Things to Consider Before Purchasing Used Solar Panels

Although solar panel costs are reducing with the flow of time, some people can’t afford the expensive upfront system prices. If you are among these people, then you don’t need to destroy your desire to go solar. You too can reduce your electricity bills and contribute to a green and pollution-free environment by purchasing used solar panels.

Many online websites and suppliers in the marketplace are selling second-hand or used solar panels for homes and commercial buildings at the lowest prices. These systems can be enticing for you but don’t pick any solar panel randomly.  

In this post, you will find everything you must know before going solar in India with used solar panels. Look out for the following things when buying used solar panels.

Check their working condition

The very first thing you need to ensure is that solar panels must be in proper working condition. Check their functioning ability with clear sun and an amp or volt meter.

  • Voltage test – To do the voltage test, ensure the solar panels generate the same voltage as given on their sticker. If it is not producing the same voltage, then find the relevant information online for the pre-owned system you’re going to buy.

Bring the direct sunlight exposure and then set the multimeter to its volts setting. Connect the positive lead to the positive terminal and the negative lead to the negative wire. 60 volts is the standard multimeter reading. If the received reading is extremely far away from the standard value, don’t consider the panel.

  • Ampere test – The second test is to configure the meter for DC amps. It helps in ensuring solar panels perform well in the sun. Do the same procedure as you performed for voltage testing except for setting the multimeter to the ampere setting.

Connect the positive and negative leads. You must get at least 80 percent of the ISC rating on a sticker. Remember that you have to test it for 5 minutes while the system heats up. If your system passes both tests, they are still in effective working condition.

Check for any imperfections or damage

The used rooftop solar panels for home or ground-mounted solar panels were previously exposed to different types of environmental conditions. In addition, they have possibly been hit with small rocks, dust, rain, and other types of debris. So, look for any kind of damage like totally broken connections, cracks in the glass, or moisture below the cover.

If you don’t see any damage, the system is in proper physical condition. However, any sign of imperfection or damage can question their longevity. Sometimes there is no visible damage. For example, if a solar panel has moisture in the internal circuitry, you will not see any imperfection physically, however, you will notice fluctuations in the voltage output during the test. Your solar system will not operate effectively if there are any fluctuations.  

Duration of service

Duration or length of service is the duration in which modules were producing solar electricity on the roof before their removal for sale in the market. A solar panel with a short length of service has some worn-out components than systems under long-term service periods. If your seller is ready for negotiation, you can use extremely long service periods to bargain for reduced costs.

Consider the warranties

Most reliable solar manufacturers and suppliers offer product and performance warranties when you buy them to ensure optimum power production for the long term. For example, some solar companies offer a leading warranty for solar system for residential flats of 98% of the original output by the last of the first year and about 92% by the end of 25 years if you are purchasing a new system.

When you buy used solar panels, you might not get the same product or performance warranties. You may end yourself risking failure or less electricity production. So, before purchasing the system, look for the attached warranties.

Most panel warranties are transferrable from a real owner to another person. The warranty is transferred when a solar-equipped home is sold to a buyer who purchases the residential property with already installed solar panels. You will not get a warranty when purchasing solar systems throughout a marketplace or online.

Power production efficiency

Solar panels with outdated cell sealing, older technology, and heavy frames may not have more energy efficiency to produce a higher amount of electricity. They may not generate as much solar power as you require to meet the solar requirements of your home. This is because, with the flow of time, solar systems slowly lose their ability for great electricity generation. To produce the same amount of power that would otherwise be generated with new panels, you might need to install more solar panels. For this, you may have to arrange extra space on your rooftop.

Ask for the reason for selling

Every person sells solar power panels for some reason. To get an idea of the system condition, ask for the reason for selling systems. If another person is selling a system due to purchasing a highly power-efficient system or moving to a new home, then the system should be in proper operating condition. Prevent reasons that affect the solar system’s working condition like performance problems, storms, and damaged components.

There must be no loose connections

Solar panels are made using solar cells connected together in a series to create a circuit. The amount of electricity generated is dependent on how cells are interconnected in a series. Loose connections between the cells can negatively affect the solar cells’ performance. However, the loose connections can stay hidden. Loose connectivity can also obstruct the cells from collecting sunlight and converting it into power.

Cost and installation

The cost of used solar panels must be reasonable. Cheaper systems can be fishy and may not be of good quality. There might be some problems with the panels like reduced electricity output, damaged wiring, etc. When you are buying solar panels online, don’t rely completely on descriptions and pictures because they may not cover everything.

Searching for and hiring a solar installer for the used solar panels installation is challenging. The reason is that the long-term performance and quality of used solar modules are doubtful. Local installers may hesitate to provide installation services for those inefficient projects.  


So, this is all you must keep into consideration while buying second-hand solar panels. However, to get the best value for your money, ask reliable solar company to know if used solar panels would be the safe investment for you.

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