Author Topic: Home Rooftop Solar Power System Update - Shattered Panel!  (Read 40482 times)

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Offline Halcyon

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #25 on: December 06, 2015, 07:15:41 pm »
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.
 

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #26 on: December 06, 2015, 07:26:37 pm »
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

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #27 on: December 06, 2015, 07:50:19 pm »
Doesn't your home insurance cover weather damage?
 

Offline PinheadBE

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #28 on: December 06, 2015, 08:10:05 pm »
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, 08:24:56 pm by PinheadBE »
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Offline Psi

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #29 on: December 06, 2015, 08:14:26 pm »
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, 08:23:10 pm by Psi »
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Offline jitter

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #30 on: December 06, 2015, 08:22:09 pm »
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, 08:42:22 pm by jitter »
 

Offline crispy_tofu

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #31 on: December 06, 2015, 08:54:34 pm »
Doesn't your home insurance cover weather damage?
But was it caused by the weather?
 

Offline Artlav

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #32 on: December 06, 2015, 09:02:11 pm »
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.
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Offline G7PSK

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #33 on: December 06, 2015, 09:08:46 pm »
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

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #34 on: December 06, 2015, 09:13:55 pm »
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

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #35 on: December 06, 2015, 09:35:54 pm »
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

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #36 on: December 06, 2015, 10:21:29 pm »
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

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #37 on: December 06, 2015, 11:03:14 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

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #38 on: December 06, 2015, 11:15:49 pm »
As it's toughened glass, I wonder if it could have been a latent manufacturing defect that popped due to normal thermal cycling. 
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Offline ornea

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #39 on: December 06, 2015, 11:19:40 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

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #40 on: December 06, 2015, 11:25:32 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

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #41 on: December 06, 2015, 11:27:32 pm »
If Dave's place is under a flightpath, https://en.wikipedia.org/wiki/Blue_ice_(precipitation)
 

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #42 on: December 06, 2015, 11:30:20 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

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #43 on: December 06, 2015, 11:33:08 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.
 

Online Rasz

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #44 on: December 06, 2015, 11:55:32 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.
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Offline zoltan

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #45 on: December 06, 2015, 11:56:06 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

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #46 on: December 06, 2015, 11:57:13 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

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #47 on: December 07, 2015, 12:11:39 am »
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.

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Online Rasz

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #48 on: December 07, 2015, 12:51:23 am »
I don't believe something the size of a golf ball would create the damage shown.

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Offline Brumby

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Re: Home Rooftop Solar Power System Update - Shattered Panel!
« Reply #49 on: December 07, 2015, 01:48:44 am »
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.
 


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