation or at high ambient temperature can operate as low as 14% efficiency, depending on the conditions.
The term efficiency is thrown around a lot but a 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.
Efficiency of various silicon solar Panels
- Polycrystalline - 15 to 18%
- Monocrystalline - 16 to 19%
- Polycrystalline PERC - 17 to 20%
- Monocrystalline PERC - 18 to 21%
- Monocrystalline N-type - 19 to 22%
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 more expensive so 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 often worth it.
For 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)
Investing in Quality
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 5-8 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 add this over the annual output.