Solar Panels are like the Energizer Bunny, They Keep Going and Going

solar panels like the energizer bunnyOne of the sites I enjoy reading is greenbuildingadvisor.com. They have articles that are centered around green building. One article I read in particular that I would like to comment on is “Testing a Thirty-Year-Old Photovoltaic Module“. In this article they discuss taking a solar panel that is 30 years old off a roof and testing it compared to the factory specs it was made with.

The solar panel is owned by Martin Holiday. To keep things in perspective, this was not a homemade solar panel. It was a factory produced retail solar panel, an “Arco Solar Panel”. This solar panel was installed in 1980. It is a 33 watt panel that (at the time as part of a bulk purchase) wound up costing $275. Incidentally, that meant a good bulk-price on a solar panel back in 1980 was $8.33 per watt.

But the main gist of the article and the point I would like to make in this one is regarding the longevity of solar panels. How does a 30 year old solar panel module perform? This one — with flying colors. It exceeded all factory standards for output and is still going strong.
solar panels maybe should have a 50 year warranty
Most solar panel manufacturers warranty their solar panels for 25 years. Many people are in the mindset that that is how long they last. The common notion is that even after 20 years, they are already showing noticeable signs of power loss — and by the time the solar panel is 25 years old it may be producing only 80% of its old volume of electricity. However, here we have a solar panel that is producing at 100% after 30 years.

How was the 25 year figure arrived at to assume the longevity of solar panels? There were not that many in use pre-1980. How many people have decided after 30 years to actually test them and post results about them? It appears the 25 year mark is highly speculative, and in fact they could indeed last much longer. Will this particular solar panel still be producing at full value after 35 years of use? 40 years? Even if it dropped 10% after 40 years — if you can still claim it is producing at 80% or 90% of its original specs after a half century of use — I would venture to say that solar panels are an excellent investment.

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