ETFE is a groundbreaking thin-film plastic material opening up new innovative ways to use high strength plastics.
While it was invented in the 1970s, it was not until the 21st century that its full capabilities were unleashed on the world.
The initial development was as a lightweight protective film for aerospace but now it is used in many amazing cases on Earth.
In fact, the Eden Project became the first large-scale project to incorporate the material thanks to its super strength and ability to control solar conditions.
Now it is used in many iconic buildings and to build lightweight yet durable solar panels.
The features that make it ideal for spacecraft and giant greenhouses, also create the ideal conditions for solar panels.
If you’re interested in ETFE solar panels then you’re in the right place.
Keep reading to find out everything about ETFE solar panels including the best products available today.
What is an ETFE Solar Panel?
An ETFE solar panel is built using ultra thin solar cells, EVA foil, backsheet, and ETFE plastic. In simple terms, it is a flexible solar panel wrapped in ETFE plastic film.
ETFE is an acronym for ‘Ethylene tetrafluoroethylene’ which is a super strong and lightweight plastic film.
Due to its unique properties, it is perfect for use to protect flexible solar panels.
There are a huge number of benefits to using ETFE in solar products which include:
Self Cleaning – It has a non-stick surface which means dirt and dust doesn’t build up on the surface. This helps to keep solar panel efficiency high as it reduces dirt blocking sunlight hitting the solar cells.
Super Strong – As it was invented for aerospace, it is incredibly strong. It has a tensile strength of 42MPa or 6100PSI. That means it can withstand adverse weather such as wind, snow, snow and rain. Although, it is still susceptible to puncture from sharp objects such as knives.
Lightweight – ETFE is a plastic film which means it is very lightweight. It is over 90% lighter than the glass in a traditional solar panel. Adding to this, it is incredibly thin to further reduce the size of a solar panel. In fact, an ETFE solar panel is more than 70% lighter overall.
Durable – It is an incredibly long lasting material, even when exposed to the elements. You could expect an ETFE solar panel to last well over a decade. It’s so durable that it is used in roofing for commercial buildings including football stadiums and train stations.
Light Transmission – This is a key property that ensures plenty of sunlight gets through the covering and hits the solar cells. It has a light transmission rate of 95% which is as good as any window.
High Melting Temperature – ETFE is often favored for wrapping electronic circuits and wires because of its high melting temperature. It means it can withstand heat up to 300 °F. That means it can cope with direct sunlight or any electrical faults without catching fire.
Waterproof – As you might imagine it is completely waterproof which is critical for solar panels. You want to keep water out of your solar cells. This means ETFE solar panels are perfectly ok to be mounted outside permanently.
Are ETFE Solar Panels Any Good?
As you can see from the benefits of ETFE solar panels listed above, they are one of the most popular types of equipment.
They are particularly good for using on vehicles such as boats, vans, and RVs. The unique blend of properties allows vehicle owners to save weight while receiving brilliant performance.
To be honest, the performance of an ETFE solar panel is equal to a traditional rigid frame product. You’ll still generate electricity with monocrystalline solar cells at a conversion efficiency of over 21%.
Adding to this, the thin film plastic covering means they are flexible. This is a huge bonus as it allows you to mount them on uneven or curved surfaces. Once again, this is a benefit to vehicle owners with odd shaped roofs. Plus, people have been known to stitch them into fabrics, life tents, and canvas.
Is ETFE Better Than PET?
Yes, ETFE is better for use on solar panels than PET covering. PET is still widely used for flexible solar panels as it is 60% cheaper to manufacture.
While ETFE solar panels are more expensive, you gain significant performance increases. For example, ETFE transmits 95% of light whereas PET only has 80% light transmission.
In addition, its self-cleaning properties help to ensure transparency for the length of its life cycle. Contrastingly, PET solar panels will require more diligent cleaning and develop permanent dirty markings during prolonged usage.
Finally, if you’re conscious of the environment then you’ll be pleased to know that ETFE is miles better than PET. To start with it is completely recyclable, so when you’re finished with the equipment you can strip out the plastic and recycle it. Even the production of ETFE is less damaging as it doesn’t require harmful Ozone destroying chemicals.
ETFE vs PET Solar Panel Performance
| Material | ETFE (Ethylene Tetrafluoroethylene) | PET (Polyethylene terephthalate) |
| Thickness (mm) | Less than 0.1mm. Includes a UV protective layer. | 0.15mm |
| Light transmission | 95% transparency to let the majority of light through to solar cells. | 80% to 90% which means it allows less light photons through to solar cells. |
| Outer surface | Anti-adhesion so dirt and dust won’t stick to it and can be cleaned easily by rain. Self-cleaning. | Adhesive surface which dirt and dust stick too. This reduces performance if left uncleaned. |
| Durability | Over 10 years. Very durable material unless punctured by sharps. | 5 years as it starts to peel allowing air and moisture inside. |
| Corrosion | Anti-corrosive to deal with salt water and bad weather. | Not resistant to acid or alkali so not good for boats and marine use. |
| Temperature | No problems with high or low temperatures. Flame retardant and high melting point of over 300°F | Suffers in hot climates. |
| Reflectiveness | Non-reflective surface which helps to absorb maximum sunlight. | Products glare and reflections. Sunlight can bounce off it away from solar cells. |
How Long Do ETFE Solar Panels Last?
ETFE solar panels should last at least 10 years even when mounted outside and exposed to the elements. This is shorter than a traditional rigid solar panel but is still brilliant durability for the price and performance.
You will still need to treat them very carefully, especially when installing and carrying out maintenance such as cleaning. Although the ETFE is very strong it can easily be punctured by a sharp object. This will quickly allow air and moisture inside the panel and speed up degradation. Plus, you should avoid walking on them as this will cause damage and microcracking to your solar cells.
Can You Walk on ETFE Solar Panels?
No you should not try to walk on ETFE solar panels unless otherwise instructed by the manufacturer. Generally, they will not cope with human footsteps as it can cause cracking to the solar cells.
Some marine ETFE solar panels can be walked on occasionally but check the manufacturer information before trying this. In addition, when wet the surface becomes very slippery. You should not use ETFE solar panels as flooring or in high traffic areas.
Is ETFE Waterproof?
Yes, ETFE solar panels are completely waterproof. As long as there are no holes or punctures in the film then water will not get through. They are also resistant to salt, acidic, and alkaline solutions you find in seawater which makes them popular on boats.
Final Thoughts on ETFE Solar Panels
So you should have a good idea of whether ETFE solar panels are right for you.
If you’re looking for a durable flexible solar panel then it will be the best option, especially on a vehicle like a boat or van. Despite being more expensive than PET the performance and life cycle is much better. You’ll get more electricity for years longer!
Adding to this, flexible solar panels are incredibly easy to install and transport. You can even glue or velcro them into place. Plus hang them from walls or stitch into fabric.
On the other hand, if you’re looking for solar panels for your house then it will be best to look at more traditional aluminum and tempered glass solar panels. These are more expensive but last more than 25 years to give you an increased return on your investment.
So are ETFE solar panels any good? The answer is a resounding yes!
