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Estimating the Lifespan of Your Solar Panels

Hello again! So you're back for more thoughts from the guy who thinks he's heard it all? Turns out, I haven't - at least not yet. But one thing I do hear about regularly is a question about how long will my solar panels last.

Turns out, this is a question I've been trying to answer since we started 15 years ago. And even better, the answer gets better nearly every year. How's that you say? Well... read more!

I usually start this answer by referencing the fact that commercially available solar panels were first made available by Bell Laboratories in the late 1950s. That's right - solar tech has been around longer than most folks who are reading this blog.

Way back when (then) - solar panels were used for things like charging a battery on a channel marker in the ocean/river confluences. This in turn would turn on the "blinky" light and/or radio beacon so that ships could navigate these waterways.

Of course, they were used for many other things, but as fate would have it, back in 1959 the Coast Guard installed one of these solar panels on "Buoy 10" in our own Columbia River/Pacific Ocean right here off the Oregon coast. That solar panel was left in operation until 1999 - 40 years of experiencing the worst things you could throw at a solar panel: salt water, seagulls resting on it, waves rocking the buoy (and by proxy, flexing the solar panel) and...and...and. Let's just say that the solar panel on that buoy is a far cry from the safety and stability you have when mounting new panels on your property.

Well...when the time came to upgrade the buoy with better things like GPS, the Coast Guard pulled this solar panel off the buoy and donated it to a local university where it sat as an example for about 4 years. Again - fate stepped in and low-and-behold, SolarWorld decided to build a solar panel manufacturing plant in Hillsboro Oregon. When word spread that this new company was opening up, the university asked them to test the 1959 solar panel to see how it had fared during its working life. So one day, the students brought the old panel into the fab in Hillsboro where the SolarWorld techs calibrated their testing equipment to reflect the output of a 40+ year old panel. What they found was pretty impressive:

After 40 years in a horrible environment, the solar panel had seen only a 19% drop off in its production (as estimated on day one after rolling off the assembly line). That's right: 40+ years after being assembled, the solar panel was still making over 80% of its rated power - and all this using 1950's tech, 1950's manufacturing methods, and 1950's materials.

What we have available today (for modern solar panels) absolutely eclipses the tech seen all the way back in the 1950's. We have better manufacturing methods, better materials and processes to create the silicon that becomes solar panels, better, higher transparency glass that doesn't reflect the light it's trying to collect...and...and...and...

It's easy to see how and why reputable solar panel manufacturers have been offering their 25 and 30 year Production warranty: they know that stuff built over 60 years ago was and is testing better than their typical warranties they're offering today. So, should you just dismiss this warranty? Not at all - but keep in mind that it's very unlikely that you'll ever need to try to enforce it on your own behalf. Solar panels built in the early part of the 2000's are still testing out much better than 86% after 20 year on rooftops. And the tech just keeps improving.

So - what are the things to know before you start thinking about adding solar to your roof?

Well - first and foremost - if these are going to easily last 25 years, you should really think about how old your roof is and whether or not it makes sense to add them now or later (after a roof replacement).

Second - what about next year's solar panels? Will they be way better than this year's solar panels? In general - the answer here is: yes - they'll be better, but not 50% better - or even 10% better. Solar panels have done a few things every year that I've been around:

a) the tech keeps getting more efficient - this means that they're squeezing more power out of the same space (than they did a year ago)

b) in general - they look nicer than they did 20 years ago (when I touched my first solar panel).

So - another question is: should I consider REPLACING my solar panels?

For me, the answer I give goes back to an old bit of wisdom: if it ain't broke, don't fix it!

What I am suggesting here is this: We know that the production of the solar panels is very good for a very long time. Because of this, your needs from these solar panels will be met for years (and maybe decades) without needing to change them out. If you chose to replace the panels you put up 5 years ago with solar panels made just a few months ago, you'd gain about 15% more power output in the same area covered. But...if you don't need more power and your electric bill is still as low as it was in the first year of your ownership, then why mess with a good thing?

In my opinion, you won't need to replace your solar panels anytime soon - meaning for the next 20+ years if your needs don't change substantially. These babies are built to last!

Hope you find "Estimating the Lifespan of Your Solar Panels" helpful.

If you have more questions, feel free to reach out and make an appointment!

Until then - thank you for your time!


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