A Buyer’s Guide For Used Solar Panels

Is there a market for used solar panels? You would be surprised. The adage ‘one person’s trash is another man’s treasure’ holds true for used solar panels too.

There is a thriving market for them in America and many other parts of the world. Solar energy contributes to 3.4% of total U.S. electricity generation.

The demand for used solar panels comes from resellers or exporters, from individual buyers looking for cheaper second-hand panels, and from those who practice off-grid living. When times are hard, people favor used solar panels over brand-new ones even more.

The problem with used solar panels for sale is the risk of buying damaged goods. However, taking the right precautionary steps will help reduce this risk.

In this article, we explain why there is still value in used solar panels and what you should look out for when purchasing them.

What is a used solar panel?

A used solar panel is a photovoltaic (PV) panel that has been previously installed on a solar array system and removed for resale or reuse. Used solar panels may come from solar arrays that were uninstalled due to system upgrades, damage, or the closure of a solar farm.

Therefore, any panel that was previously owned by any other person, company, or any other entity, is a used solar panel. Even if someone has never used them but taken them out of the box, we still consider them used. Given that solar panels have a life spanning around 30 years, any panel used for approximately 15 years is also considered ‘used.’

‘Used’ can be perceived differently because not all solar panels are equal, and the longer lifespan depends on their maintenance and the buyer’s judgement. Nevertheless, finding a good quality used solar panel is not very difficult irrespective of where you stay, but you need to be patient and set realistic standards in finding the right product for your use case.

Refurbished vs. used solar panels

You already know that used solar panels have previously been taken out of the box and used for a considerable time (maybe). Refurbished solar panels are solar panels that were formerly used (not for long) but have been restored to an acceptable condition fit for usage by a professional refurbisher or manufacturer.

So, used solar panels are unlikely to perform as new, and buyer expects degraded performance in some form. In contrast, while refurbished ones may not last as long as new ones, they operate like new ones because some parts of them may have been restored or replaced professionally.

What is the value of a used solar panel?

The value of a used solar panel depends on its age, model, condition, and testing results. Well-maintained used panels that are only a few years old often retain 80-90% of their rated wattage. Older panels may retain 60-80% of rated output. Performance testing is key to determining actual power output.

Second-hand modules are sold according to cost per watt as this is the most standardized way of pricing them, similar to how the prices of new solar panels are compared.

As of 2023, the price of a used solar panel can be as low as $0.10 per watt. Even at $0.60 per watt, used solar panels are easily snapped up.

The price of used solar panels has continued to decline in recent years, as the technology has become more efficient and affordable. This has made used solar panels an increasingly attractive option for homeowners and businesses looking to save money on their energy bills.

The low price does not mean that the photovoltaic (PV) panel is at the end of its lifespan. No doubt, the older the panel is, the lower its efficiency level will be and, thus its cost. Most used solar panels for sale are aged between 1 and 9 years. These still operate at a high-efficiency rate.

The value of used solar panels also lies in the materials used to make the solar cells. Photovoltaic cells contain elements such as silver and tellurium. These are rare and non-renewable resources that can be extracted from the used solar panels.

solar cells
Photo by Science in HD on Unsplash

A strong market exists on where to buy used solar panels outside of America. The demand goes as far as Africa, Asia and Europe. According to the International Renewable Energy Agency, there are already thriving online platforms in Europe for the resale of used panels. For example, www.secondsol.de and www.pvXchange.com.

Is Buying Used Solar Panels Worth It?

Let’s face it. A brand new solar power system is expensive. No doubt, the latest photovoltaic technology can generate twice the power of used ones.

Buying used solar panels can be worth it for DIY home solar projects or adding capacity to existing arrays. The key benefits are lower costs compared to new panels, often 50% less.

New models naturally come with a price tag at least double the cost of used ones. Even with the reducing cost of new solar panels each year, it still can’t beat that of used panels.

However, used panels come with more uncertainties about longevity and performance. Careful inspection and testing is essential.

A Buyer’s Guide For Used Solar Panels 1

The efficiency rate of a used solar panel is definitely lower than a new one. The reduced efficiency is caused by impurities creeping into the crystals of the photovoltaic material. Some of the electrons generated are attracted to these impurities instead of flowing into the electrical circuit.

A solar panel loses between 0.5 and 0.8 percent efficiency per year. Sooner or later, the panel will become completely dysfunctional. However, even with a 0.5 percent efficiency loss per year, a solar panel is still operating at 86 percent after 30 years.

For the thrift-seeker, used solar panels are a lifesaver. Some people even buy enough used panels to cover their roofs. This makes sense when there is an existing solar system and you’re just switching out the panels on your own.

The cost of the panels constitutes a relatively small part of the entire solar system installation. According to NREL, solar companies are charging around $2.60 per watt to install rooftop solar systems. About 63 to 91 cents of that go to making and delivering the panels.

Some buyers get only one or two used solar panels to charge a battery for their RV, or to power the lights of a shed. Used solar panels are ideal for small projects where you might want to keep costs low. A large number of off-gridders also favour used solar panels because of the cost and because they want to reduce the environmental impact of discarded solar panels.

used so lar panel 2
Photo by Vivint Solar on Unsplash

Considerations When Buying Used Solar Panels

Following are the key factors to consider when planning to invest in a used solar panel:

  • Age – Performance declines over time. Older than 10 years may not be cost-effective.
  • Model – Research panel specs and reviews when possible.
  • Condition – Inspect for cracks, moisture damage, discoloration.
  • Testing – Test open circuit voltage and short circuit current with a multimeter.
  • Warranty – Used panels won’t have original warranty. Source may offer short warranty.

1. Does The Used Solar Panel Work?

Whenever possible, test it before buying. To do so, you will need good, clear skies and a volt/amp metre. If it passes the two tests below, it should work.

First, do a simple voltage test to see whether the panel produces the voltage listed on the original sticker of the product. If the sticker is gone, try to look up the information online. From there, you can compare its current efficiency rate against its new-state rate and decide whether you’re being offered a fair price.

The second test you can do is to gauge the panel performance in terms of DC amps. Configure your meter for DC then expose the panel to the sun for at least 5 minutes. You should get at least 80% of the LSC rating on the sticker.

2. Look For Damages Or Imperfections On The Used Solar Panel

A solar array exposed to all sorts of weather conditions might be damaged by rain, dust, small rocks and all sorts of debris. Check for cracks in the panel, signs of moisture underneath the cover and PV cell connections that are broken.

Even if the solar panel gives you a good reading, any visible damages will likely affect its longevity. Bear in mind that buying cheap used solar panels don’t come with warranties.

Some damages are not visible, such as moisture build-up in the internal circuitry. This type of damage is more common with amorphous silicon panels.

If this problem exists, you will see fluctuations in the voltage output when you test the solar panel in the sun. These fluctuations may mean that the solar panel doesn’t work properly.

Sometimes the used solar panel may not have any imperfections except looking brown. This often occurs with older solar panels that are made from plastic substrate. A brown panel can still be efficient.

Another common issue with used solar panels is burned-out bypass diodes. However, this problem can be easily fixed, and you can get a really good bargain for this type of ‘damaged’ goods.

Lastly, there is the problem of a loose connection between PV cells in the panel. The connections can be fixed by soldering them.

3. Can You Do The Installation Yourself?

This is important because it can be hard to find a solar installer for second-hand solar panels. Some solar installers are reluctant to do the job when they don’t know the source and efficiency of the equipment. If you don’t know how to DIY and you can’t find someone to help, you might be better off getting a new solar installation.

4. Check The Seller’s Credibility

To reduce the risk of a bad purchase, you should only buy from a seller with an established credibility as a repairer. Alternatively, the seller should be able to guarantee the product is on par with generally accepted safety parameters, such as the IEC 61730 international standard. The standard indicates that the product has been tested for general inspection, electrical shock hazard, fire hazard, mechanical stress and environmental stress.

The seller would have already carried out quality control tests, measure amp, and voltage performance. The results would be documented in writing.

Some sellers can also verify whether the manufacturer’s warranty will transfer with the purchase.  If the manufacturer’s warranty no longer applies, some sellers can offer a third-party warranty.

5. Is The Seller Reputable?

Reputable resellers often come with success records and recommendations that can be easily found online. They would have professional websites, Google business listings, and social media profiles.

Some have positive reviews from customers and tend to be members of trade associations and/or chambers of commerce. In America, they may also be rated by the Better Business Bureau.

Many resellers list products for sale on third party online marketplaces (such as eBay and Amazon), clearing houses or exchanges. You can further reduce risk by reviewing the screening parameters of these marketplaces.

There are marketplaces and exchanges which are open to anyone, and do not offer any liability. There are also those that are exclusive to registered solar companies which meet member qualifications and come with business references.

To protect yourself, you should read all the Terms & Conditions before buying on an online marketplace. Look out for hidden transaction fees, which should be stated in the Terms & Conditions.

Lastly, if you are looking for a used solar panel as a replacement part, check with your insurance agent first. Some insurance companies may have connections to reputable repairers so that you can install the used solar panel safely and with the least financial consequence to you.

How much should you pay for a used solar panel?

Pricing depends on age, model, condition, and your testing results.

As a general guide:

  • Under 5 years old: $0.20-0.35/watt
  • 5-10 years old: $0.15-0.25/watt
  • Over 10 years old: $0.10-0.20/watt
  • Further negotiate price based on condition and performance

Customers opt to buy used solar panels as it saves them a considerable amount of money.  A 2023 article in Forbes magazine stated that the cost of new solar panels has fallen to around USD 3 to USD 4 per watt. But if you are lucky you can find used ones in good condition selling for around USD 0.20 to USD 0.60 per watt in most parts of the world.

How to test a used solar panel before buying?

Testing will help determine actual performance and condition, and you would need a multimeter and a few minutes to test the efficiency. Look for the following parameters:

  • Visual inspection – Check for any cracks, corrosion, moisture damage.
  • Open circuit voltage test – Test voltage output with a multimeter on a sunny day. Compare to expected Voc.
  • Short circuit current test – Test current output with a multimeter on a sunny day. Compare to expected Isc.
  • Check efficiency rating – Divide measured power output by the panel wattage to determine real-world efficiency.

Additionally, you may want to consider:

Voltage testing

Take the solar panel to direct sunlight and set the multimeter to the volts setting for testing the wattage. For this, touch the device’s positive lead to the panel’s positive terminal and then connect the negative leads to the negative wires.

In standard cases, the multimeter reading should be around 60 volts. If the results are too far away, consider skipping the panel or bringing in a professional to perform further checks.

Ampere testing

You repeat the same process as you did for volts testing, the only difference being you set the multimeter to the amps setting this time. Connect the negative and positive wires the same way you did in the last step and look at the reading.

The panel is in good condition if the screen shows around 3 amps to 3.5 amps. If the results are lower than 3, it indicates a possible fault with the device. In such cases, you can skip the purchase or consult a professional for further help.


Buying used solar panels can be a great way to save money and reduce negative environmental impact. However, it is important to do your research and inspect the panels carefully before you buy them.

Focus on panels 5-10 years old in good condition, and be prepared to negotiate the price lower based on testing results and aesthetics.

Used solar panels can be found in the secondary solar market and in online marketplaces.

Resources on solar panels

Here are a few resources that can help you learn more about buying used solar panels:

As photovoltaic technology improves, so will the demand for used solar panels. You just need to do the relevant homework before buying them. The tests and checklist in this article are relevant to individuals considering used solar panels for their home and resellers looking for a used solar panel stock.

If you are purchasing for personal use, you should keep in mind that renewable energy tax credits are not extended to used solar panels.

Searching for the best deal when buying used solar panels requires diligence. However, it is worth it as used panels can deliver significant savings over new.

Renogy 2PCS 100 Watt Solar Panels

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