Anyone know what the state of the art is/will be for panel lifetimes? Efficiency is great, but I’d sacrifice some if it meant 50+ year lifetimes of 85%+ peak output.
Long story short: scientific researchers, especially those in well funded laboratories are incentivized by the wrong metrics (in all fields, not unique to solar) and in this field the only metric that matters is efficiency. It doesn't matter if your cell decays by 50% in a day, it reached some great potential in a new way, here's the way for a high impact publication.
Want to work on the other problem though? Lifetime, resiliency? Cheap and affordable and non-toxic materials?
Good luck getting proper funding and exposure. Why? Because scientific papers are a closed mafia, where a set of the most influential scientists (doesn't matter how many scientists the planet has, the moment you start entering a niche the number of people is very low) in their field review the submitted papers. Don't have high efficiency or you're not breaking science? Forget a high-impact journal. You're back at B-tier, C-tier papers, but those won't get you funding and status. Not great for your career.
So what do you do? You play fool and focus your efforts and many many millions of euros to get the next perovskite cell that can reach high 20%s with some twist at least or go for the 30%+ ones.
Just to express how sad and toxic the world of scientific research is (not even mentioning the insane amount of fake data that gets published every day, the politics, etc): instead of being a researcher I now prefer being a web developer writing forms list and tables.
As a society we have decided that (e.g.) physics should/shall solve our problems with better technology. But that is not what pure academic science is about, or what pure academic scientists care about.
You want to iteratively improve technologies? Give more funding to proper engineers, not physicists/chemists, even if they're sometimes in the 'school of electrical engineering'.
If you've been in this field, I'll gladly listen to your experience.
FWIW you've helped me understand some of why we keep seeing these efficiency publications that never make it to production. What is impressive is the degree to which cost has reduced as a result of economies of scale and I wonder what the bottom is there. Compared to the price of solar panels even 16 years ago (when I did my previous large installation) it is amazing to be able to get panels at todays' prices for what I perceive to be much better quality panels.
But inverter quality seems to have gone down compared to what I was buying back then, though they too are cheaper.
Scientists tend to be interested in 'neat cool solutions' or 'neat cool problems' and there should be separate funding for 'important problems with boring solutions' that sits separately to current science funding. I agree leave the small-scale iteration to industry.
Materials science departments are often called "Materials Science and Engineering". How do they fall in your categorization?
Without disrespect intended, your words sound like those of someone who has never spent any time in graduate school in a engineering program in physical disciplines. The lines can be blurry.
My comment was worded strongly, I meant more that funding could come from different streams fo4 different purposes.
Since there's also a much bigger solar industry today than in 2007, you also see more practically-minded research coming out of corporate centers (Longi, Oxford PV, GCL System Integration, and others working on perovskite cells and perovskite-silicon tandems). Since they care about shipping real products, they are focused on solving lifetime and durability issues. Of course since this research can give a big commercial edge as single junction silicon reaches its efficiency limits, you'll also only see the really promising work published after it is patented.
It makes sense that researchers should be considering metrics other than efficiency as well for new materials or architectures, and there's no reason why this is a uniquely industrial pursuit.
Grandparent's comment resonates - efficiency claims seem to be the only ones generating press releases.
One thing I've found frustrating is that solar installers don't seem to understand, or want to share, the fundamentals. They do it one way, the cookie cutter way.
For example, most sites are space-constrained and that leads to concern about efficiency. I'm less space constrained, but that doesn't seem to change their ideas.
Most people have fixed-pitch roofs, so angles are what they are. Being flat, I choose the angle, and direction. There's very little data though on the best angles or the best direction. Are adjustable angles useful? Should I bias the direction to the west to compensate for morning/afternoon consumption patterns? All i get are blank stares.
On the up side, being forced to figure it out is interesting. And over the next few years I can generate actual data, testing various approaches, to see what actually is the most useful approach.
Sure, panel efficiency gets all the glory, but there's a lot more involved once you start building a system, and I think more practical research could be done there.
[1] one interesting point is the cost of the frame versus the cost of the panel. If I just "lie the panels flat" the frame price is negligible. Sure the panels are less productive, but Does spending the frame money on more panels offset that? Is overall production (not effeciency) better or worse? Factoring in summer as well as winter production.
[2] my city allows me to feed power into the grid, giving me about 40% credit. They are effectively a very large, 40% efficient battery, with no capital cost or maintainence cost. Plus they are long term, I can "charge" the battery in summer, use it in winter. I've yet to find an installer though that understands why this is good - they all balk when I say 40%.
When you look at it from a financial perspective in a net metering setup it is a bit less efficient, but when you look at it as if netmetering no longer exists (which I expect will happen here soon) then it suddenly comes out way ahead. It also has the added advantage that it avoids generating a lot of power when the power price is potentially negative.
My daily surplus in summer months is 80 KWh give or take, but during the winter, even with all this generating capacity I'm still running short. But proper insulation helped to cut down the gas consumption considerably and now energy costs for the whole house (about 2000 sq ft, freestanding) is < 300 euros / month including last winter's gas prices. Next winter should be better still (because I now have 18 more panels).
Total installed capacity is 16 x 265 (older panels) and 34 x 370 (newer, glass-glass panels). Inverter capacity is 4 KW on the high roof and 17 KW on the low one, with about 12 KW of output during the peaks in the summer.
Best day of the year so far made 99.8 KWh, worst days can be a few KWh so then you really need the grid. Average power draw of this house when we're careful is ~300 Watt, but cooking is a pretty big (and usually short) exception to that as is running the water cooker (but that's only a minute or two and during the day doesn't begin to approach the amount of power generated).
One downside of having panels flatter is that they foul up, some 3d printed clips helped with that but it isn't perfect.
I've heard of the flat-flat problem of pooling water, so I'd likely be at least 10 degress of angle.
20x480 is a pretty good system to start with! And yes, insight comes with time, I'm lucky in that I already did a ton of this stuff while in Canada 20 years ago so now I can re-use that knowledge. One of the better things I did here is to create a covered space next to my garage that uses the panels as roofing. Two birds with one stone: very nice covered space and glass-glass panels allow some light to shine through and it helps keep the panels cool because there is plenty of airflow underneath them. Mounting them flush with some polymax in between to make it all watertight was a bit of a job though.
https://www.nrel.gov/docs/fy22osti/81172.pdf#page=5
Some types of panels have increased capacity after being in the field for years. Degradation is not a significant economic concern at this stage of the process.
This translates to about
* 0.999^25 = 97.5% to 0.989^25 = 75.8% output after 25 years.
* 0.999^50 = 95% to 0.989^50 = 57.5% output after 50 years.
Many regions of the world are getting dryer. You might just be seeing a global warming side effect as there is less cloud cover.
* The actual silicon is degrading
* The cover glass is getting dirty/frosted/delaminating/optical adhesive is no longer clear
* Electrical failure of a whole cell - for example it is cracked, yet the panel still appears to work due to the bypass diodes removing a whole cell from the circuit.
Sure - from the users point of view it doesn't matter, but from an engineering point of view, the cause of failure gives some clues how to prevent it.
> For normal incidence, approximately 4 % of the light is reflected; this value is determined by the refractive index of the glass. For most glasses with a refractive index of 1.5, reflection losses at the surface result in an approximate 4% decrease in light intensity.
But I would bet it is cheaper to buy insurance for such infrequent events.
Some research suggests you should replace all solar panels every 17 years because the tech will have advanced enough to make it worthwile.