Author Topic: Home Rooftop Solar Power System Update - Shattered Panel!  (Read 41240 times)

0 Members and 1 Guest are viewing this topic.

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29650
  • Country: au
    • EEVblog
Home Rooftop Solar Power System Update - Shattered Panel!
« on: December 06, 2015, 03:57:06 am »
One of Dave's LG Mono-X solar panels has mysteriously shattered!
Daily solar output data: http://pvoutput.org/list.jsp?userid=22501
Sorry for the audio and video quality, this was shot on my phone.

 

Offline djQUAN

  • Frequent Contributor
  • **
  • Posts: 252
  • Country: ph
    • My DIY website
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #1 on: December 06, 2015, 04:16:12 am »
Stray bullet perhaps? or someone with a slingshot and BB/marble?

PV modules are made with tempered glass which are pretty strong against wind and hail but shatter into a million pieces when cracked. I think you could just get a spare and use the broken one until output drops significantly to maximize your investment then replace it immediately.
 

Offline Radio Tech

  • Frequent Contributor
  • **
  • Posts: 933
  • Country: us
  • KC4UMO Buddy
    • Hobby Forum
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #2 on: December 06, 2015, 04:16:59 am »
Solar roadway  :-DD

Almost looks like a baseball maybe? Interesting.

Offline DrGeoff

  • Frequent Contributor
  • **
  • Posts: 709
  • Country: au
    • AXT Systems
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #3 on: December 06, 2015, 04:22:02 am »
Looks like a misplaced cricket ball or golf ball landed on your roof.

Remember LG = Lucky if it Goes :)
Was it really supposed to do that?
 

Offline ornea

  • Supporter
  • ****
  • Posts: 107
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #4 on: December 06, 2015, 04:23:12 am »
Anything get caught in the gutter?
« Last Edit: December 06, 2015, 04:25:04 am by ornea »
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29650
  • Country: au
    • EEVblog
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #5 on: December 06, 2015, 04:23:16 am »
Stray bullet perhaps? or someone with a slingshot and BB/marble?

No way a marble had enough energy to shatter that.
We don't have a gun culture in Australia, and so hardly anyone has one. So the odds of that are borderline zero.
 

Offline chickenHeadKnob

  • Frequent Contributor
  • **
  • Posts: 801
  • Country: ca
  • doofus programus semi-retiredae
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #6 on: December 06, 2015, 04:24:55 am »
I live about 400 meters away from the ocean where mud flats get exposed at low tide. Gulls and ravens pick up mollusks and crabs and such during low tide. The gulls fly to about 20 or 30 meters altitude and drop their goodies on rocks right at the beach, to crack them open. The ravens on the other hand bring their stuff to my house and hammer away like a construction crew on my roof. They only do this during the months of late march through to about early july and only in the mornings. This might be because of the pacific ocean mixed tides are low in the mornings  at this time of year and they have young in the nests in nearby trees they need to feed. They only come to my roof!, its infuriating, and I don't know what's special about my house. My shingles are holding up, but I suspect solar panels wouldn't last. Those phu**kers like shiny things and would make use of hard edges as anvils for sure.
 

Offline djQUAN

  • Frequent Contributor
  • **
  • Posts: 252
  • Country: ph
    • My DIY website
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #7 on: December 06, 2015, 04:26:26 am »
I wouldn't think a baseball could break the glass since it is tempered and the ball is kind of soft. Although it could happen with sufficient force but from above? Not really sure.

What could do that kind of damage to a tempered glass panel is something hard like a BB, bullet, marble or rock. With a small, very hard pointed object, it doesn't really take a lot of force to break tempered glass.

A small bit of cracked ceramic from a spark plug thrown by hand could easily shatter car windows.
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4295
  • Country: ca
  • Canadian po
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #8 on: December 06, 2015, 04:27:20 am »
I think the answer came from the sound half way through the video. An airplane.... Perhaps something fell from an airplane, a bolt, nut, piece of ice....
 

Online Psi

  • Super Contributor
  • ***
  • Posts: 7279
  • Country: nz
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #9 on: December 06, 2015, 04:56:06 am »
If its still working maybe just add an extra panel instead of replacing it.
It's going to fail eventually as water gets down the cracks but might as well use the power while its working.
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline ornea

  • Supporter
  • ****
  • Posts: 107
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #10 on: December 06, 2015, 05:02:26 am »
As a string of panels are in series, the impedance of a single panel can drastically effect the overall performance of the string. If it fails sorted not so bad I think but if it fails with increasing resistance, not so good.
Therefore it is best to replace to maintain peak performance.   
 

Offline djQUAN

  • Frequent Contributor
  • **
  • Posts: 252
  • Country: ph
    • My DIY website
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #11 on: December 06, 2015, 05:06:27 am »
PV modules have bypass diodes so when it fails or output drops, the array still works but the total output drops by one module.
 

Offline Klomderper

  • Contributor
  • Posts: 5
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #12 on: December 06, 2015, 05:09:39 am »
I would add CCTV cameras to monitor the panels and surrounding areas.
 

Offline NoItAint

  • Contributor
  • Posts: 33
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #13 on: December 06, 2015, 05:23:24 am »
Maybe a Ninja rock from a stupid kid sling shot?
https://en.wikipedia.org/wiki/Ninja_rocks

 

Offline rs20

  • Super Contributor
  • ***
  • Posts: 2150
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #14 on: December 06, 2015, 05:42:10 am »
As a string of panels are in series, the impedance of a single panel can drastically effect the overall performance of the string. If it fails sorted not so bad I think but if it fails with increasing resistance, not so good.
Therefore it is best to replace to maintain peak performance.

Right, but wait until performance drops first, right? We don't need to speculate here, he can measure performance and see if/when it starts to deteriorate (which I think it obviously will at some point). If I was him, and I didn't get it replaced on warranty, I'd wait until it starts to actually fail, get the most out of my investment.
 

Online Cyberdragon

  • Super Contributor
  • ***
  • Posts: 2098
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #15 on: December 06, 2015, 05:48:42 am »
If someone wanted to bust his panels they probably would have busted them all. It was probably an accident or birds.
*BZZZZZZAAAAAP*
Voltamort strikes again!
Explodingus - someone who frequently causes accidental explosions
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #16 on: December 06, 2015, 05:50:20 am »
Disclaimer: I'm no expert.

My first thought was a cricket ball.  I also wondered about a golf ball - but I reckon it would have to have been a pretty full-on shot to have enough energy to do that damage.  Also, a golf ball might disappear down a downpipe.

Rocks - yes, but since most rocks aren't of rolling shape, you would expect the culprit to be laying around, unless is skipped off somewhere.


Unless someone has experienced this before and can tell us what has (likely) happened, it will remain a mystery.

I suspect the supplier could give you an answer as it would seem they would be most likely to have come across it before.
 

Online Tomorokoshi

  • Frequent Contributor
  • **
  • Posts: 763
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #17 on: December 06, 2015, 05:57:51 am »
Actually, I think the pattern is very pretty. Kind of a galactic formation or supernova motif.
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 15087
  • Country: za
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #18 on: December 06, 2015, 06:00:37 am »
You can actually repair that panel, using stuff available in Australia and there is an online video about doing so.



If he can do it, and you use his instructions ( really detailed and pretty simple to follow as well) you should be able to get that panel waterproof again before the rain damages it for a pretty low cost.
 

Offline Slothie

  • Regular Contributor
  • *
  • Posts: 63
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #19 on: December 06, 2015, 06:18:55 am »
If you're under a fkight path I'd say a chunk of ice from a plane. If it was a rock, ball etc it would have been in the gutter or on your path. Ice would just melt away.
 

Offline Whales

  • Frequent Contributor
  • **
  • Posts: 839
  • Country: au
    • Halestrom
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #20 on: December 06, 2015, 06:30:30 am »
Tip if this video sounds strange to you: disable one of your speakers.  Somehow the L and R channels have ended up out of phase.

Offline Chris Jones

  • Regular Contributor
  • *
  • Posts: 76
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #21 on: December 06, 2015, 06:35:44 am »
It  might have been worth pointing out to viewers that it's probably not a great idea to go poking the broken parts with one's fingers, if the string of panels is all still connected together. Whilst the safety risks of solar electricity are somewhat over-emphasised in Australia when compared to that nice friendly coal electricity, the string voltage could probably still give you a shock, and in many cases the inverter doesn't float the string with respect to the mains so I wouldn't even go poking the broken panel at night.
 

Offline Phoenix

  • Frequent Contributor
  • **
  • Posts: 291
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #22 on: December 06, 2015, 06:42:21 am »
Out of curiosity does your inverter report the array insulation resistance? I wonder how much this changes with a cracked panel and water ingress...
 

Offline Wytnucls

  • Super Contributor
  • ***
  • Posts: 2836
  • Country: be
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #23 on: December 06, 2015, 06:51:05 am »
Meteorite damage is not uncommon. Certainly more likely than ice or metal bits falling off airplanes. Meteorites are sought after, so any chunk that survived the impact might be worth looking for.

http://www.redding.com/news/unidentified-object-from-sky-destroys-car-in
 

Online TheSteve

  • Supporter
  • ****
  • Posts: 2986
  • Country: ca
  • GHz
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #24 on: December 06, 2015, 07:05:59 am »
What games do your neighbors usually play in their backyard?
VE7FM
 

Offline Halcyon

  • Super Contributor
  • ***
  • Posts: 3637
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #25 on: December 06, 2015, 08:15:41 am »
If there is no signs of a ball or other obvious object in your yard which could have caused the damage, another idea might be someone was actually on your roof (trying to break in) and stepped on it. Break-ins via roof tiles aren't totally unheard of. As Klomderper has already suggested, CCTV isn't a bad idea. You should be able to pick up some second hand professional POE cameras for a reasonable price.
I'm not suggesting you stick one on your roof, but it's quite easy to jump up on Colourbond fences to gain access to the roof.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29650
  • Country: au
    • EEVblog
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #26 on: December 06, 2015, 08:26:37 am »
If there is no signs of a ball or other obvious object in your yard which could have caused the damage, another idea might be someone was actually on your roof (trying to break in) and stepped on it.

Absolutely no way that damage is caused by someone stepping on it.
 

Offline con-f-use

  • Supporter
  • ****
  • Posts: 802
  • Country: at
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #27 on: December 06, 2015, 08:50:19 am »
Doesn't your home insurance cover weather damage?
 

Offline PinheadBE

  • Regular Contributor
  • *
  • Posts: 64
  • Country: be
  • Pinball Freak
    • The Belgian Pinball Forum
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #28 on: December 06, 2015, 09:10:05 am »
Did you have bad weather recently?  If so, it could be a shark....
https://youtu.be/6S5Jus9VLKA
 :-DD

No, seriously: Look how the panel seems to be bent inwards.   This is not a golf ball or whatever.
Besides, the impact looks very round shaped, so the angle should be near 90°, meaning free fall.

My best guest would be a tiny meteor, or a metal piece fallen from an airplane.

Just my 2c
« Last Edit: December 06, 2015, 09:24:56 am by PinheadBE »
The Belgian Pinball Forum: http://ericpinballforum.be/
Please keep our planet clean
 

Online Psi

  • Super Contributor
  • ***
  • Posts: 7279
  • Country: nz
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #29 on: December 06, 2015, 09:14:26 am »
Most likely is just a ball of some sort and the person came onto the property and retrieved their ball after it rolled off the roof.

Meteorites come in very hot, you always find things melted/charred nearby

Something falling from a plane is possible, but pretty unlikely.

The impact looks like it involved quite a large amount of force. So i'm thinking a hard ball (cricket, golf), that was hit almost vertical from the property on either side, or from the street.
A potato gun is also a possibility but i would have expected potato fragments on the roof. I suppose if it happened long ago it might have decomposed and been washed away by rain.

« Last Edit: December 06, 2015, 09:23:10 am by Psi »
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline jitter

  • Frequent Contributor
  • **
  • Posts: 804
  • Country: nl
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #30 on: December 06, 2015, 09:22:09 am »
IMHO, it wasn't caused by something coming from below, like a golf ball. I can't imagine that it could have acquired enough energy to do damage like that, especially if it were coming in under less than a perfect straight angle. Angles shallower than 90 degrees probably would have caused it to skip off.

IMO, hail seems the most likely cause. If you're hit by a freak hail storm, there's hail stones coming down the size of tennis balls and bigger.
These get quite a lot of energy because they get the time to accelerate when they fall to earth and all of that energy is released during impact.

The impact site on your panel looks peculiar. The "crater" seems to have a hill with the top right in the centre. I wondered why that had happened and came up with this theory: a big hail stone hits the panel with tremendous force and since it's round the point of impact is tiny, at first. This pins down the glass at that point against the solar cells. As the impact progresses, the ice crushes and the contact area becomes bigger, so the force on the glass around the centre doesn't pin it down anymore and it can be hurled away. A fraction later, the energy released melts the ice and suddenly, the hail stone cannot break the glass anymore, hence the nice round shape of the impact. When the impact is almost over, the pressure on the centre releases and the energy dissipates, having not enough force to expell the glass, leaving this "hill".

It came as a surprise to you, so the impact might have happened while you were away. But it might have happened while you were home. Among the thousands of hail stones hitting the panels, there may only have been one with enough energy to shatter the glass.

Youtube is riddled with freak hail storm clips from all around the world. The one that is printed in my memory is from somewhere in Germany where a freak hail storm destroys tough ceramic roof tiles that might have been on that roof for many decades. I'll try to find it and post a link.
Edit: not the one I was looking for but even better:



I was wondering if hail storms ever hit Sydney after I had written this and did a quick search... oh yeah, they do indeed...
« Last Edit: December 06, 2015, 09:42:22 am by jitter »
 

Offline crispy_tofu

  • Super Contributor
  • ***
  • Posts: 1124
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #31 on: December 06, 2015, 09:54:34 am »
Doesn't your home insurance cover weather damage?
But was it caused by the weather?
 

Offline Artlav

  • Frequent Contributor
  • **
  • Posts: 744
  • Country: ru
    • Orbital Designs
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #32 on: December 06, 2015, 10:02:11 am »
Meteorites come in very hot, you always find things melted/charred nearby
Actually, no.
If a meteorite was hot enough to char anything by the time it hit the ground, this would have made international news to the effect of "a meteor impact wiped out a neighborhood in Sydney".

Small (under a few tonnes) meteorites are already falling at terminal velocity as high as airplane height, and by the time they hit the ground they are long since metal-cold.

The famous Chelyabinsk meteor's main chunk was going at terminal velocity near the ground, and it was large enough to poke a big hole in the ice of the lake:


And that's with a 500 kiloton worth of a meteor.
Hacking the universe since 2008
Having a life since 2013
 

Offline G7PSK

  • Super Contributor
  • ***
  • Posts: 3642
  • Country: gb
  • It is hot until proved not.
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #33 on: December 06, 2015, 10:08:46 am »
What ever hit that panel was fairly small only a mm or two in diameter. Check for a small hole in the middle  most of the damage is due to shock waves.
 

Offline kaz911

  • Frequent Contributor
  • **
  • Posts: 817
  • Country: gb
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #34 on: December 06, 2015, 10:13:55 am »
My bet is a Delivery guy - with a test power supply from Siglent.

http://www.birminghammail.co.uk/news/midlands-news/sorry-your-parcel-roof-yodel-10485972

... it does happen ...

so are you missing any parcels ?
 

Offline FireFlower

  • Regular Contributor
  • *
  • Posts: 129
  • Country: fi
  • Wish had a cabin in Lappland
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #35 on: December 06, 2015, 10:35:54 am »
My theory:


Why you didn't find proof would mean the turtle or similar survived impact and bird took its prey to drop it again elsewhere.
 

Offline RodG

  • Newbie
  • Posts: 4
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #36 on: December 06, 2015, 11:21:29 am »
Had a (stray?) home-made concrete projectile break my tile a few years ago. I assume it's from a air-cannon some kids had made up. Look around and see if you can find something similar.
 

Offline PE1RKI

  • Regular Contributor
  • *
  • Posts: 94
  • Country: nl
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #37 on: December 06, 2015, 12:03:14 pm »
maybe the thing that fell on it is still in your garden or left traces in the sand when it fell of the roof.
 

Offline mikeselectricstuff

  • Super Contributor
  • ***
  • Posts: 11992
  • Country: gb
    • Mike's Electric Stuff
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #38 on: December 06, 2015, 12:15:49 pm »
As it's toughened glass, I wonder if it could have been a latent manufacturing defect that popped due to normal thermal cycling. 
Youtube channel:Taking wierd stuff apart. Very apart.
Mike's Electric Stuff: High voltage, vintage electronics etc.
Day Job: Mostly LEDs
 

Offline ornea

  • Supporter
  • ****
  • Posts: 107
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #39 on: December 06, 2015, 12:19:40 pm »
Still curious if there is any debris in the gutter.

Perhaps Dave could get the panel under the scope and look for fragments of rock, balls etc.

Unless it has rained recently there should be something detectable unless it was ice.
 

Offline zoltan

  • Contributor
  • Posts: 35
  • Country: hr
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #40 on: December 06, 2015, 12:25:32 pm »
Maybe hail with metal core? You have a bent nail next to the panel. (@3:37).
Strong wind can easily pick up something like that, and later in the clouds it act as a solid core to form deadly hail.


Could you take that nail under microscope? One end should have some visible damage if it is a culprit
 

Offline Ian.M

  • Super Contributor
  • ***
  • Posts: 7995
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #41 on: December 06, 2015, 12:27:32 pm »
If Dave's place is under a flightpath, https://en.wikipedia.org/wiki/Blue_ice_(precipitation)
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29650
  • Country: au
    • EEVblog
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #42 on: December 06, 2015, 12:30:20 pm »
If Dave's place is under a flightpath, https://en.wikipedia.org/wiki/Blue_ice_(precipitation)

Less than 500m offset from one.
 

Offline PE1RKI

  • Regular Contributor
  • *
  • Posts: 94
  • Country: nl
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #43 on: December 06, 2015, 12:33:08 pm »
in the video you can see a round dent in the center. something round and heavy fell with on it at high speed.
a nail or golf ball dont have the mass to do this kind of damage.
i say it was a big chunk of ice or a baseball or a meteorite. baseball might have been retrieved, ice melts and a meteorite can blend into the garden.
if something fell out of a plane, it must still be around the house. the glass broke in such a way that i dont beleive it can bounce far away.
more like a "thud" sound and then rolled of the roof.
 

Offline Rasz

  • Super Contributor
  • ***
  • Posts: 2273
  • Country: 00
    • My random blog.
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #44 on: December 06, 2015, 12:55:32 pm »
looks like golf ball


https://www.solarpaneltalk.com/forum/solar-panels-for-home/solar-panels-for-your-home/19787-golf-ball-damage-protection

that Epoxy resin looks interesting, I wouldnt necessary import overpriced stuff from US, but investigating locally obtainable UV resistant substitute could be a viable fix on the cheap. It will fix refractions caused by cracks and protect from moisture.
Who logs in to gdm? Not I, said the duck.
My fireplace is on fire, but in all the wrong places.
 

Offline zoltan

  • Contributor
  • Posts: 35
  • Country: hr
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #45 on: December 06, 2015, 12:56:06 pm »
As it's toughened glass, I wonder if it could have been a latent manufacturing defect that popped due to normal thermal cycling.
This summer I had a broken rear windshield on my car. It was in "one piece" until I noticed the rear window is strange "milky" looking and stopped the car. Then the kinetic energy just shattered it to pieces. Nothing was found inside, and the glass had no impact signs.

Dave's panel has a clear impact point, while it could be manufacturing defect, it has to be combined with impact. And there is a large nail under the next panel, if frozen inside hail ball it could pierce the glass on impact.
 

Offline bitwelder

  • Frequent Contributor
  • **
  • Posts: 813
  • Country: fi
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #46 on: December 06, 2015, 12:57:13 pm »
Also, no clue *when* it might have happened?
As I understand, no drop in produced power and nobody heard the noise of the shattered glass (and/or the impact with the unknown object), so last datapoint in time is when Dave has previously inspected the panels?
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #47 on: December 06, 2015, 01:11:39 pm »
Sometimes I like diagrams ... and I was curious about the impact damage, so I looked through the video a couple of times to try and make out what broke where.

This is my best guess... (BTW when I say 'panel' I mean the protective glass panel, nothing else.)



The centre white zone I am calling the crush zone and I suspect it might be rounded to match the shape of the object at the point it struck the panel.  I've used a cricket ball as a suggestion (you'll find more of these than baseballs around Australia), but the object needn't be spherical.  I would not exclude a freakishly large piece of hail.

As the object first hit the glass, the point of contact would have failed, causing the panel wide cracking to begin. As it progressed, more surface area of the object came into direct contact with the glass which caused high density cracking, resulting in the white centre and the crater shape.

As the object penetrated further, the area of glass around the object would have been trying to bend down.  As the object transferred more of its energy to the glass, the pressure increased to the point where a shear failure occurred  (if I got that term wrong, I apologise) causing the white ring out from the crush zone - which I think has a step as I have put in my diagram.  I suspect the location of the shear failure ring will be a function of a leverage component in the bending down action mentioned above.

All the other cracking over the panel just appears to be the typical result of tempered glass failure.

Also, upon mulling it over, I don't believe something the size of a golf ball would create the damage shown.  Yes, a golf ball might shatter the panel, but if so, I think the 'fingerprint' would be much smaller.  Likewise, I don't believe it was a sharp-pointed object.  Yes, a sharp pointed object could find a point of weakness that shatters the panel, but I can't see how it would leave that 'crush zone'.

If the 'crush zone' is rounded and you can get some sort of measurement on the curvature, you might be able to work out a rough diameter of the offending object.


Anyway, there's my thoughts on the matter.

Shoot away - I'll just duck.
 

Offline Rasz

  • Super Contributor
  • ***
  • Posts: 2273
  • Country: 00
    • My random blog.
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #48 on: December 06, 2015, 01:51:23 pm »
I don't believe something the size of a golf ball would create the damage shown.

https://www.solarpaneltalk.com/filedata/fetch?id=284412&d=1432502496
Who logs in to gdm? Not I, said the duck.
My fireplace is on fire, but in all the wrong places.
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #49 on: December 06, 2015, 02:48:44 pm »
That is really close to Dave's experience and it proves that kind of damage is possible.  However, based on the apparent diameter of the 'crater' (which I'm guessing from other elements in the photos) that example actually reinforces my thoughts that it wasn't a golf ball in Dave's case.

I know it's a bit of a reach without some real measurements - but that's the impression I get.

Maybe Dave could take a couple of balls up on the roof and see if there is one that fits the crater.
 

Offline Ian.M

  • Super Contributor
  • ***
  • Posts: 7995
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #50 on: December 06, 2015, 03:15:01 pm »
The other issue is: how would a ball end up hitting the roof at a high enough angle to cause symmetrical impact damage? 

Its unlikely to have been a high angle golf or cricket ball, as Dave hasn't commented about neighbours kids frequently needing to retrieve balls.  NSW bans hunting catapults etc., and I believe Dave's in a nice enough area that there is a very low probability of it being a ball bearing hit from a slingshot fired near vertically or of some idiot firing a firearm vertically.   In the UK there is always a risk of damage around Guy Fawkes night from rocket sticks and the metal rocket bodies from illegally fired marine parachute flares, but Australia doesn't celebrate  Guy Fawkes night and the sale of fireworks to the general public is mostly banned, largely due to the risk of bush fires, and no such object was found. There are no traces of broken mussel or snail shells, and Australia doesn't have any indigenous tortoises, so a bird dropping their prey to crack its shell theory is also highly unlikely

Its therefore most probably ice impact damage - either a freak hailstone that may have been much larger than others in the same storm, or ice falling from an aircraft.

@Dave (EEVBlog):  Do you remember any bad hail storms since the previous time you were on the roof?
« Last Edit: December 06, 2015, 03:17:04 pm by Ian.M »
 

Offline gilbenl

  • Regular Contributor
  • *
  • Posts: 170
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #51 on: December 06, 2015, 03:19:09 pm »
I'd bet my left foot on a cricket or baseball. I also noticed that it appears your fence/neighbors are about 1.5m away from the edge of your roof. There's also a pool within arm/bat's reach as well. Its entirely conceivable that some kids were playing catch or actually hitting balls, one went up on a high arc and came down on your panel. It then rolled and took a hop off the edge of the panel itself or those terra cotta roof tiles and landed back in their yard. They retrieved it and never thought twice...

Golf ball also seems reasonable. Although small, they deform a good bit (relatively) on impact and making the crater somewhat larger than expected. You don't need to be anywhere near a golf course to see errant golf balls either. I had a friend whose windshield was shattered by one. He knew the source was a golf ball because he found it sitting on his wiper. Turns out a neighbor was hitting balls into one of those practice nets using a wedge, was set up too far back, the arc of the ball missed the net and traveled 50 or so yards to meet my buddy's windshield.

The video below shows the impact deformation of a moving golf ball on a flat surface (vs. impact leaving the club face), however, this ball was probably moving considerably faster than anything you'd encounter. It does well highlighting just how much deformation capacity/elasticity a golf ball can exhibit without breaking. Okay, it may just be a cool video, too.

https://www.youtube.com/embed/HTgSaEPdj-U
What doesn't kill you, probably hurts a lot.
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #52 on: December 06, 2015, 03:29:15 pm »
I wasn't expecting THAT amount of deformation!

Is that a regular golf ball?  I would have expected the case to crack deforming that much.
 

Offline gildasd

  • Frequent Contributor
  • **
  • Posts: 926
  • Country: be
  • Engineering watch officer - Apprentice Officer
    • Sci-fi Meanderings
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #53 on: December 06, 2015, 03:55:27 pm »
Aliens and magnets, especially magnets.

But seriously folks, when I was about 10, someone did manage to whack a cricket ball that endded in the windshield of the old school Land Rover of one of the teachers.
With only one bounce.
The flat glass had a plastic film on the back side.
The end result was near identical to Dave's panel.
I'm electronically illiterate
 

Offline Rasz

  • Super Contributor
  • ***
  • Posts: 2273
  • Country: 00
    • My random blog.
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #54 on: December 06, 2015, 04:20:44 pm »
Maybe Dave could take a couple of balls up on the roof and see if there is one that fits the crater.

I dont think Dave has the balls to do it, he is not a golfer.
Who logs in to gdm? Not I, said the duck.
My fireplace is on fire, but in all the wrong places.
 

Online blueskull

  • Supporter
  • ****
  • Posts: 12272
  • Country: cn
  • Power Electronics Guy
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #55 on: December 06, 2015, 04:37:04 pm »
Could it be an ice ball? Solid, hard cored ice balls falling from sky are powerful enough to shatter the panel.

Also, fix it or replace it before a heavy rain, or the panel could electrolysis itself, and render it unrepairable, if its internal bus bars are not properly potted in epoxy or silicone.
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 15087
  • Country: za
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #56 on: December 06, 2015, 04:44:14 pm »
Years ago I did see that a hard boiled egg ( boiled to Mil spec ie boil till the white and yolk are blue) is capable of breaking a windscreen when it hits it at 100kph.

As to the golf ball, you do accelerate it from zero to 200kph in it's own diameter, so yes it has to deform a lot and survive that. Drive a tank over one and it does survive, though you may have to look for where it went when it popped out under the tread.

They do not survive going through a jet turbine, though the turbine is supremely unaffected by the operation. It has to survive FOD on the runway ( small stones, errant small birds, national flowers) without incident. Geese and larger birds do tend to do damage, look at those nice RR Trent videos on YT for the aftermath.

We had quite a few engines that ingested pigeons during operation, engine makes a small puff of smoke and there is no evidence aside from a few smears of blood of the bird. Even saw one that had a first stage compressor blade snap off from a bird strike, and go through the engine without any sign aside from greatly increased vibration, which went away with increased power, so the 50 minute leisurely ferry flight went down to 15 minutes at full afterburner, where it was almost gone. Came in hot, and ran out of fuel during touch down, so had to be towed off the runway. Luckily it was off for an airframe overhaul, so the engine was coming out in any case, though it came back as cargo to the service bay for investigation and overhaul.
 

Offline RupertGo

  • Regular Contributor
  • *
  • Posts: 77
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #57 on: December 06, 2015, 04:58:46 pm »
Here's another link to suspected meteorite damage to a PV panel - http://www.solarcurator.com/2012/06/13/module-failure-from-an-otherworldly-source/. Of particular interest, they found the contender for the crime by running a magnet around the area.

But I'd suspect a well-hooked cricket ball, from the shape and size of the depression. A decent swing plus contact can add a lot of energy and height, and the perpetrator will be keen to remove the evidence. A solitary huge hailstone sounds unlikey; that sort of hailstorm tends to get noticed. My favoured secondary explanation would be something falling from an aircraft, especially if you're in the area where the gear might be coming down prior to landing.

 

Offline max_torque

  • Super Contributor
  • ***
  • Posts: 1030
  • Country: gb
    • bitdynamics
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #58 on: December 06, 2015, 05:51:38 pm »
Would some form of thin, self adhesive, transparent stick on film not be ideal for a temporary fix?

Like the stuff you use to laminate paper with etc?


I'm also pretty sure that any ball that hit that panel would bounce off and go a long way, so it ain't going to be found in the gutter or probably even in the garden!
 

Offline vodka

  • Frequent Contributor
  • **
  • Posts: 456
  • Country: es
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #59 on: December 06, 2015, 05:56:58 pm »
I see the deformation of the panel solar, and it is almost perforated.
I believe that the projectile  (steel ball or baseball ball)path  seems as anti-tank gun, a horizontal with lightness parabolic path with an impact at high speed .
This can to explain the great deformation and the place where could be thrown(Somebody have  a building a few more elevated than Dave's home).
I suspect that somebody was doing out of the ordinary in the roof
 

Offline Ian.M

  • Super Contributor
  • ***
  • Posts: 7995
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #60 on: December 06, 2015, 06:24:56 pm »
Its definitely a good idea to make it weather-tight to maintain the system output while the manufacturer and the insurers argue about who pays how much. Get lots of photos first.  I'd say the easiest would be heavy grade clear PVC, foil taped to the rim.  I'd avoid anything stick-down to the panel itself as putting pressure on it in that condition isn't a good idea, and also the weatherproofing needs to be easily removable in case the manufacturer wants to examine it.
 

Offline l0rd_hex

  • Regular Contributor
  • *
  • Posts: 53
  • Country: ca
  • I'm a master of karate and friendship for everyone
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #61 on: December 06, 2015, 07:22:00 pm »
Have you ruled out terrorism? I'm thinking para-militarized llamas armed with frozen burrito cannons. I am deadly serious about this.
"I haven't paid taxes in six years, and I'm not getting busted by a damn sandwich." - Benjamin Franklin
 

Offline MartinX

  • Regular Contributor
  • *
  • Posts: 108
  • Country: se
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #62 on: December 06, 2015, 08:17:49 pm »
Drunken golfers did this.
 

Offline Kleinstein

  • Super Contributor
  • ***
  • Posts: 6206
  • Country: de
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #63 on: December 06, 2015, 10:03:16 pm »
A meteorite is rather heavy material with a high speed. This would likely give smaller impact zone and less of the big dent.
Comparing this with the damage shown from the golf ball in the other video, I would get its somthing like the cricket ball of a block of ice of similar size.

Also note the rather concentric rings around the impact. So likely the impact was rather vertical.
 

Offline Ian.M

  • Super Contributor
  • ***
  • Posts: 7995
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #64 on: December 06, 2015, 10:27:09 pm »
Have you ruled out terrorism? I'm thinking para-militarized llamas armed with frozen burrito cannons. I am deadly serious about this.
More likely Australian DSTO's combat kangaroos armed with beachballs!
http://baetzler.de/humor/killer_kangaroo.html
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29650
  • Country: au
    • EEVblog
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #65 on: December 06, 2015, 10:40:07 pm »
Have you ruled out terrorism? I'm thinking para-militarized llamas armed with frozen burrito cannons. I am deadly serious about this.

It can't be ruled out.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29650
  • Country: au
    • EEVblog
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #66 on: December 06, 2015, 10:41:51 pm »
My favoured secondary explanation would be something falling from an aircraft, especially if you're in the area where the gear might be coming down prior to landing.

30km out from the airport.
But am within a few hundred meters of a flight path.
 

Offline Ian.M

  • Super Contributor
  • ***
  • Posts: 7995
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #67 on: December 06, 2015, 10:51:14 pm »
If my numbers are right, that means the aircraft are at about 5000' - 6000' when they fly over you, which would be consitent with ice buildups having thawed long enough to break loose.  As the aluminium aircraft skin conducts heat far better than ice does, thick buildups tend to break free rather than thaw completely.
.
See: http://www.engineeringtoolbox.com/air-altitude-temperature-d_461.html
« Last Edit: December 06, 2015, 10:55:47 pm by Ian.M »
 

Offline chickenHeadKnob

  • Frequent Contributor
  • **
  • Posts: 801
  • Country: ca
  • doofus programus semi-retiredae
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #68 on: December 07, 2015, 01:51:27 am »
My favoured secondary explanation would be something falling from an aircraft, especially if you're in the area where the gear might be coming down prior to landing.

30km out from the airport.
But am within a few hundred meters of a flight path.
Ha - ha (sorry) blue ice it is! I know you like to sniff things now is the chance for forensic schnuffery. If this is recent damage the crater may still have the fragrance of blue sanitizer+human waste. On the other hand if it has been a-while and there have been rains...

A damaged solar panel would be getting of lightly. Some twenty years ago a decrepit ancient DC-7, a four engined  prop plane , lost a nose wheel and it went through the roof of an apartment building near where I used to live.
 

Offline cdev

  • Super Contributor
  • ***
  • Posts: 5082
  • Country: 00
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #69 on: December 07, 2015, 02:19:09 am »
Once I saw a coated, "shatterproof" (tinted) glass door spontaneously shatter (but of course, the coating meant it did not explode it simply became a mess of shattered glass) because it was in full sunlight and the sun must have caused some kind of catastrophic failure due to unequal heating of the laminated materials.

It was really quite spectacular. The entire thing turned into a mess of cracks in around half a second. Nobody was anywhere near it and it was shut. It was fun because I was with a bunch of scientists. We were all left awestruck by this event.

It did make a funny kind of sound.
"What the large print giveth, the small print taketh away."
 

Offline aroby

  • Regular Contributor
  • *
  • Posts: 206
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #70 on: December 07, 2015, 02:45:18 am »
Maybe an Amazon drone on a test flight dropped its package too soon ...
 

Offline Smokey

  • Super Contributor
  • ***
  • Posts: 1582
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #71 on: December 07, 2015, 03:43:34 am »
Cricket ball?  Really?  It would essentially have to come from your close neighbors right?  Do you have a cricket playing neighbor that is such a dick that he would carelessly launch a ball out of his yard, crack your solar panel, and not own up to it?  A professional baseball home run is like 450 feet (137m).  I'm not sure how far cricket balls go, but that really limits the range it could have come from (and you pretty much know the direction).
Assuming it was a cricket ball, the damage and angle would look to me that someone was seriously trying to wack the crap out of the cricket ball, not just casually toss it over a fence.  Is that realistic? 

I don't know what neighborhood you live in, but I would hate to be looking over my shoulder for all these roving bands of cricket hooligans all the time.

« Last Edit: December 07, 2015, 03:46:04 am by Smokey »
 

Offline Circlotron

  • Super Contributor
  • ***
  • Posts: 1608
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #72 on: December 07, 2015, 03:46:10 am »
Light is photons.
Photons have properties of both waves and particles.
Radio waves are electromagnetic, just like light.
Your local radio station sends electromagnetic waves.
Maybe their antenna was emitting waves and *heavy rock* particles through your property at the time?
 

Offline DrGeoff

  • Frequent Contributor
  • **
  • Posts: 709
  • Country: au
    • AXT Systems
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #73 on: December 07, 2015, 04:07:08 am »
Cricket ball?  Really? 

Of course. Cricket balls are harder than baseballs.
Then some kid with a tennis racquet could have whacked a golf ball up in the air (now that really flies) or a rock in the air (and probably lost a string doing that) which could come down onto a panel. A golf ball would bounce away and down the street.
Was it really supposed to do that?
 

Offline Smokey

  • Super Contributor
  • ***
  • Posts: 1582
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #74 on: December 07, 2015, 04:17:54 am »
I get what a cricket ball is.  My point was that if that was what it was, it couldn't have come from very far away.  That side of his house doesn't look like it faces the street.  Since you essentially know the direction, and you (probably) know who your neighbors are in that direction, what is the likelihood that one of those neighbors is a dick or has dick kids.

If we are talking golf balls, the average golf drive is 200 yards (182m) so look for dick neighbors that far out.
 

Offline Alexei.Polkhanov

  • Frequent Contributor
  • **
  • Posts: 683
  • Country: ca
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #75 on: December 07, 2015, 04:32:36 am »
My bet is on a golf ball. I am waiting for another episode of Myth Busters, "can golf ball do that?" :) Dave still have enough panels to test all plausible theories:

Here is the Poll:
ice - 0 votes
golf ball - 1 vote
baseball/cricket ball - 0
meteorite (hard to simulate?) - 0 votes
birds - 0 votes
 


Offline DrGeoff

  • Frequent Contributor
  • **
  • Posts: 709
  • Country: au
    • AXT Systems
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #77 on: December 07, 2015, 04:41:34 am »
I get what a cricket ball is.  My point was that if that was what it was, it couldn't have come from very far away.  That side of his house doesn't look like it faces the street.  Since you essentially know the direction, and you (probably) know who your neighbors are in that direction, what is the likelihood that one of those neighbors is a dick or has dick kids.

If we are talking golf balls, the average golf drive is 200 yards (182m) so look for dick neighbors that far out.

A lot of high school kids are finished now and roaming about. It does not have to be a neighbour, just some kids wandering around the streets.
Was it really supposed to do that?
 

Online Cyberdragon

  • Super Contributor
  • ***
  • Posts: 2098
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #78 on: December 07, 2015, 04:41:52 am »
My bet is on a golf ball. I am waiting for another episode of Myth Busters, "can golf ball do that?" :)
I think Mythbusters got cancelled. :( Do they even play much golf in Australia?
*BZZZZZZAAAAAP*
Voltamort strikes again!
Explodingus - someone who frequently causes accidental explosions
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #79 on: December 07, 2015, 04:47:02 am »
Yes, golf is a popular sport here in Australia.  I don't know the actual figures, but the impression I get is that it is something similar to that of the USA, probably a bit less.

Errant golf balls aren't common, but you can't rule out an idiot with no conscience.
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #80 on: December 07, 2015, 04:51:21 am »
My bet is on a golf ball. I am waiting for another episode of Myth Busters, "can golf ball do that?" :) Dave still have enough panels to test all plausible theories:

Here is the Poll:
ice - 0 votes
golf ball - 1 vote
baseball/cricket ball - 0
meteorite (hard to simulate?) - 0 votes
birds - 0 votes

Put me down for a cricket ball.

... and if it is a cricket ball that did the damage, I would be looking within a 100m radius.  Considering the symmetry of the damage, I agree with others that the trajectory will have been around the perpendicular.  To do that and have the necessary velocity, would mean a solid whack and a skied skyed ball.
« Last Edit: December 07, 2015, 11:31:56 am by Brumby »
 

Offline pickle9000

  • Super Contributor
  • ***
  • Posts: 2132
  • Country: ca
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #81 on: December 07, 2015, 05:00:20 am »
I say it's a dragonball because they can disappear.
 

Offline Smokey

  • Super Contributor
  • ***
  • Posts: 1582
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #82 on: December 07, 2015, 05:04:05 am »
So the cricket ball was hit from the grassy knoll and made of ice so there was no cricket ball evidence left over?  Are you sure it wasn't the Cubans?  When is the Oliver Stone move coming out?
 :-//
 

Offline DimitriP

  • Super Contributor
  • ***
  • Posts: 1017
  • Country: us
  • "Best practices" are best not practiced.© Dimitri
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #83 on: December 07, 2015, 05:10:26 am »
The ripples don't look perfectly concentric. I think that's a clue as to the object's direction. 


   If three 100  Ohm resistors are connected in parallel, and in series with a 200 Ohm resistor, how many resistors do you have? 
 

Offline Ian.M

  • Super Contributor
  • ***
  • Posts: 7995
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #84 on: December 07, 2015, 05:25:29 am »
The roof is sloped, which if we assume an impact that was closer to being perpendicular to the surface than to being glancing, offsets the possible origin zone.  Probably within 50m the other side of the house and maybe 150m that side.
 

Online Psi

  • Super Contributor
  • ***
  • Posts: 7279
  • Country: nz
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #85 on: December 07, 2015, 06:05:30 am »
I wonder if the object might have bounced and then rolled under the panel.
Might be worth a look under it
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline LabSpokane

  • Super Contributor
  • ***
  • Posts: 1899
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #86 on: December 07, 2015, 06:31:59 am »
I'm glad it wasn't anything as simple as some kid chucking a rock at a piece of glass to see if it would break.

Because what really happened is the panel was damaged by falling debris from a test of my homemade anti-satellite weapon.  If you find any chunks of titanium with Chinese writing on them, just keep it our little secret, OK?
 

Offline pickle9000

  • Super Contributor
  • ***
  • Posts: 2132
  • Country: ca
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #87 on: December 07, 2015, 06:50:39 am »
I'm glad it wasn't anything as simple as some kid chucking a rock at a piece of glass to see if it would break.

Because what really happened is the panel was damaged by falling debris from a test of my homemade anti-satellite weapon.  If you find any chunks of titanium with Chinese writing on them, just keep it our little secret, OK?

Awesome, best one so far. Honorable mention to Smokey, Cubans = Awesome.
 

Offline marber

  • Regular Contributor
  • *
  • Posts: 55
  • Country: nl
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #88 on: December 07, 2015, 09:08:49 am »
I think Batteriser's shipment of Fail has arrived... ;-) The EE equivalent of a dead horse head perhaps? ;)
 

Offline GNU_Ninja

  • Regular Contributor
  • *
  • Posts: 200
  • Country: gb
  • Mostly Harmless
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #89 on: December 07, 2015, 09:20:25 am »
Interesting stuff ... http://etheses.bham.ac.uk/4263/1/Chen-X13PhD.pdf

Forensic fracture analysis: https://www.ncjrs.gov/pdffiles1/nij/grants/241445.pdf

My moneys on a cricket ball  :)
« Last Edit: December 07, 2015, 09:48:29 am by GNU_Ninja »
 

Offline Muttley Snickers

  • Supporter
  • ****
  • Posts: 1970
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #90 on: December 07, 2015, 10:07:44 am »
Skylab..... :popcorn:

Although a big pain in the arse having  a panel smashed it's probably better for that to have occurred rather than whatever caused the impact breaking a roof tile and causing flooding to part of the house during the next severe rain storm, could have happened I suppose, it got close anyhow.

« Last Edit: December 07, 2015, 10:34:04 am by Muttley Snickers »
 

Offline VK3DRB

  • Super Contributor
  • ***
  • Posts: 1483
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #91 on: December 07, 2015, 11:05:08 am »
Looks like a misplaced cricket ball or golf ball landed on your roof.

Remember LG = Lucky if it Goes :)

LG = Lucky Goldstar. That is their real name. The same makers of the crappy Goldstar video recorders and a host of other low end (or "no" end) rubbish dumped into places like K-Mart, and with some models, no spare parts available from anywhere. Even Goldstar's component placement machines were toys compared to the beautifully engineered Japanese workhorses, like Juki.

Sorry to disappoint, but Dave's Lucky Goldstar panels are low end.

Goldstar is synonymous with crap.



 

Offline DenzilPenberthy

  • Frequent Contributor
  • **
  • Posts: 332
  • Country: gb
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #92 on: December 07, 2015, 01:14:35 pm »
I'm going to put in another vote for a cricket ball fired from the grassy knoll next-door. I'm sure it wasn't done on purpose but I remember as a kid if you smash someone's greenhouse with a ball you crap your pants, hide the ball and say you were playing indoors all day :)
 

Offline Ian.M

  • Super Contributor
  • ***
  • Posts: 7995
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #93 on: December 07, 2015, 01:39:04 pm »
It would be interesting to know the maximum hail stone size that the panel is rated to withstand.   The density of ice is 0.9340 g/ml and of a golf ball is about 1.15 g/mL.   A  golf ball is 42.7 mm diameter, weighs less than 45.93g i.e less than a 46mm diameter sphere of ice and at terminal velocity should not be capable of breaking a panel that can withstand 46mm hail stones. 

As large hailstones are not uncommon in the Sidney area, I would argue that any panel designed for unprotected outdoor installation that cannot withstand a 50mm hailstone at terminal velocity is not of merchantable quality.

http://www.bom.gov.au/nsw/sevwx/hailfact.shtml
 

Offline zapta

  • Super Contributor
  • ***
  • Posts: 6004
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #94 on: December 07, 2015, 01:57:23 pm »
My money's on a cricket ball.  ;)

It was causes by climate change.
Drain the swamp.
 

Offline jancumps

  • Supporter
  • ****
  • Posts: 1203
  • Country: be
  • New Low
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #95 on: December 07, 2015, 02:49:20 pm »
Lightning?
 

Offline nixfu

  • Supporter
  • ****
  • Posts: 343
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #96 on: December 07, 2015, 02:53:32 pm »
Obviously giant aussie spider related damage.
 

Offline Wytnucls

  • Super Contributor
  • ***
  • Posts: 2836
  • Country: be
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #97 on: December 07, 2015, 02:57:12 pm »
Does a soprano live next door?

« Last Edit: December 07, 2015, 03:03:55 pm by Wytnucls »
 

Offline GNU_Ninja

  • Regular Contributor
  • *
  • Posts: 200
  • Country: gb
  • Mostly Harmless
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #98 on: December 07, 2015, 03:10:21 pm »
Does a soprano live next door?



I think Dave might have noticed  :-DD
« Last Edit: December 07, 2015, 03:42:21 pm by GNU_Ninja »
 

Offline zapta

  • Super Contributor
  • ***
  • Posts: 6004
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #99 on: December 07, 2015, 03:48:57 pm »
Does a soprano live next door?

... or a uBeam lab?
Drain the swamp.
 

Offline warp_foo

  • Supporter
  • ****
  • Posts: 117
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #100 on: December 07, 2015, 04:06:33 pm »
My bet is on a golf ball. I am waiting for another episode of Myth Busters, "can golf ball do that?" :)
I think Mythbusters got cancelled. :( Do they even play much golf in Australia?

There will be one final season in 2016. 8 or 10 episodes, I think.

m
Where are we going, and why are we in a handbasket?
 

Offline NANDBlog

  • Super Contributor
  • ***
  • Posts: 4428
  • Country: nl
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #101 on: December 07, 2015, 06:38:09 pm »
I think it was the invading army of the G'Gugvuntts or the Vl'hurgs testing their super-weapon on your massive scale energy collector mega complex.

Quote
"After millennia of battle the surviving G'Gugvuntt and Vl'hurg realised what had actually happened, and joined forces to attack the Milky Way in retaliation. They crossed vast reaches of space in a journey lasting thousands of years before reaching their target where they attacked the first planet they encountered, Earth. Due to a terrible miscalculation of scale the entire battle fleet was swallowed by a small dog. The Hitchhiker's Guide to the Galaxy states that this sort of thing happens all the time."
 

Offline jnissen

  • Regular Contributor
  • *
  • Posts: 61
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #102 on: December 07, 2015, 06:53:07 pm »
I wasn't expecting THAT amount of deformation!

Is that a regular golf ball?  I would have expected the case to crack deforming that much.

That is not a normal hit on the ball. Look again at Youtube and there are a lot of golf hit slow motion video's. Nothing comes close to the compression initially shown.

BTW - I will also vote for a cricket/baseball type of hit. As a kid I can recall playing croquet and hitting one of those wooden balls way up in the air. Could have killed someone if it came down on their head. Your neighbors have any of those?

Luckily I have not had any issue with my own solar panels being damaged from impacts. I was warned that if the panels are on a single story home you can still get errant rocks thrown up by lawn mowing. If you have anyone who mows the grass with a power mower they can hit rocks and launch a projectile at very high speed. Anyone with a lot of grass that needs to be trimmed nearby? Not familiar with suburban life in your area but if that is common it could also be a cause.
« Last Edit: December 07, 2015, 07:10:48 pm by jnissen »
 

Offline LaurenceW

  • Frequent Contributor
  • **
  • Posts: 258
  • Country: gb
    • It's Time, Jim, but not as we know it
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #103 on: December 07, 2015, 07:56:16 pm »
-1 for baseball-size hail.  We had a MEGA hail storm four years back - it smashed car windows, dented car panels and wrote cars off, smashed greenhouses, shredded trees and damaged tiles on dozens of house roofs (we lost 20+ tiles), but the PV panels were untouched! Indeed, I'd go so far as to say that the panels [protected the section of the roof that they cover!  And you kinda KNOW when a hailstorm like that hits. I think a one off (natural) hail stone is a non-starter.

However, the event did cause me to consider the need to replace a panel at some point - and here's the rub. My top-of-the-line Sanyo (now Panasonic) panels are already no longer manufactured! :-[ This may be common in this fast-moving market. So any replacement will stick out like a saw thumb (if your array is visible). Moral; if you need a replacement panel, get one while you still can!

And bypass diodes or not, I tend to find that when one panel goes into shade, it really kills the output of the whole string. It's VERY noticeable, beyond the loss of output of one panel alone. Pretty sure that once the rain gets in, you'll lose the output of that one panel.
If you don't measure, you don't get.
 

Offline keethrax

  • Contributor
  • Posts: 31
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #104 on: December 07, 2015, 09:42:10 pm »
I think the batterizer guys flew over and chucked a AA on him.
 

Offline DrGeoff

  • Frequent Contributor
  • **
  • Posts: 709
  • Country: au
    • AXT Systems
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #105 on: December 07, 2015, 09:53:08 pm »
I think the batterizer guys flew over and chucked a AA on him.

Of course!
Inter-Continental Batterizer Missiles!

Was it really supposed to do that?
 

Offline Muttley Snickers

  • Supporter
  • ****
  • Posts: 1970
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #106 on: December 07, 2015, 10:09:06 pm »
I think the batterizer guys flew over and chucked a AA on him.

Of course!
Inter-Continental Batterizer Missiles!

Couldn't have been them, they have a reputation for missing targets..... :phew:
 

Online georges80

  • Frequent Contributor
  • **
  • Posts: 806
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #107 on: December 07, 2015, 11:41:40 pm »
Not the issue here...

There are arrays of panels in the bush in oz along the rail that runs to Kal and also is the line for the Indian Pacific. Lots of ore and other stuff travels on that line. There's a gravel access road between the solar array (that powers gear in the siding) but it's all round gravel.

Anyhow, we stop at the siding somethings since there's a rain water tank fed from the roof of the siding, tap to access the water so great to top up our own tanks. Looking at the solar array (which is tilted somewhat at the rail since the rail is to the north of the array) you can see quite a lot of rock shards (more like spear heads, NOT gravel) that have  impaled themselves in various panels of the array. There's a wire mesh 'shield' near the panel, so we assume that was installed after they found the damage on the panels. Presumably enough of the array continues to work that no need for replacement of the damaged panels has been necessary, yet...

We have assumed that those rocks are shot at very high speed when the train goes by, not sure if due to some of the rocks (falling out of the cars) ending up on the rail and then being spit out when a wheel tries to go over the rock. Pretty scary since I would not want to be standing (or in a vehicle) anywhere near that array (or similar distance) to the rail line.

The tempered glass doesn't shatter other than around where the rock penetrates. Some are partially visible on the rear side of the array. Some serious momentum at work...

cheers,
george.

 

Offline Macbeth

  • Super Contributor
  • ***
  • Posts: 2507
  • Country: gb
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #108 on: December 07, 2015, 11:47:20 pm »
Bogans for neighbours and drongos for their kids. It's that simple.  ;)
 

Offline continuo

  • Frequent Contributor
  • **
  • Posts: 303
  • Country: de
 

Offline Smokey

  • Super Contributor
  • ***
  • Posts: 1582
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #110 on: December 08, 2015, 01:17:33 am »
I got it... I figured it out!! 
It was.... Dave Jones long lost brother....

Casey Jones!!

https://youtu.be/7_6KMGB_Pkw?t=2m7s
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #111 on: December 08, 2015, 01:24:29 am »
I wasn't expecting THAT amount of deformation!

Is that a regular golf ball?  I would have expected the case to crack deforming that much.

That is not a normal hit on the ball. Look again at Youtube and there are a lot of golf hit slow motion video's. Nothing comes close to the compression initially shown.


I did check out other videos of normal golf ball impacts and it is very clear that the impact in the link given is extreme.  I just found it difficult to believe that, in the case of such an extreme impact, the casing did not fail.

The other thing is, that the surface this ball (in the video) hit was completely unyielding (in any practical sense).  Dave's glass panel was far less so.  The deformation and failure of the glass would have reduced the peak deceleration by orders of magnitude over the video example - and the shape of the ball would not have changed much.  Certainly less than is visible in the other golf ball videos I saw.

While the point of the reference to ball deformation (that it would result in damage indicating a diameter larger than the projectile at rest) is clearly sound, I doubt the forces involved would have produced much of a variance.  Certainly nowhere near enough for a golf ball to leave a cricket ball sized imprint, IMHO.
« Last Edit: December 08, 2015, 04:46:19 am by Brumby »
 

Offline TooOldForThis

  • Regular Contributor
  • *
  • Posts: 55
  • Country: us
  • H: 42.576MHz/Tesla
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #112 on: December 08, 2015, 02:50:37 am »
Can't this be 'fixed' by putting a sheet of polycarbonate over the broken glass and sealing the edges with aquarium cement?  The polycarbonate will absorb some of the energy, but it will keep the water out (assuming it's not already full of water).
 

Offline mtdoc

  • Super Contributor
  • ***
  • Posts: 3579
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #113 on: December 08, 2015, 03:44:06 am »
I got it... I figured it out!! 
It was.... Dave Jones long lost brother....

Casey Jones!!

https://youtu.be/7_6KMGB_Pkw?t=2m7s

Driving that train, high on....

 

Offline Tandy

  • Frequent Contributor
  • **
  • Posts: 372
  • Country: gb
  • Darren Grant from Tandy, UK.
    • Tandy
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #114 on: December 08, 2015, 01:44:33 pm »
You are all wrong, it must have been Segan throwing his lego to see if it would fly  :P
For more info on Tandy try these links Tandy History EEVBlog Thread & Official Tandy Website
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #115 on: December 09, 2015, 02:29:38 am »
Wow ... Such a good arm on a little tacker...!!
 

Offline crispy_tofu

  • Super Contributor
  • ***
  • Posts: 1124
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #116 on: December 10, 2015, 08:46:29 am »
That's one big Lego...  :popcorn:
 

Offline Kalvin

  • Super Contributor
  • ***
  • Posts: 1786
  • Country: fi
  • Embedded SW/HW.
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #117 on: December 10, 2015, 02:48:46 pm »
Stray bullet perhaps? or someone with a slingshot and BB/marble?

No way a marble had enough energy to shatter that.
We don't have a gun culture in Australia, and so hardly anyone has one. So the odds of that are borderline zero.

Then, its a beer can. Foster's.

Or the kids were playing with something round and hard, and oops. Those things happen from time to time.
« Last Edit: December 10, 2015, 02:51:09 pm by Kalvin »
 

Offline Gunhaver

  • Newbie
  • Posts: 1
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #118 on: December 12, 2015, 07:33:33 pm »
Hi All. I'm curious if anyone else did some back of the envelope calculations? I read through this thread and didn't see any guesses to the properties of the impact object. I decided to work the problem with two different sets of assumptions.

Firstly i assumed the object was a bullet-type and based my assumptions on data for a 7.62 NATO bullet (11g, terminal velocity of 90 m/s both from wikipedia). I also assumed the glass has a shattering pressure limit of 70MPa (pulled from a random technical presentation of nominal tempered glass). I also assumed an impact duration of 1ms before the object bounced away at the end of the impact event. I also assumed the tip of the bullet hits first and deforms until the diameter of the impact surface is 7.62 mm. Using all of these values, and the formula for net force during an impact (Fnet = delta momentum / delta time), I calculated that the pressure imparted by the impact object was around 17.37 MPa. The lower bound i found for shatter pressure of tempered glass was 7 Mpa, so this number is in the right ballpark i think. This tells me that my assumptions are close. I also assumed a relatively low-velocity impact from essentially a vector normal to the surface of the glass after reading this summary of glass shattering forensics on the FBI's website: https://www.fbi.gov/about-us/lab/forensic-science-communications/fsc/jan2005/index.htm/standards/2005standards7.htm

I thought about this all so more, and i decided to also work the problem with the assumption that the impact event imparted a pressure 70MPa, and then figure the mass of the object based on that. This made more sense to me because we know at least a minimum amount of pressure was imparted, so it is a safer assumption. In this case, i assumed a spheroid object, which gives a drag coefficiant of 0.47 through air. I also assumed 70% relative humidity, 70 deg F (21 C), and an altitude of 19 feet (about 6m) EGM96 MSL. I also assumed the object's radius to be 0.5 inches this time around (about 1.27 cm). I also assumed an impact duration of 0.7 ms this time because wolfram alpha informed me that the average impact duration of a baseball hitting a bat is 0.7 ms. I could be way off here on the duration.

I should point out, that i read this thread after i assumed the radius, and there is a post in this thread that explains how the radius of the object is likely greater than the white crushed area on the glass. Even so, i think my numbers are still the right magnitude. Given all of the above assumptions, i now calculated the impact object's mass to be around 387.018 grams (or about 13 ounces, or 0.85 lbs). 13 ounces sounds right to me (it agrees somewhat with my first calculation), and i think it really points to a meteorite type object.

I could take this even further and calculate a probable radius for the final resting place of the object. It seems we could use the concentric ring pattern to extrapolate the impact angle, and then we can simply figure the angle relative to the earth. Then it would be a matter of figuring a range for momentum transfers to the glass (there would be an upper bound less than 100% transfer because the object was not embedded and is not sitting right next to the panel). At any rate, this would give us a range of trajectories that should draw a line on the ground. Treat this line as a diameter of a circle, and then you have a grid for Dave to search for a meteorite type object. I think it would be very cool if we predicted where the object would be, and then Dave actually found it.

Feel free to tear my calculations apart and make them better (or just point out what is wrong). It is all back of the envelope, so i'm not pretending any of it is accurate beyond magnitude level analysis. Does anyone else have any values? I'm very curious.

This was a very entertaining way to spend my morning when i'm feeling sick. Thank you for reading this far!
 

Offline Macbeth

  • Super Contributor
  • ***
  • Posts: 2507
  • Country: gb
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #119 on: December 12, 2015, 08:44:08 pm »
Then, its a beer can. Foster's.
Nope. Beer cans are far to light when empty, and no self respecting bogan would chuck a full tinnie at the roof without consuming the fine malt liquor first. Far more likely the drongo chucked an empty stubbie of VB instead.  ;D
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29650
  • Country: au
    • EEVblog
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #120 on: December 12, 2015, 09:05:20 pm »
I have been contacted by LG Australia, and they said that not a single one of these panels has ever shattered in over 300,000 installed in this country. Not by hail or anything else.
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4295
  • Country: ca
  • Canadian po
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #121 on: December 12, 2015, 09:11:45 pm »
Aren't you lucky then!
 

Offline Ian.M

  • Super Contributor
  • ***
  • Posts: 7995
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #122 on: December 12, 2015, 09:39:20 pm »
Then, its a beer can. Foster's.
Nope. Beer cans are far to light when empty, and no self respecting bogan would chuck a full tinnie at the roof without consuming the fine malt liquor first. Far more likely the drongo chucked an empty stubbie of VB instead.  ;D

Blame the Murray Crays!

http://www.youtu.be/-6FSoKdPneo
« Last Edit: December 12, 2015, 09:47:10 pm by Ian.M »
 

Offline Macbeth

  • Super Contributor
  • ***
  • Posts: 2507
  • Country: gb
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #123 on: December 12, 2015, 09:57:10 pm »

Blame the Murray Crays!

Those critters are just protecting you from the Drop Bears and the deadly Cassowaries


 

Offline DrGeoff

  • Frequent Contributor
  • **
  • Posts: 709
  • Country: au
    • AXT Systems
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #124 on: December 12, 2015, 10:49:22 pm »
I have been contacted by LG Australia, and they said that not a single one of these panels has ever shattered in over 300,000 installed in this country. Not by hail or anything else.

And none of their washing machines ever caused a fire either ...
Was it really supposed to do that?
 

Offline Stray Electron

  • Frequent Contributor
  • **
  • Posts: 714
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #125 on: December 12, 2015, 10:55:01 pm »
I have been contacted by LG Australia, and they said that not a single one of these panels has ever shattered in over 300,000 installed in this country. Not by hail or anything else.


    E-bay it!
 

Offline WN1X

  • Supporter
  • ****
  • Posts: 73
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #126 on: December 12, 2015, 11:10:16 pm »
I have been contacted by LG Australia, and they said that not a single one of these panels has ever shattered in over 300,000 installed in this country. Not by hail or anything else.

I would think that would be enough for them to come out and see the damage first hand. And, perhaps, provide a free replacement panel  :-+
- Jim
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #127 on: December 13, 2015, 02:09:43 am »
I have been contacted by LG Australia, and they said that not a single one of these panels has ever shattered in over 300,000 installed in this country. Not by hail or anything else.

An impressive record.  I would think they would be rather interested to examine it to try and determine the how and why of it's failure.

There is one reservation - and that is whether they are being absolutely honest about the zero failure .  I say that not to make such an accusation, but to allow for the possibility that a marketing spin had been placed on the statement.  I will add that I believe such an action is rather unlikely since, in today's internet culture, there is almost nowhere to hide.


I am interested to hear what LG does next - and whether Dave is up for a warranty claim or an expense.
 

Offline NANDBlog

  • Super Contributor
  • ***
  • Posts: 4428
  • Country: nl
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #128 on: December 13, 2015, 06:55:10 pm »
I have been contacted by LG Australia, and they said that not a single one of these panels has ever shattered in over 300,000 installed in this country. Not by hail or anything else.
So there is 1 broken out of 300.000 and you said the glass is the most expensive part of the panels?
I smell over engineering. I would take a few percent discount for even a ten-hundred fold failure easily.
 

Offline LabSpokane

  • Super Contributor
  • ***
  • Posts: 1899
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #129 on: December 13, 2015, 08:23:41 pm »
I have been contacted by LG Australia, and they said that not a single one of these panels has ever shattered in over 300,000 installed in this country. Not by hail or anything else.

Dave,

 LG may not have seen a shattered panel, but it's a little hard to believe that this is the first time it's ever happened. 

And for those criticizing the cost of the glass, that's actually one of the key efficiency features of a panel: the glass needs to be thin in order to be as transmissive of light as possible.  Surely that has to come at a cost.  I wouldn't be surprised if there's a coating involved. 
 

Offline edpalmer42

  • Super Contributor
  • ***
  • Posts: 1619
  • Country: ca
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #130 on: December 13, 2015, 08:44:04 pm »
I have been contacted by LG Australia, and they said that not a single one of these panels has ever shattered in over 300,000 installed in this country. Not by hail or anything else.

Dave,

 LG may not have seen a shattered panel, but it's a little hard to believe that this is the first time it's ever happened. 

And for those criticizing the cost of the glass, that's actually one of the key efficiency features of a panel: the glass needs to be thin in order to be as transmissive of light as possible.  Surely that has to come at a cost.  I wouldn't be surprised if there's a coating involved.

How many times have you phoned tech support and heard "No one has ever reported that problem before"?

Yeah, right.  :-DD

Ed
 

Offline ruffy91

  • Regular Contributor
  • *
  • Posts: 237
  • Country: ch
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #131 on: December 13, 2015, 09:47:58 pm »
At my university there is a project with panels following the sun. There are 10 of them on a pole about 3m high. One night all of them shattered and the damage looked very similar.
It was kids wo threw stones at them (ca. 100g
-500g range).
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29650
  • Country: au
    • EEVblog
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #132 on: December 14, 2015, 12:53:00 am »
LG may not have seen a shattered panel, but it's a little hard to believe that this is the first time it's ever happened. 

That's all we have to go on.
They have not seen one, and no reports from any installers in Oz.

Quote
And for those criticizing the cost of the glass, that's actually one of the key efficiency features of a panel: the glass needs to be thin in order to be as transmissive of light as possible.  Surely that has to come at a cost.  I wouldn't be surprised if there's a coating involved.

Solar glass is also very low iron content which helps with the transmittance.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29650
  • Country: au
    • EEVblog
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #133 on: December 14, 2015, 12:54:43 am »
An impressive record.  I would think they would be rather interested to examine it to try and determine the how and why of it's failure.

They are sure it's a large vertical impact.

Quote
I am interested to hear what LG does next - and whether Dave is up for a warranty claim or an expense.

They want to give me a free replacement. I just have to get it installed.
 

Offline coppice

  • Super Contributor
  • ***
  • Posts: 4602
  • Country: gb
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #134 on: December 14, 2015, 01:17:05 am »
I have been contacted by LG Australia, and they said that not a single one of these panels has ever shattered in over 300,000 installed in this country. Not by hail or anything else.
The statement from LG is meaningless. The best they could reasonably claim is that they are unaware of a shattered panel. Impact damage like Dave's panel isn't going to be repaired under warranty, so the failure would never be reported to LG. I wonder how many single panels they have sold to previous domestic purchasers of array sized bundles of panels? That might say something about the number of failures due to damage.
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #135 on: December 14, 2015, 02:01:17 am »
I am interested to hear what LG does next - and whether Dave is up for a warranty claim or an expense.

They want to give me a free replacement. I just have to get it installed.

Good news.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29650
  • Country: au
    • EEVblog
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #136 on: December 14, 2015, 02:02:58 am »
The statement from LG is meaningless. The best they could reasonably claim is that they are unaware of a shattered panel.

Of course that is what they meant.
 

Online IanB

  • Super Contributor
  • ***
  • Posts: 9541
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #137 on: December 14, 2015, 02:04:54 am »
The statement from LG is meaningless. The best they could reasonably claim is that they are unaware of a shattered panel. Impact damage like Dave's panel isn't going to be repaired under warranty, so the failure would never be reported to LG.

I rather doubt that. Warranty or no, if I had a panel break I would be calling the manufacturer to report it.

Sure, with cheap items I would write off the loss as one of those things, but with expensive items I sure as heck would follow up on a failure.
I'm not an EE--what am I doing here?
 

Offline coppice

  • Super Contributor
  • ***
  • Posts: 4602
  • Country: gb
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #138 on: December 14, 2015, 02:29:54 am »
The statement from LG is meaningless. The best they could reasonably claim is that they are unaware of a shattered panel. Impact damage like Dave's panel isn't going to be repaired under warranty, so the failure would never be reported to LG.

I rather doubt that. Warranty or no, if I had a panel break I would be calling the manufacturer to report it.

Sure, with cheap items I would write off the loss as one of those things, but with expensive items I sure as heck would follow up on a failure.
If I had a panel damaged by the weather I would be claiming under warranty on the basis of the panel's fitness for purpose. Are you really saying you would complain about accidental high impact damage? Would you complain to Michelin if someone slashes your car tyres? Some things are outside the manufacturer's control, and most people are reasonable enough to accept that.
« Last Edit: December 14, 2015, 02:43:25 am by coppice »
 

Offline Paul Moir

  • Frequent Contributor
  • **
  • Posts: 865
  • Country: ca
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #139 on: December 14, 2015, 02:43:12 am »
Some things are outside the manufacturer's control, and most people are reasonable enough to accept that.
Sure, but if you say have a surplus in your warranty contingency fund, perhaps you would want to spend it on some good will?  Can be good for both the manufacturer and the unfortunate.  :)

 

Offline coppice

  • Super Contributor
  • ***
  • Posts: 4602
  • Country: gb
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #140 on: December 14, 2015, 02:45:00 am »
Some things are outside the manufacturer's control, and most people are reasonable enough to accept that.
Sure, but if you say have a surplus in your warranty contingency fund, perhaps you would want to spend it on some good will?  Can be good for both the manufacturer and the unfortunate.  :)
Well, if Dave's free replacement panel gets significant publicity maybe we'll find just how many people have had a panel broken. :)
 

Online blueskull

  • Supporter
  • ****
  • Posts: 12272
  • Country: cn
  • Power Electronics Guy
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #141 on: December 14, 2015, 02:46:12 am »
One of the reasons to buy from a top brand with big money is to get A++ service. Somehow like an insurance service.

Just like Apple care, they cover any damage, including water damage and falling damage.
 

Offline coppice

  • Super Contributor
  • ***
  • Posts: 4602
  • Country: gb
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #142 on: December 14, 2015, 02:52:26 am »
One of the reasons to buy from a top brand with big money is to get A++ service. Somehow like an insurance service.

Just like Apple care, they cover any damage, including water damage and falling damage.
Some products are sold with an explicit inclusion of accidental damage cover. Most are sold with anything beyond "fair wear and tear" explicitly excluded. Top brands may look at accidental damage, and cover cases where the product failed too easily, but don't expect too much from them.

Apple is a poor example to choose. For a long time they refused warranty claims for any phone with the humidity stickers triggered. That included pretty much every phone sold in a humid climate.
« Last Edit: December 14, 2015, 03:42:12 am by coppice »
 

Online blueskull

  • Supporter
  • ****
  • Posts: 12272
  • Country: cn
  • Power Electronics Guy
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #143 on: December 14, 2015, 03:01:37 am »
Apple is a poor example to choose. For a long time they refused warranty claims for any phone with the humidity stickers triggered. That included pretty much every phone sold in a humid climate.

That's how they sell Apple care >:D.
I had a 15''rMBP, it shows watermark on its screen, and I swear I never impacted the screen.
Apple service refused to fix it, even in warranty, because they claimed it is cause by external impact.
The fact is, many LCD screens will develop these watermarks by fungus and humidity in light spreading sheets on its own.
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 15087
  • Country: za
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #144 on: December 14, 2015, 04:27:13 am »
Samsung here has a 2 free repairs under warranty policy on the larger units sold from around mid last year. Covers a single screen replacement or a single glass replacement, irrespective of the cause. They do however show on the invoice the amount you would otherwise have had to pay for this, along with the reminder that the next one is not free. Seeing as they are the largest seller in the smartphone market this is a good selling point.
 

Offline station240

  • Supporter
  • ****
  • Posts: 851
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #145 on: December 14, 2015, 05:00:20 am »
LG may not have seen a shattered panel, but it's a little hard to believe that this is the first time it's ever happened. 

That's all we have to go on.
They have not seen one, and no reports from any installers in Oz.

I'm sure installers have broken them during transport/installation.
Possible it is the first reported to them as damaged after install.
 

Offline coppice

  • Super Contributor
  • ***
  • Posts: 4602
  • Country: gb
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #146 on: December 14, 2015, 05:12:39 am »
Solar glass is also very low iron content which helps with the transmittance.
Low iron glass as an option for domestic glazing makes a big difference to the price of windows. With solar panels having become very price sensitive, I wonder how many actually use this type of glass?
 

Offline Someone

  • Super Contributor
  • ***
  • Posts: 2102
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #147 on: December 14, 2015, 07:47:44 am »
Solar glass is also very low iron content which helps with the transmittance.
Low iron glass as an option for domestic glazing makes a big difference to the price of windows. With solar panels having become very price sensitive, I wonder how many actually use this type of glass?
In volume most glasses are cheap, multilayer wideband antireflective coatings for the glass would be the expensive part (while being cheap to put on the silicon its self). There are even cheaper plastic films you can use instead of glass but they have comparatively poor impact protection. Losses in the protective layers/coatings are a very small part of the efficiency of the assembled panel so there is lots of wiggle room to use less than ideal parts.
 

Offline Someone

  • Super Contributor
  • ***
  • Posts: 2102
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #148 on: December 14, 2015, 07:57:07 am »
Here is a good example of the challenges of AR coatings:
http://info.adimec.com/blogposts/bid/40330/Anti-reflection-coatings-improve-accuracy-for-high-performance-cameras
So with a good quality AR coating you could push an extra 4-6% light through to the cells (which will heat up more etc so wont see the whole gain) so that 4% on an 18% assembly only brings you up to 18.8%. Small gains but the wider literature says prices are coming down enough that its becoming routine for solar panel assemblies, but while they dont mention the typical improvements or efficacy of the coating its just another meaningless marketing point which may or may not actually improve performance of the panel.
 

Offline Rasz

  • Super Contributor
  • ***
  • Posts: 2273
  • Country: 00
    • My random blog.
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #149 on: December 14, 2015, 08:34:08 pm »
The statement from LG is meaningless. The best they could reasonably claim is that they are unaware of a shattered panel. Impact damage like Dave's panel isn't going to be repaired under warranty, so the failure would never be reported to LG.

I rather doubt that. Warranty or no, if I had a panel break I would be calling the manufacturer to report it.

Sure, with cheap items I would write off the loss as one of those things, but with expensive items I sure as heck would follow up on a failure.
If I had a panel damaged by the weather I would be claiming under warranty on the basis of the panel's fitness for purpose. Are you really saying you would complain about accidental high impact damage? Would you complain to Michelin if someone slashes your car tyres? Some things are outside the manufacturer's control, and most people are reasonable enough to accept that.

of course he would, this is why insurance companies invented new type of insurance just for the US market, the 'I dont give a f' type where you can claim it if you 'accidentally' threw your phone into the wall during heated argument, or dropped it in the toilet.

One of the reasons to buy from a top brand with big money is to get A++ service. Somehow like an insurance service.
Just like Apple care, they cover any damage, including water damage and falling damage.

mm the Apple myth is strong with this one
https://support.apple.com/en-us/HT204104
no, you need a special moron insurance for that
Who logs in to gdm? Not I, said the duck.
My fireplace is on fire, but in all the wrong places.
 

Offline thm_w

  • Super Contributor
  • ***
  • Posts: 1356
  • Country: ca
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #150 on: December 15, 2015, 12:27:24 am »
In volume most glasses are cheap, multilayer wideband antireflective coatings for the glass would be the expensive part (while being cheap to put on the silicon its self). There are even cheaper plastic films you can use instead of glass but they have comparatively poor impact protection. Losses in the protective layers/coatings are a very small part of the efficiency of the assembled panel so there is lots of wiggle room to use less than ideal parts.

We used a plastic/epoxy coated panel for a while at work and it was horrific. The coating is soft so scratched easily, and dirt would stick or embed itself in the surface.
I'm sure there are better parts out there, but I can't think of where you'd ever want to use the cheap panels we got.
 

Offline rs20

  • Super Contributor
  • ***
  • Posts: 2150
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #151 on: December 15, 2015, 02:05:54 am »
They use Physical Vapor Deposition (PVD) using a hard vacuum to put the silly decorative metallic finish on plastic kitchen blenders; it becomes economic with large quantities. And very nice antireflective coatings are commonplace in camera lenses.

With that in mind, I'd be very surprised if the glass used in solar panels wasn't coated (at least on the underside) -- it seems like a very easy efficiency win for a very low recurring cost?  I know the glass panels are larger than camera lens elements, but still.

Also, regarding antireflective coatings being delicate: yeah, making a coating that is both durable, not overly sticky, and antireflective is a difficult compromise. But don't forget that the underside of the glass is a potential reflection point. Even if they only coated the underside of the glass, that still halves your reflection losses, and the side of the glass that sees the outside environment is dead-standard uncoated glass (or differently coated).
 

Online blueskull

  • Supporter
  • ****
  • Posts: 12272
  • Country: cn
  • Power Electronics Guy
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #152 on: December 15, 2015, 05:14:11 am »
PV panels are very cost sensitive. From the perspective of a utility company, to make this cost effective (forget about the California rubbish renewable energy regulations, we only talk money), at large scale, only the cheapest and most robust ones can be used. Efficiency does not matter, unless it is too low.

Utility companies run on very low margin with very high initial capital, and are regulated heavily by regulatory bodies.

I did a case study on Alabama Power, it reveals if we do not use existing infrastructure, and build a new grid in Alabama, we have to sell energy for >10cents per kWh to make acceptable profit to get invested.
 

Offline LabSpokane

  • Super Contributor
  • ***
  • Posts: 1899
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #153 on: December 15, 2015, 06:30:49 am »
PV panels are very cost sensitive. From the perspective of a utility company, to make this cost effective (forget about the California rubbish renewable energy regulations, we only talk money), at large scale, only the cheapest and most robust ones can be used. Efficiency does not matter, unless it is too low.

Utility companies run on very low margin with very high initial capital, and are regulated heavily by regulatory bodies.

I did a case study on Alabama Power, it reveals if we do not use existing infrastructure, and build a new grid in Alabama, we have to sell energy for >10cents per kWh to make acceptable profit to get invested.

You need to keep in mind that Dave is not a utility trying to repurpose a brownfield site. Dave bought the LG panels due to their quality and efficiency.  Trying to optimize the output from a fixed size rooftop is a slightly different value proposition than utility-scale solar. Dave knowingly paid a premium and got great service when he had a problem.
 

Online blueskull

  • Supporter
  • ****
  • Posts: 12272
  • Country: cn
  • Power Electronics Guy
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #154 on: December 15, 2015, 06:39:36 am »
You need to keep in mind that Dave is not a utility trying to repurpose a brownfield site. Dave bought the LG panels due to their quality and efficiency.  Trying to optimize the output from a fixed size rooftop is a slightly different value proposition than utility-scale solar. Dave knowingly paid a premium and got great service when he had a problem.

I think most of the premium goes into minor improves and better material as well better service.

For the process (PVD, CVD, whatever), I don't think it makes economical sense for LG to build a new premium product line for small amount of premium customers.
 

Offline Chris Jones

  • Regular Contributor
  • *
  • Posts: 76
  • Country: au
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #155 on: December 16, 2015, 01:45:46 pm »
They use Physical Vapor Deposition (PVD) using a hard vacuum to put the silly decorative metallic finish on plastic kitchen blenders; it becomes economic with large quantities. And very nice antireflective coatings are commonplace in camera lenses.

With that in mind, I'd be very surprised if the glass used in solar panels wasn't coated (at least on the underside) -- it seems like a very easy efficiency win for a very low recurring cost?  I know the glass panels are larger than camera lens elements, but still.

Also, regarding antireflective coatings being delicate: yeah, making a coating that is both durable, not overly sticky, and antireflective is a difficult compromise. But don't forget that the underside of the glass is a potential reflection point. Even if they only coated the underside of the glass, that still halves your reflection losses, and the side of the glass that sees the outside environment is dead-standard uncoated glass (or differently coated).

The encapsulant ("glue") between the glass and the cells is usually EVA or sometimes silicone, but in any case it has a similar refractive index to glass so there is not much reflection from the interface between the glass and the encapsulant and not much point in applying anti-reflective coatings on the underside of the glass.
 

Offline Ian.M

  • Super Contributor
  • ***
  • Posts: 7995
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #156 on: December 16, 2015, 03:55:56 pm »
What can be done with a shattered solar panel?  Once the new panel is up and working, maybe a teardown?   Can the shattered glass be effectively re-bonded by resins like the one in the video near the start of the topic? Can the glass be removed and the panel hacked up and re-glazed to power small low voltage projects?
 

Online blueskull

  • Supporter
  • ****
  • Posts: 12272
  • Country: cn
  • Power Electronics Guy
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #157 on: December 22, 2015, 09:15:41 am »
What can be done with a shattered solar panel?  Once the new panel is up and working, maybe a teardown?   Can the shattered glass be effectively re-bonded by resins like the one in the video near the start of the topic? Can the glass be removed and the panel hacked up and re-glazed to power small low voltage projects?

 

Offline gildasd

  • Frequent Contributor
  • **
  • Posts: 926
  • Country: be
  • Engineering watch officer - Apprentice Officer
    • Sci-fi Meanderings
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #158 on: December 22, 2015, 04:09:48 pm »
What can be done with a shattered solar panel?  Once the new panel is up and working, maybe a teardown?   Can the shattered glass be effectively re-bonded by resins like the one in the video near the start of the topic? Can the glass be removed and the panel hacked up and re-glazed to power small low voltage projects?


UV Resistant epoxy, no filler, slow reactant, very thin layer.
I'm electronically illiterate
 

Offline Seekonk

  • Super Contributor
  • ***
  • Posts: 1830
  • Country: us
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #159 on: December 22, 2015, 04:49:05 pm »
Free panels!  I can see people sticking on those shattered glass decals and taking a picture.
 

Offline Kleinstein

  • Super Contributor
  • ***
  • Posts: 6206
  • Country: de
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #160 on: December 22, 2015, 05:40:57 pm »
A simple AR coating (just 1 or 2 layers) is not expensive. You can get this on windows at a rather low extra costs. Coating window panes is standard (at least in Europe) - in small quatities you may have to pay extra for an uncoated gals.

Even if its only some 3 % of more energy gained, the cost of the coating is likely less than 3% of the panel, and higher efficiency panels also need less area and mounting.

Sould not be a golf ball, as the panels should withstand hail of comparable size and weight und thus therminal speed.  This one looks like not just shatterd but way over the design limit.
 

Offline gildasd

  • Frequent Contributor
  • **
  • Posts: 926
  • Country: be
  • Engineering watch officer - Apprentice Officer
    • Sci-fi Meanderings
Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #161 on: December 22, 2015, 06:50:38 pm »
I found proof of what happened...
I'm electronically illiterate
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf