Used Solar Panel Deep Dive

Used Panels and Their Benefits:

If you know what to expect and know your way around used products, then used solar panels are a great, cost-effective way to go. Keep in mind that these panels will never be as good as brand-new ones, however, that shouldn’t deter you from considering used solar panels that can be more suitable for your budget.

Check out our selection of Used Solar Panels! 

Used panels can be considered any panels that were previously used by someone else or by a business. Open box, refurbished or remanufactured, returns that are still “new-in-box” and were not used by the purchaser are also considered “used” products. SanTan Solar acquires panels from other sources as well such as decommissioned solar farms, end-of-lease contracts, and inventories from other businesses.

Refurbished panels may have had some components of the panels replaced or repaired but would fall under the used market. Components like connectors, cables, junction boxes, or diodes are the likely parts that would be repaired or replaced.

Different Kinds of Panel Blemishes:

Used panels will be found in a variety of conditions and performances. Here at SanTan Solar, we are very transparent about the conditions and flaws affecting our used panels. Let's break down some of those flaws and what it means for the performance of our used panels. 

• Snail Trail - Snail trails are a common solar panel defect. Snail trails typically appear after only a few years of use and can be caused by a number of different factors. Minor defects in these panels can allow moisture to enter through the back sheet, causing oxidation between the silver paste and the encapsulation material. Usually, these lines appear dark or brown and occur near bus bars, on solar edges, or close to microcracks. Snail trails don't discolor the solar cell surface itself, but rather discolor the grid fingers of the same cell at the same position, causing it to look like a continuous brownish line. Several solar companies have been studying patterns of snail trails and it was broadly concluded that the mere existence of snail trails by itself does not affect power generation. While generally snail trails are no cause for alarm, they can indicate other defects such as microcracks, so they should not be ignored.

• Green Bus Bars - Green bus bars are caused when moisture gets under the water barrier and reacts to the metal bus bars, tarnishing the metal with a green coating. Because of this tarnishing, the bus bar does not work as efficiently conducting energy.

• Cracked Vinyl - Cracked vinyl is one of the few blemishes that you can easily fix at home! These cracks are not a huge problem in themselves, but they should be addressed and repaired promptly to avoid any water intrusion. Once any moisture has penetrated this barrier, you will start to see snail trails form and green bus bars, lowering the panel efficiency. To fix the cracked vinyl backing, we recommend using any silicon-based sealant (ie. - Flex Seal, GE All Purpose Silicone). It is always a good idea to test a small amount of your sealant to make sure it will not harm the remaining vinyl backing. Coating the cracked vinyl will help prevent water from seeping past the backing and frame seals. 

Why Buy Used Panels?

The best motivator for getting used panels is cost. Panels that are 50-70% less than new panels are what you can find in today’s market. Realistic expectations of performance are that used panels will not be at peak performance, but will be at good usable levels with plenty of usable life still to go. To take advantage of the used solar panel market consider the usage time of the panel. This will help determine the wear and tear on the panel and the likely performance. 

Check the extent of blemishes on solar panels. Some blemishes can impact performance and should be reflected in their cost. Check for warranty offered for the used panels. At SanTan Solar we put a one-year warranty on all our used panels. Determining what your solar power needs are can help you decide whether you want to use older used panels. Most new panels have an average lifespan of 25 years. Used panels for sale can still have 10 to 15+ years left. This makes used panels ideal for off-grid DIY projects where cost can be a factor.

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