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Aptera Solar panel/cell info (2)
_________________________ Older posts for this thread can be found at: https://aptera.us/community/discussion/hood-colors-without-solar/ ______________________________
If one of the solar cells is damaged (impact/malfunction) will it take out the whole sub array (hood/dash/roof/hatch)?
Now that DC fast charging has been confirmed, my only concern with the Launch Edition is the solar hood. I did not order it in my previous custom configuration, as I feel those cells will be very susceptible to impact damage (i.e. rocks). Does anyone know what happens if one cell of the hood array is taken out of commission by an impact? Do you lose only that cell’s output? Lose a full row? The whole hood sub-array? Hopefully the hood sub array would be the worst case, and one damage hood cell will not bring the entire solar package to 0 Watts… As I feel damage to those cells is basically guaranteed if you own the car long enough, and will likely be a pain to fix, I would like to know how Aptera has configured the cells (also useful to determine what happens with partial shading, such as a bird poop or a leaf on one cell).
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23 Replies
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Aptera Solar panel/cell info (2)
M T updated 3 months, 2 weeks ago 11 Members · 23 Replies
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First, realize that each panel (hood, roof, dash and hatch) will likely act independently of each other. This simply means that any damage to one will have no impact on any other.
“Specifically the question is if one of the solar cells is damaged (impact/malfunction) will it take out the whole sub array (hood/dash/roof/hatch)?”
For the most part the worst case scenario is a single cell becomes an “open circuit”. If that happens, the bypass diode, to the extent there are any, will shunt the current from the rest of the string around the opened portion. The problem is that it’s possible that the resultant voltage loss may reduce the string voltage to below the minimum needed for proper operation of the MPPT.
“As I feel damage to those cells is basically guaranteed if you own the car long enough, and will likely be a pain to fix,….”
Fixing would be difficult but not impossible. Replacement is likely the better option.
I, too, am interested how Aptera has configured the cells…..
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I seem to recall them saying that each solar panel would have a few (2 or 3?) independent zones (probably because of the curve?). Does anyone remember the details from that?
Fixing would be difficult but not impossible. Replacement is likely the better option.
Maybe drilling into the panel from the back and putting in a shunt over the bad cell? Encapsulation would be ruined though, so the panel would probably fail within a year or two.
10 years down the line it might be interesting to see if they have replacement panels available with upgraded (multijunction?) cells.
I wonder what failures they are expecting past the 10 year estimated life of the panel. Is that them just being cautious?
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This reply was modified 8 months, 1 week ago by Michael Marsden.
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This reply was modified 8 months, 1 week ago by Michael Marsden.
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This reply was modified 8 months ago by
Gabriel Kemeny.
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This reply was modified 8 months, 1 week ago by
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I seem to recall them saying that each solar panel would have a few (2 or 3?) independent zones (probably because of the curve?). Does anyone remember the details from that?
That is my recollection as well but I have no details.
Maybe drilling into the panel from the back and putting in a shunt over
the bad cell? Encapsulation would be ruined though, so the panel would
probably fail within a year or two.The drilling/bypass idea is how I would approach it. I’ve done, essentially, the very thing in the middle of the outback at night under a big tent on a 1/4 million dollar array on a solar race car! If done well, I see no reason to expect the encapsulation to be ruined.
10 years down the line it might be interesting to see if they have
replacement panels available with upgraded (multijunction?) cells.Agreed. I’m thrilled about the possibility of so-called “hybrid” cells. Essentially Perovskite on Silicon. https://www.oxfordpv.com/perovskite-silicon-tandem-cell
I wonder what failures they are expecting past the 10 year estimated life of the panel. Is that them just being cautious?
Based on the panels Aptera has made that I’ve seen/studied, I see interconnect failure as the “weakest link” and delamination as the second weakest. I’m not referring, by the way, to the same delamination as seen on the recent hood panel. Also, I feel Aptera’s current expectation of 10 to 15 year lifespan of the panels is a bit optimistic.
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How does damage to any of the solar cells affect the solar charging system?
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Normally there is a bypass diode, so that a shaded or faulty cell will not generate power, but it won’t block the rest of the panel. There are some specific scenarios where the bypass diode won’t help (partially shaded or partially faulty cells where they still generate a little power, for example). Note that the bypass diodes can also fail, although this is less common than shaded cells.
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This reply was modified 8 months ago by Michael Marsden.
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Normally there is a bypass diode, so that a shaded or faulty cell will
not generate power, but it won’t block the rest of the panel.Only true if there is a bypass diode on EVERY cell which is unlikely. It is more likely if a cell is “mismatched”(*) enough, some number of other cells will, indeed, be “blocked” and also not generate power.
There are
some specific scenarios where the bypass diode won’t help (partially
shaded or partially faulty cells where they still generate a little
power, for example).Strictly speaking, activation of bypass diodes doesn’t depend on the power generating capability of a cell or group of cells, it depends solely on the voltage of what it is connected across. If the voltage goes negative enough due to enough current mismatch, the diode activates. This can and does happen even with partially shaded or partially faulty cells.
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This reply was modified 8 months ago by
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Posted on the socials: Aptera solar is moving from Gamma to Delta…
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What does this even mean?
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Marketing seems to assume that their message makes sense to others……
We might learn something during the webinar tomorrow.
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While there’s some fluff in this long video, most of it deals with the solar panels starting around 8:05 – given the Accelerator figure Audra mentioned, this is about a month old.
APTERA factory tour 2023! INSIDER updates on solar, funding, and production timeline!! – YouTube
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I saw CA in the background probably giving an interview. I liked the “oops” moment when he (not CA) picked up a solar cell and a connection to the next cell broke.
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This reply was modified 3 months, 2 weeks ago by
Dennis Swaney. Reason: Clarified to whom I was referring
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This reply was modified 3 months, 2 weeks ago by Gabriel Kemeny.
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This reply was modified 3 months, 2 weeks ago by
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Found that a bit concerning, I’m curious as to how durable/rigid the solar arrays are after lamination.
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Certainly more than bare cells.
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Far more durable. The increased thickness of almost any laminate adds significant durability by almost any measure.
Depending on the layers of laminates…somewhat more rigid with simple backing sheets, can be much more if directly laminated to something structural like PCB, fiberglass or CF.
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I would hope the hail simulating cannon was aimed at various point and not just the center of each cell. They are good engineers so I doubt they would miss something so basic. While Aptera is pushing solar up to 11 they are not the first vehicle to put cells on a car; anyone heard of issues with the solar roof on the prius prime or others?
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If I’m not mistaken, there are prescribed “locations” on where to hit a solar panel with the ice ball testing.
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My concern is that they seem to have used “normal” hail impact, like a roof solar panel would suffer. A car going 70 mph could well be more a difficult case. Oblique impact, but higher speed. We will at least have the Accelerator Program cars to real-life beta test in storm season 2024.
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I imagine the windscreen would immediately shatter with that sort of impact. Hopefully people wouldn’t be driving too fast if there were golf-ball sized hailstones coming down.
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Based on the video in the post above, there are seven separate strings on a full solar setup. Worst and unfortunately typical case is the loss of the entire string’s output. ~100W would be lost if all the strings are roughly equal to make up the total of 700W. If the production hood has 26 cells, 93.6W charging capacity would be lost.
My experience with fixing a laminated solar panel is that it would be tough and impractical to do. Damage to other cells would be likely. My estimate for the replacement panel as a replacement part would be in the $250-$400 range…hopefully less once fully automated in production. Maybe $50 – $100 labor to have someone do the swap.
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I remember chris Anthony stating that a broken solar cell will still produce most of the rated power and with the proof provided in this video I believe even a shattered cell will still function just fine.
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I remember chris Anthony stating that a broken solar cell will still
produce most of the rated power and with the proof provided in this
video I believe even a shattered cell will still function just fine.A “simply” broken solar cell will still produce most, if not all, of the rated power for, at least, the short term. A “shattered cell” will not. Please watch the quick vid I made showing the difference between a non-broken and a broken Maxeon cell. The broken cell wasn’t “shattered” yet it still lost about 15% of it’s peak power current (Imp). That is enough of a bottleneck of current that it likely would limit the rest of the string it’s in or lead to the turn on (shorting) of bypass diodes.
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This reply was modified 3 months, 2 weeks ago by Alain Chuzel.
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This reply was modified 3 months, 2 weeks ago by
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