Do you look at your solar panels and wonder if it’s time for them to go? Here are three signs that you need to replace your solar panels — along with three common false alarms.
Solar panels are built to last. Most panels can handle winds of up to 140 mph speed. To pass manufacturing standards, PV modules must be able to withstand the direct impact of hailstones about 1 inch in diameter falling at 50 mph. Still, they aren’t immortal. Over the years, solar panels may crack or delaminate.
Any physical damage to your solar panels, such as cracks, scratches, broken glass, delamination, hot spots, snail trails will inevitably degrade your system’s performance. If you notice any sign of damage, contact a professional to decide whether to repair or replace the damaged panels.
Solar panels gradually lose their efficiency over time. This is a natural process and is called solar panel degradation.
A degradation rate is usually shown as a graph in the panel’s spec sheet. The first year is the toughest for your panels, as they can lose from 2 to 3% right away. Starting from year two, the degradation rate ranges from 1% to 0.2%, with an average of around 0.7%, according to the National Renewable Energy Laboratory (NREL).
Take an average 400W solar panel. During the first year, it will lose 2-3% of its output, starting with year two, another 0.8%. In 10 years it will run at 90%, being a 360-watt rather than a 400-watt solar panel.
Most solar panels come with a 25-year warranty for performance. If what you module provides is significantly lower than what the manufacturer had promised, you can contact them and ask for replacement.
If your entire system is fine, but you’ve started running out of power, perhaps your consumption patterns have changed. If you started working from home, bought an electric vehicle, or switched over from gas to electric heating, perhaps it’s time to expand your solar system and add more solar panels.
The problem is that adding solar panels to an existing system requires them to be the same in voltage and output. Finding panels that will match the ones you have on your roof can be tough. That’s why sometimes it makes sense to replace an old system with a brand new one. Read more on the subject in our article on how to add solar panels to your system.
People often come to me and ask for panels that are rated at 300-330 watts because they want to replace a broken solar panel in their old system. I can’t help — these panels don’t get produced anymore because manufacturing moves on to more powerful modules. If you’re looking for old panels for replacement, try eBay or Setpile.
Upgrading solar panels is expensive, and solar panels make up most of its cost. While a decrease in power generation is the clearest sign you can’t ignore, it may happen for a variety of reasons. So before blaming solar panels and sentencing them to replacement, make sure they are the problem. Apart from them, there are some other suspects to blame.
Dust, dirt, rain stains, dry leaves, bird droppings – there are so many things you can find on your solar panels. Over time, this turns into a layer of grime and slowly but surely brings your solar system’s performance down. Dirty and dusty solar panels, especially in desert and wildfire regions, can generate 17-25% less energy, according to the American Chemical Society. But all you need to do to restore their performance is to give them a good wash.
The inverter has more duties than any other part of the system. Yet it is also more likely to break down than any other part of the system, according to the PVEL report. Most inverters have an average lifespan of 10 to 15 years, compared to 25 to 30 years for solar panels. If you installed your solar system quite a while ago and it has started to fail, check the inverter. If you have just recently replaced it, there may be another problem – the inverter capacity does not match that of your solar panels, reducing their output. Read our article on solar inverter maintenance to learn how to make it last longer.
Wiring ties the entire solar system together. If squirrels have chewed up the wires or the storm has loosened the connections, the electricity flows from the solar panels to the inverter and from the inverter to your home will be disrupted.
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Years of experience in translation and a love of nature help Julia find the right words to encourage going solar. She joined the team in 2023 and is happy to make her contribution to a greener future.
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