Demolished solar panels - Page 1
Forum section: electronics / general

author: TerraHertz
author_rank: Super Contributor
timestamp: September 06, 2016, 03:41:41 pm
content: I suppose with so many houses having solar panels these days, this scene will become more common.How often do you suppose a building demolition company would bother to remove solar panels from a roof before wrecking? I suspect not very often, if ever. Certainly not in this case.Here's something seen a few days ago. Thought I'd take some pics. Amazingly, one of the two panels dropped with the roof (and still visible in the rubble) turned out to be intact. No damage other than one slightly dinged frame corner. In late afternoon sunlight it develops 41V oc, 4A sc, which is pretty close to spec.Old houses, partly demolished, are very atmospheric. Could have posted more pics but not on topic.Edit: It turns out the front glass sheet in solar panels is tempered safety glass, and shatters into tiny pieces. The backing sheet is fiberglass, and the front glass, cells, and backing sheet are all held together by a clear rubbery glue. So there's no chance of recovering intact cells from broken panels.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: September 06, 2016, 03:58:09 pm
content: What a waste

author: nfmax
author_rank: Super Contributor
timestamp: September 06, 2016, 04:04:25 pm
content: Also dangerous - the panels won't stop generating just because the house is being demolished. I assume the contractors will have isolated the mains supply before starting, but they ought to have removed & made safe the panels as well!

author: Cyberdragon
author_rank: Super Contributor
timestamp: September 06, 2016, 05:05:36 pm
content: There's toxic chemicals in those!EPA ALERT!

author: TAMHAN
author_rank: Frequent Contributor
timestamp: September 06, 2016, 05:25:36 pm
content: I am now going on a VERY wild WAG, my memory is fading but for Terra, with whom I agree on so many things, I will risk it.I can remember, at least 10 years ago, that a friend of mine who worked in arms physics once said that dropping a solar cell, in practice, does no harm - you simply end up with "many smaller ones". I would drop one to try...but I dont have one on hand.

author: XOIIO
author_rank: Super Contributor
timestamp: September 06, 2016, 06:49:43 pm
content: Uhg, idiots.

author: Kleinstein
author_rank: Super Contributor
timestamp: September 06, 2016, 07:11:36 pm
content: It is not only the solar cells that look strange. At least the shown silicon solar cell usually are not a chemical hazard. It's just a waste of material (e.g. aluminum structure and frames) and a mess to sort things afterwards. Also old modules might still have a value if still working - not much, but still cheaper than to pay for waste disposal.At least in Germany demolition has changed quite a lot from that. They really start to separate parts before bringing down the main structure. So they may remove the windows, doors, remove electric cables, water tubing, floor material and for sure also solar cells. Its just easier to sort things when still intact than from a big mess.Of cause things get different if this is house badly damaged by an earth-quake. But lucky Germany has very few of those

author: JPortici
author_rank: Super Contributor
timestamp: September 06, 2016, 07:12:20 pm
content: No risk here for this to happen (or at least, here in the north)if the demolition people did something like that they would certainly be hanged by their privates. we are still dealing with the eternit fallout..

author: apelly
author_rank: Unknown
timestamp: September 06, 2016, 08:18:43 pm
content: I did some work for a large demo. company many moons ago. The deal was that the demo. co. got to salvage everything on the site. The salvage value was factored into the bid price. These guys are not in the demo. business. I suspect fly-by-night property developers.edit:Wankers!

author: nfmax
author_rank: Super Contributor
timestamp: September 06, 2016, 08:34:23 pm
content: Perhaps it was just a really wild party?

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: September 06, 2016, 08:48:14 pm
content: Quote from: apelly on September 06, 2016, 08:18:43 pmFor really large demolitions such as schools, hospitals, most professional companies will quote based on estimated scrap value. Obviously risky but it's a cut-throat business.This does look like it's been trashed by a bunch of kids as real demo guys would have known the scrap value of everything.It's the sort of demolition done by druggies as they took what was easily available, such as the cable and flung the panels off.

author: station240
author_rank: Unknown
timestamp: September 06, 2016, 11:28:36 pm
content: I'd suspect the owner is one of those Chinese investors, they aren't allowed to demolish existing housing without approval, but they do anyway.See:https://firb.gov.au/resources/guidance/gn06/They haven't even bothered to clean out boxes of stuff inside the house, much less remove the solar from the roof.

author: XOIIO
author_rank: Super Contributor
timestamp: September 06, 2016, 11:57:54 pm
content: Quote from: Kleinstein on September 06, 2016, 07:11:36 pmJapan does it even better.

author: TerraHertz
author_rank: Super Contributor
timestamp: September 07, 2016, 12:25:19 am
content: Quote from: station240 on September 06, 2016, 11:28:36 pmThis is quite possible. There were various clues the place had been rapidly trashed, by non-professional people with little interest in scrap value. Then they stopped work and left the wreck as it is for a while. Some things not removed for resale that should have been, like stainless steel kitchen sink. And yes, items from the interior like DVD player and boxes of stuff are in the wreckage. Also the interior shows it's been open to rain for some time, so the 'demolition' has frozen for some reason.I don't drive past there often, but probably will be henceforth. Mum's declining health, and that's the way I get to the hospital for her area. I'll be keeping an eye on this site, from curiosity.Interestingly the panel I rescued has a few cells with the same kind of lightning EMP surface tracking as in these other panels I was given:http://everist.org/NobLog/20160504_solar_panels_vs_emp.htmQuote from: XOIIO on September 06, 2016, 11:57:54 pmNeat!From the video: "You can't use explosives to demolish buildings where there are other buildings nearby."Ha ha, Larry would beg to differ. Just apply triple insurance, set up a believable scenario, factor in an exceptional bullion windfall and some share shorting, and it's all good.

author: Red Squirrel
author_rank: Super Contributor
timestamp: September 07, 2016, 01:55:30 am
content: It's sad the waste that happens in general in demolition. Lot of stuff that is still good often goes with the building, sometimes due to laziness, other times due to stupid bureaucracy. Ex: anything involved in an insurance write off has to be destroyed. Such BS.

author: hendorog
author_rank: Super Contributor
timestamp: September 07, 2016, 02:59:41 am
content: Possibly demolished urgently due to potential for imminent collapse?I can see the garage looks a bit munted in the brickwork department.

author: TerraHertz
author_rank: Super Contributor
timestamp: September 07, 2016, 06:07:22 am
content: Quote from: hendorog on September 07, 2016, 02:59:41 amNo, definitely not. It's solid brickwork, and they've basically just removed the roof and all interior woodwork. I didn't see any sign of termited timber in the rubble pile.A very old house though, ripe for replacing with a duplex or block of units. (In some developer's mind.)The suburb is one with a very high Chinese presence.

author: hendorog
author_rank: Super Contributor
timestamp: September 07, 2016, 06:44:50 am
content: Quote from: TerraHertz on September 07, 2016, 06:07:22 amDamn, thats just terrible.As an aside, the term 'solid brickwork' is an oxymoron to people who live in Christchurch after what happened in the earthquake

author: Red Squirrel
author_rank: Super Contributor
timestamp: September 07, 2016, 07:55:03 am
content: Another thing to consider is solar cells are actually physically dangerous, they are very sharp when broken. Not really something you want in your lawn if you like to spend any time bare foot or have kids.

author: Artlav
author_rank: Frequent Contributor
timestamp: September 07, 2016, 08:23:43 am
content: Are you sure it was actually being demolished?Looks more like some mobsters with a bulldozer had an "accident".

author: TerraHertz
author_rank: Super Contributor
timestamp: September 07, 2016, 12:19:31 pm
content: Quote from: Artlav on September 07, 2016, 08:23:43 amSure.

author: Brutte
author_rank: Frequent Contributor
timestamp: September 07, 2016, 04:35:22 pm
content: Quote from: TerraHertz on September 06, 2016, 03:41:41 pmThe "rubbery glue" is most likelyethylene vinyl acetate. Squeeze a bit and smell - EVA has a distinguishable odor (smells a bit like silicone sealant). You can dissolve that easily incyclohexanebut it is a dirty job.What I would suggest is to heat panel up (120 degC won't damage the cells) and when it softens you can try picking up broken glass first. I think a careful heat gun and patience would do but that depends on how badly smashed the panel is.I do not think you might be able to salvage any cells as these are all soldered together at the back + there is also EVA at the back + the Si itself is 0.1mm thickBut you should be able to replace or bridge the cells that are damaged.