Bearing in mind that the useful life of a solar panel is around 25 to 30 years, the time is approaching to ask ourselves what happens to used solar panels when they expire, when they reach the end of their useful life.
Solar energy is experiencing massive growth, and with millions of installations carried out in recent years, a major challenge is beginning to emerge: the end of life management of solar panels. Little by little it loses performance, it reaches a point where it is no longer profitable… and that is when we ask ourselves what to do with them. Let us see what you can do.
What is done with solar panels after their useful life?
Upon reaching the end of their useful life (25-30 years), their performance has usually dropped enough so that energy production is no longer profitable.
But beware, useful life does not mean that the panel becomes unusable, only that it no longer works at the expected level. Therefore, these panels can follow different paths: recycling, reuse or even sale in second hand markets, although we do not advise the latter. Let us look at each one.
1. Recycling
Recycling is, by far, the most responsible option and the one with the most future. And not only for environmental reasons, but also for economic reasons. Solar panels are composed mainly of glass (between 70% and 75% of the total weight), aluminum, silicon, copper, silver (in small amounts) and encapsulants and plastics.
The good news is that more than 90% of a solar panel can be recycled with current technology. In fact, the European Union requires them to be recycled under the WEEE directive (Waste Electrical and Electronic Equipment). The process is usually this:
- Aluminum frame separation. The frame is removed, which is fully recyclable.
- Crushing the panel. The glass and other elements are separated by densities.
- Silicon recovery. This process allows recovering solar cells or refined silicon to manufacture new products.
- Extraction of valuable metals. Such as silver or copper present in the panel.
In addition, new technologies are being developed that will allow recycling almost 100% of the panel and recovering even materials that today are lost or processed less efficiently, so recycling used solar panels, besides being possible, is necessary.
2. Reuse for specific uses
If these 30 years have not passed, a used solar panel is still useful, although not at the level necessary for a modern domestic or industrial installation. Therefore, if a panel retains at least 70% of its initial capacity, it can be reused for lower demand applications. If it drops below that threshold, it is no longer useful for most projects, not even as a cheap solar panel.
If they have that 70% they can be used for:
- Water pumping systems for small orchards
- Educational projects
- Experimental installations
- Low power lighting in shelters, sheds or huts
- Portable emergency systems
- Low consumption electronics (sensors, weather stations, etc.)
The problem is that performance is not the only thing that matters. Degradation also affects the voltage, internal resistance and thermal stability of the panel. Therefore, not just any used solar panel is valid for reuse, even if it retains an acceptable percentage of generation.
3. Second hand market (not recommended)
There is a second hand solar panel market, but here we must be very clear, it is not a recommended option for most people. To begin with, the internal state of the panel cannot be guaranteed, a panel can look good on the outside and be completely degraded on the inside.
You also do not know how many thermal cycles it has endured and the fact is that the sun, humidity, wind and temperature changes degrade the materials. In addition, the real performance is never the one indicated by the seller and the technical sheet values are no longer valid, they are obsolete. Of course, they do not usually have a warranty neither from the manufacturer, nor from the seller. And if they do, it rarely covers anything useful.
Sometimes there is a hidden cost in structures, cables and inverters, so even if the panel is cheap, the rest of the system must be adapted to it. Being second hand, the remaining useful life for you will also be less, so you would amortize it much less. It is also not economically profitable, the initial savings do not compensate for the low production.
Furthermore, many panels are sold on platforms or warehouses as demolition stock or coming from retired industrial installations, but the true reason for their withdrawal is not reported, or even sometimes it can be a scam. In practice, the used solar panel market is a terrain where people usually lose money.
Why you should not buy second hand solar panels
1. Real efficiency is much lower than expected
If a panel has already lost 30% or 40% of its capacity, you will need more panels to achieve the same production as a new one. That is, you buy cheap, but you pay dearly in performance.
2. The installation can be more expensive
Old panels may require more surface area, adapted structures, different cables, a compatible inverter and more labor. In the end, what you save on the panel you spend on everything else.
3. You will not have a warranty
A new panel usually has:
- 10 to 12 years of product warranty
- 25 years of performance warranty
A used panel does not, so if it breaks, you lose the entire investment. Therefore no, it is not worth buying used solar panels except in very specific cases (experimental projects, non critical or educational uses).
How is the recycling of used solar panels
The recycling process is advancing very fast thanks to regulation and market pressure to make it more sustainable. Recycling is divided into several steps:
- Collection and logistics. Specialized companies collect the panels in domestic installations, solar plants and authorized collection centers, classifying them beforehand by condition and type (monocrystalline, polycrystalline, thin film).
- Separation of components: first frames, cables and junction boxes are removed.
- Crushing. The panel is fragmented with specialized machinery.
- Density separation. The glass is separated from the rest by vibration, air or water.
- Thermal recovery. The materials are heated to separate polymers and make the internal layers accessible.
- Extraction of metals and silicon, recovering aluminum, copper, and silver.
- Reintegration into the industry. Recycled glass can be reused in new technological products, insulation, construction and manufacturing of new solar panels (in certain cases).
The most important thing about all this is that Spain and Europe are developing specific plants for this type of recycling, which will allow it to be even more efficient and profitable in a few years.
Can I get money for my old solar panels?
In some cases you can get money for your used solar panels, although it will depend on their condition and the value of their materials. There are 3 main ways.
1. Companies that pay for recycling
Some companies cover the transport and pay a small amount for recyclable materials (especially aluminum, glass and silicon). It is not a large amount, but it can compensate a part of the removal.
2. Sale to second life projects
If your panels still have a performance greater than 70%, they may be of interest for experimental installations, universities, makers and creators of electronics and low power systems. The price will not be high, but it can be more profitable than recycling them directly.
3. Social projects
Some NGOs reuse panels to electrify rural shelters, urban gardens and cooperation projects. Many of these organizations offer a symbolic economic compensation.
Used solar panels are generating a new scenario within the renewable energy sector. Their correct management is essential so that solar energy continues to be truly sustainable in all its stages. Solar energy is entering a new phase where not only what the panels generate matters, but also how they end their life cycle. And that is good news: it means that the industry is evolving towards a more circular, efficient and sustainable model.
