Solar modules deployed in France in 1992 still provide 75.9% of original output power
New testing conducted at France's oldest PV system have shown that its solar modules can still provide performance values in line with what the manufacturers promised.
There's a typo in the title. If you go back to the original source (in french), they actually retain 79,5 % of their original efficiency, so even better than the article's title would have you believe.
I guess we can blame the French's confusing number system for that.
It supposedly comes from originaly counting in base 20 ( a.k.a : vigesimal system) in some proto-european language. There are traces of it in breton, albanese, basque and danish for example. Even in english, there is a reminiscence of vigesimal, in the "score", see for example Lincoln's Gettysburg Address which famously starts with : "Fourscore and seven years ago...", meaning 87 years ago.
I'm four-twenties-ten-nine percent sure that French counting is not confusing
Yes but is that the average panel, oraverage of still a working panels?
Careful using the word efficiency there, as it has a different meaning when talking about solar panels - it indicates how much energy the panel can extract from the light hitting it. The best modern panels you can buy are below 25% efficient, and since these are from the 90s they were probably about half that when new.
Wow, imagine where we'd be if Oil and Gas hadn't convinced almost everyone that solar was never going to work well.
Imagine where we’d be if people didn’t automatically think nuclear power=Homer Simpson
The great thing about nuclear power is that the real cost only comes after the power has been generated. How do you store the spent fuel cells and what do you do with the reactor when it can't be used anymore. Just before that happens you spin the plant into its own company. When that company goes bankrupt the state needs to cover the cost, as it isn't an option to just leave it out in the open.
Privatise profit communalism cost.
Imagine where we'd be if leftists embraced nuclear power instead of killing it off everywhere they could.
I thought that solar panels that old performed much worse or stopped working. Especially considering where the tech was in the 1990s.
I thought that solar panels that old performed much worse or stopped working. Especially considering where the tech was in the 1990s.
"performed much worse" is compared to today's manufactured panels. As an example, a 100w panel in 1992 was likely around 12% efficient. This means "of all the light energy hitting the full panel under perfect light and temperature conditions", 12% of that energy is converted to electricity and would produce 100w. Compare this to a middle-of-the-road panel you'd buy for your house today the efficiency is 21%. Both the old and the new panel's efficiency will go down over the years.
What the article is talking about is how much of the original efficiency is retained over the years in real world tests. Lets say we have a 1992 100w panel from my example above at 12% efficiency. That means under the best possible conditions it would generate 100w. Because of age, the article notes that efficiency has degrade to produce 79.5% of its original rating. Meaning this 1992 100w panel today would generate 79.5w. That's still pretty darn good and useful!
There is a solar plant in switzerland that still has functioning panels from the early 80s.
E: Oh, the one I thought of was mentioned in the article already.
They work fine, just not at full capacity. Financing and payback calculations tend to assume they'll be replaced after 30 years, but that's just guesses made by accountants, not reality.
Similar holds for EV or phone batteries. They usually don’t suddenly die, but lose more and more health over time. Realistically, you have to set a threshold, where you call it no longer useful.
If the life expectancy was 80%, then we’ve passed it and they are due for replacement. If it was 70% the they still have years of useful life.
It’s probably one of those two. For phones, I replace batteries when health drops to 80%, because I spend too much of my life online. Also, I’m probably giving my phone to my kid about then, so they deserve a fresh battery. I have kept phone batteries down to about 70% life, but then it usually doesn’t last the day and I’m carrying portable chargers everywhere
I haven’t had an EV long enough but I believe the typical battery warranty is defined like that: not just that it’ll work for 10 years, but that it will still be at least 70% health after ten years
As far as I know that's nothing to write home about, monocrystaline solar panels get like ~30 years dropping down to 80% and then slowly begin to fail from there. I'm far from an expert, but my understanding is this is the norm and that if we found out they weren't lasting this long then people would be getting worried about a messed up cost calculous.
That's correct, but most of those calculations were based on theoretical figures used by artificial aging methods and computed failure rates. Now we have real world data from panels that actually aged that long.
It's funny how all the FUD idiots say that solar panels will wind up in the landfill and shit like that
It's a stupid argument against solar power, but it is a legitimate argument against cheap and poorly-constructed solar panels that do not have the same longevity as the ones built in the 90s.
The one's made now have plenty of longevity. They don't base the replacement time on when they actually go bad, and as long as they're not abused or get hit by bowling ball-sized hail or something, they'll keep producing some kind of power for a long time. It's just that for the space they take up, it may be worthwhile to replace them.
Same with EV batteries. They might have limited range after 10 years, but they could still be useful for things like home backup power without having to do a whole recycling job.
Is there a problem with the market being flooded with cheap not very good solar panels? Every single panel I looked at to put on my roof have all been of the highest quality I've not seen anyone try and hawk anything substandard.
Unless of course they're lying about what panels they're using but realistically I can't see that lasting for very long.
I still plan on retiring my solar panels once I retire, or later
The weird thing is that in this scenario these panels are still applicable for replacement probably because the the solar panels of today compared to then are about ~40% more efficient. So compared to a new replacement it's at around 60% efficiency. A major site plans profit off of 30 years and plans to replace glass at that time, so while it may still be somewhat useful long term it's probably more profitable to replace them.
I wonder if this type of economic calculus would mean a supply of inexpensive, second-hand panels might be available in the next few years.
They already are, at least for the smaller ones. You can go to your citie's parks and recreation department to get some. All those solar panels that power various signs and lights have been collected and replaced for years. I picked up a few years ago in Lexington, KY, for next to nothing, and they worked just fine for the lights that I wanted to power, despite only outputting less than 50% of their original power.
Not sure where you would find the full size ones like these pictured.
I doubt they put out much power at all compared to modern panels. Solar back then was a pipe dream, we didn't have the battery technology to store the energy and the panels had a lower voltage and could supply less current.
I have a 100w foldable panel for camping that at >= 20% efficiency is probably double what the 90s panels could do.
In the 90s, rooftop solar was around 10-15% efficient. Now rooftop panels are closer to 20%.
Some are 25% now, and don't even break the bank. You can get modules that store the power and feed it back into your house for use later. I kinda want to get some to offset heating and cooling costs.
https://us.ecoflow.com/products/175w-rigid-solar-panel?variant=41362064179273
A major source of calculator power!
Oh yeah, how about coal? Does that get any less efficient over time? Exactly. I've been burning the same lump of coal for easily the same amount of time and it remains 100% efficient, that's the beauty of combustible fuel.
It’s good to know that they have pretty good longevity. One thing complicating this is that panel technology has gotten better and better during that time. There’s a graph on Wikipedia plotting how much better the various types of panel have gotten since the 70s. A lot of them have doubled in output since the early 90s.
So on the one hand, these old panels are outputting 75% of what they started with, which is good. But on then other hand they are only outputting about 37% of what new panels could.
Not that we should throw old panels away. There’s plenty of sun to go around (though I guess the average homeowner only has one roof to use). It’s just interesting how fast the tech has improved and how that might factor in to some longevity calculations.
If that became a problem, every old panel could be changed by newer ones and the old ones could be installed in a desert until their EOL.
Right, they could be installed in the middle of nowhere as free phone chargers and stuff even if there was no other use for them. Just set them up with a used inverter and some used chargers, whatever etc.
Or maybe a whole lot of them could be put together in the middle of nowhere to make an EV charging station
I'm getting some new panels installed this year, and I think they're suggesting they'll be at 80% after 25 years.
It looks like there is disagreement between the title and content of the article. Title says 75.9, content says 79.5
Either way, does this suggest that new panels might do better than expected over a 30 year timespan?
Title says 75.9, content says 79.5
Looks like there's a typo in the English title. The French one has 79.5%.
To give you an idea, my 12-panel PV system installed in 2011 has put out 3.5 MWh per year at its peak and now produces between 3.1 and 3.3 MWh yearly, depending on the weather.
It's hard to attribute that just to panel degradation, though. It could be differences in weather (cloudier or snowier this year) for example.
To measure degradation, you'd need to track the peak output of each panel. Enphase microinverters let you get per-panel metrics but I'm not sure which other brands do.
I'm pulling data from my panels into Home Assistant via Enphase's local API (directly from the device), then into VictoriaMetrics (which is similar to Prometheus but with a more efficient file format). I've got per-panel production data at 5 minute granularity from when I installed them until now.
Newer panels are generally much more efficient and produce more electricity compared to old panels.
The 80% after 25 years might be their warranty, my panels have a similar warranty on them. If they start producing less than 80% of their original output before 25 years, the manufacturer will replace them (or something like that).
Fortunately and unfortunately, there have been so many changes and breakthroughs on solar power over the last 50 years that this doesn't really tell us much about current technology.
What's not included in the article is how much additional power might be produced by replacing them with newer systems.
Sure but you also haven’t lost any of the power that wasn’t generated by them being dead/broken
What you are not considering is that silicon crystallisation and the PV panel manufacturing process in its entirety are very resource-intensive and energy-intensive. The longevity of solar panels is one of their core properties that contribute to their high degree of sustainability.
This is gonna sound so dumb... But they had solar panels back then?!
Carter called for solar panels to be installed on the White House in 1979. Modern ones are probably way more efficient but they were definitely a thing.
Solar panels have also been used in space mission for a very long time. The first solar powered probe was Vanguard 1 in 1958
Jesus Christ. Look, back in the Stone Age when I went to school the coolest calculator was the TI-36 Solar. It was already that mundane.
Naturally, I used a non-solar Casio, because I wasn't one of the cool nerds.
damn you just reminded me my mom bought a basic calculator with tiny solar panel 25 years ago : it is still working !
And then there are the calculators with fake solar cell windows
Sounds like you should install double what you think you need. Reason? The panels will start losing efficiency over time and your electricity usage over time will do nothing but grow. That's very common.
Dude.
Those panels lost only 20%, so far from half, in 32 years.
That's impressive.
I didn't say they lost half but they lost 20% so you need to have at least 120% today and then you need to account for the fact that you will get more electric devices in the future. How are you going to charge your electric car if you don't have the electric to do it? So therefore you should probably double it.
