Comparison of good and bad lightweight flexible solar panels
Facts you MUST know before buying flexible solar panels for caravan or boat
Just because a website claims they have the 'best' solar panels does not mean you will get quality products and accurate information so 'Buyer Beware'! Avoid the pitfalls when buying flexible solar panels so you are not disappointed after your purchase.
The owner of Solar 4 RVs is committed to providing accurate and honest information and undertakes extensive research and testing. He is a highly qualified and experienced electrical/electronics engineer with over 30 years experience as a marine engineer and systems engineer working on some of Australia's largest and most complex defence projects. Read his bio here
It is in our best interest that both the public and businesses have a positive experience with flexible solar panels, and that will only happen if customers are happy with their purchase.
There are many claims about flexible solar panels and it can be difficult for a consumer to know what is accurate and what is misleading. This guide aims to assist you in your decision making so you can make an informed choice. You want your purchase to meet your expectations and provide value for money.
Are you only comparing prices?
The price can be a good indicator of the quaity of the panels. If the price is too good to be true then it probably is too good to be true!
We constantly receive many ‘proposals’ from Chinese manufacturers that offer ‘cheap’ panels. This can be very tempting for sellers of solar panels as it means they can achieve a better profit margin. However, you get what you pay for so customers need to balance the risk of buying cheaper flexible solar panels against the purchase price.
Flexible solar panels can be offered by Chinese manufacturers at a cheap price because they are mass produced in large production runs with low cost cells and materials and minimal quality control checkpoints.
Possible issues that could be encountered when purchasing cheap flexible solar panels:
- overlapping cells;
- damaged cells;
- inferior cells (are you really getting SunPower cells? see information below);
- sharp edges;
- inadequately sealed junction boxes allowing corrosion from water, particularly sea water;
- zinc plated fixings in the junction box which corrode with moisture;
- inferior by-pass diodes fitted or not fitted at all.
It's not WHERE they are made that is important - it is HOW they are made
The majority of flexible solar panels are made in China even if the seller doesn't declare this and refers to 'cells' as being made in the US. There are many manufacturers in China and they produce various grades of solar panels and then on-sell them through pro-active marketing campaigns and email cold-calling.
If a supplier carries small quantities of stock they are unlikely to have been manufactured in separate production runs to specific quality requirements. They will probably be off-the-shelf stock.
Solar 4 RVs does not purchase unknown ‘grades’ of panels and in fact we do not purchase any panels from standard manufacturing runs. Our RADpower flexible solar panels are made in separate production runs by our trusted manufacturer in China to our strict specifications using genuine A grade MAXEON GEN II and GEN III SunPower cells.
Checks undertaken during the manufacturing process are extremely important. RADpower flexible solar panels are all tested during production. Solar 4 RVs has visited their Chinese manufacturer in Shenzhen to observe the manufacturing process, view the testing, and meet with managers and factory personnel to discuss quallity control and the latest technologies and equipment.
Flexible solar panel testing during production
During production all our RADpower panels are subjected to testing:
• Electrical testing, i.e. voltage and current; plus
• Electroluminescence (EL) testing.
The electrical test confirms the current and voltage are within production limits while the EL test confirms that the cells are free of defects and are well matched. If present these result in a lower panel output and possibly a shortened lifespan.
During the EL test a current is passed through the panel which turns part of the current into short-wave infra-red (SWIR) light at a wavelength of around 1150nm, i.e. the panel will “glow” with invisible infra-red light. A photo of the “glowing” panel taken by a special camera will show up micro-cracks or other defects in the cells and any significant mismatch between cells.
These issues are only visible with this EL test. The first of the following three images show a very poor quality panel with many defective cells. The second image shows up significant mismatches between cells, i.e. the intensity of the glow is related to the efficiency with which the cell will convert sunlight into electricity. The third image shows a panel free of cell defects and with only small variations in cell efficiency.
Are you really getting genuine SunPower cells in your flexible solar panel?
SunPower is one of the largest suppliers of quality solar cells in the world with a reputation for producing the highest efficiency cells. They are widely used in rigid, framed, glass topped solar panels for residential and commercial settings.
At around 22% SunPower cells have one of the highest efficiency of any available cell on the market. A solar panel assembled from these cells has an overall efficiency around the 20%, with the 2% loss being attributable to the inter-connections and the slight opacity of the top layers. We have seen some websites claim efficiencies of 22% for a panel, but this is an exaggeration.
In the past, SunPower sold their cells to an unlimited number of manufacturers who used them to make flexible solar panels. SunPower has now ceased this practice to ensure the cells are only used in quality products. Only two manufacturers in China now have access to SunPower cells. Our manufacturer has certification from SunPower that confirms they obtain geniune SunPower cells.
Many flexible solar panels sellers state their product has SunPower cells. How can you tell?
- The SunPower company provides certification to the manufacturer when they supply them with SunPower cells. Even if their manufacturer does have certification it doesn't necessarily mean all their panels are manufactured using SunPower cells. This is because manufacturers make and sell different grades of solar panels at different price levels depending on quality.
- The SunPower company limits the size of flexible solar panels manufactured using their cells to 150W. The failure rates for larger panels increases due to mechanical and thermal stresses on the panel. If you see larger sizes of flexible solar panels claiming they have SunPower cells then questions about the accuracy of the claims need to be raised.
- SunPower cells are expensive to buy and manufacturers need to pass on these costs so if a flexible solar panel is very cheap then it is highly unlikely they contain genuine Sunpower cells.
Not all lightweight flexible solar panels are the same
What materials are used in manufacture? Does the supplier clearly outline what cells are used and the encapsulation?
Our RADpower flexible solar panels are made with the latest technology. We constantly undertake research testing to stay at the forefront of improvements.
Our RADpower Premium and PremiumPlus panels have an ETFE top surface.
ETFE (Ethylene-Tetra-Fluoro-Ethylene) is a high-strength fluorine polymer that is corrosion and stain resistant, non-stick self cleaning, and retains its clarity (and therefore light transmittance) ensuring long service life for solar panels. It will not discolour or degrade from exposure to environmental pollution, UV light, harsh chemicals or extreme temperature variations. The surface is textured for extra robustness.
Accreditations, certifications and standards - don't be misled
ISO9001 Quality Accreditation
Our RADpower flexible solar panel manufacturer is accredited with the ISO9001 quality management system.
According to ISO9001, “This standard is based on a number of quality management principles including a strong customer focus, the motivation and implication of top management, the process approach and continual improvement." Using ISO 9001 helps ensure consistent, good quality products and services so we are confident our manufacturer is quality focussed.
However, a quality focus with policies, procedures and documents in place does not realistically ensure every product off a production line will be of high quality. Customers need to be be aware that it is a good indicator of quality but it is not a checklist for product quality or an endorsement of the quality of a particular product.
Australian and International Standards
The international standard for performance testing of crystalline (both mono and poly crystalline) PV panels is IEC-61215. Certification to IEC-61215 is a pre-requisite for PV panels to be used in residential applications in Australia, but is NOT for PV panels on other structures such as caravans and boats.
The primary standard covering solar panels in Australia is AUS/NZ 5033 Installation and safety requirements for photovoltaic (PV) arrays which references several international standards covering testing and certification of solar panels. Subject to the specifics in the standards, panels that are installed onto buildings and ground installations must be certified to the standards, and in addition, for the Renewable Energy Certificates (RECs) the panels must also be listed in the Clean Energy Council (CEC) register of certified panels.
Generally, for panels installed into mobile situations the panels do not need the certifications as mentioned in AUS/NZ 5033, however all products must still conform to all the overarching standards that apply in order for a product to be sold in Australia. These are similar to the requirements for CE marking in Europe.
If a company claims that their flexible solar panels conform to the Australia Standard then it would be pertinent to investgate further into the credibiity of their claims.
Our panels carry the CE Mark which is a mandatory mark for certain product groups, including solar panels and electronic products, in order for them to be sold in the European market. The requirements are set out in European Directives (similar to Australia’s Regulations and Acts) that cover health, safety and environmental protection legislation.
The use of the CE mark, indicates self-certification by the manufacturer that the device meets the minimum European Union requirements for Electro Magnetic Compatibility (EMC) compliance.
The CE mark has nothing to do with the quality, performance and longevity of the panel. CE is the abbreviation for the French phrase "Conformité Européene", i.e. in English "European Conformity".
Warranties - will they be honoured?
Is there is only mobile phone contact? Sellers of flexible solar panels without any infrastructure or bricks and mortar can easily shut down when warranty claims for cheap panels become an issue.
Who can you trust?
Anyone can set-up a website and claim they are experts or leaders in the field, even if they are unqualified and selling a few panels out of the garage, but do they really have the knowledge required. With flexible solar panels becoming popular there are many people starting up webshops to sell them online.
Solar 4 RVs is a multi-award-winning company that is publicly acknowledged as the leader in solar systems for mobile applications including caravans and boats. The family business operates across Australia, New Zealand and the South Pacific from their showroom, warehouse and offices in the Melbourne suburb of Rowville. The premises also has a workshop with testing facilities.
Solar 4 RVs stocks the largest range of flexible panels in Australia including our own RADpower brand and we are the Australia, New Zealand importer of the Italian Solbian brand. eArche thin lightweight panels are our latest addition with an amazing 10 year product warranty. We supply well over 300 businesses including government departments as well as the public.
We receive many phone calls from consumers wanting to buy our premium solar panels after being disappointed with solar panels purchased elsewhere.
They realise too late that it is worth spending that little more to obtain a quality product in the first instance. When things go wrong, they end up spending a great deal more by having to replace their original purchase.
Don't believe everything you read and make sure you are confident that the business you choose will supply a quality product, honour an appropriate warranty and is knowledgeable enough to provide accurate and honest advice and support before, during an after your purchase.
Scope of this report
This report refers to flexible solar panels made in China. It does not refer to the Solbian brand of SolbianFlex solar panels which are made in Italy and is the trusted brand of yacht racers. We are the authorised importer of Solbian panels in Australian/NZ and distribute to the public and businesses that sell Solbian flexible panels. Our own brand of RADpower flexible solar panels are made in China.