Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
I have noticed on the forum mention of cheap panels, but I have looked on eBay and gum tree and I haven't seen any cheap panels other than those which are posted and take about two weeks if you are lucky. I would like to pick up a 120 watt panel in Sydney south west if possible. Jaycar have one at $250 but I think that is poor value. Does any member know where I can get one in my area? Also a reply to one of my previous posts said that second hand 250watt panels could be had for $50. I can't find any at this price so any enlightenment would be appreciated.
" previous posts said that second hand 250watt panels could be had for $50. I can't find any at this price so any enlightenment would be appreciated."
it could depend on where people are, here in Adelaide about $75 seems the go on gumtree
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 10:06am 27 Dec 2017
Copy link to clipboard
Print this post
The cheaper ones don't last long, I have seen 250W panels for $50 each but you have to buy 20. I bought 20 for $700 once but have not seen them at that price. To get one panel for $50 is a tall order.
You will buy for less on Gumtree if your patient and prepared to act immediately they become available. Jaycar is usually one of the more expensive places, especially for mounting hardware.
There are only 10 types of people in the world: those who understand binary, and those who don't.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 12:35pm 27 Dec 2017
Copy link to clipboard
Print this post
I was factory trolling yesterday and spotted a solar place. Went round the back and there was a shattered 300W panel. Looked in their big Dumpster and there was an opened but full box of the mounting fixings and half a box of rail splices.
Tested the panel today and it seems to be fine. Was overcast all day so didn't expect to get a good reading but it was good enough. Threw it up on the shed roof and connected it to the side by side radiator fan shroud and wired them in series. Spun them up real well. I have it sitting in the shed window for ventilation which it does well. Put my shattered 250 panel which also works fine back on the light in my old freezer I use for seedling raising. In a few brief times the sun broke the clouds, I could hear the fans really starting to howl so must have been getting plenty of juice.
Happy with that score. I'll check there every weekend now. Might have a look on the net if there are any other solar places around I can check out for old or boken panels, inverters or paraphernalia.
I last bought 20x 250W panels for $40 each back in Sept. Have seen the same guy who had a full trailer load of these things ( wondered how he towed it with the sh*tbox van he has as it must have weighed 2 ton) advertising 190w panels on and off but no more 250's. I'll contact him in the new year and see if I can get another 20 250's off him.
I see panels in Qld that seem to be cheaper than in Syd. The guy I got mine from said he had a supplier in Qld and sent most of them back to the middle east. Lot of stolen cars and boats go back there too I'm told by a high up detective mate.
Not sure why you can't get cheap panels in Syd, I see them quite often but I pass because I'm not interested in 6 or 8, I want another 20 and I don't want to end up with a Hodge podge of different ones. That said, been thinking of getting a set of 8 or so if I can get them at the right price and look at them for boosting the hot water system.
Why do you only want a 120W panels?
Looking on Gumtree right now there is a guy selling 190W panels for $45. Another one, 200W panels, $50 ea Guy I messaged the other day on another site has 8x 220W panels he will do for $200. Think I'll go get them for mucking around with. Could go with the 190's I have as well.
Really not sure why you can't find them. Always seems to be something on offer and sure would beat Jaycar prices as would any solar supplier you went to.
Certainly there are plenty of morons out there asking stupid amounts though. I responded to an ad for laughs the other day for 8 panels for $1000. Offered $200. Idiot came back calling me names. I asked what size and brand the panels were. Didn't know. I gave it to him back well and truly about calling me names when he had no idea of what he even had and pulled a stupid figure out of his nether regions as if what he thought his self serving price was the actual value of the things without even bothering to see what the going rate was. Hasn't changed his ad though. Might have a hissy fit like I see on fleabay all the time, " Last time I'm advertising these ( at my inflated reserve price) and if it does not sell it's going to the tip". You are trying to scare people into paying too much for your crap?? Talk about full of one own self importance!
My other favorite is " Need it gone Now"...... Predictably priced to kill as well.
Plenty of clowns out there like this selling panels. Many of them will tell you they paid $10-12K for them 7-10 years ago as if they are still worth anything like that. I have linked back a solar distributors price list with much larger, warranted and more efficient panels which could be $100ea cheaper and still get some idiotic indignant reply that they are worth what they are asking. Probably are in fantasy land but in the real world.....
I always wonder what happens with these people? How long does it take for them to wake up and make their price realistic ( not just on panels but all manner of things they over inflate) or do they think they are right and never sell the stuff?
The ones with panels that really tick me off at the ones that say they just upgraded so they know what a new system is worth but try to fund 80% of that with the sale of the old panels!
There is one add for second hand solar panels on gum tree Sydney region at the moment. It is amongst a myriad of caravans and boats etc. $90 for 190watts and a fair way from my home. The reason I want a 120 watt panel is that I have built a silicon chip charge controller and It won't take a larger panel. I may go to larger panels in the future but my present need is for an 120 watt. There are some on eBay for about $119 but I am not sure of the quality and the delivery time is too long.
dwyer Guru Joined: 19/09/2005 Location: AustraliaPosts: 574
Posted: 11:54pm 27 Dec 2017
Copy link to clipboard
Print this post
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 12:09am 28 Dec 2017
Copy link to clipboard
Print this post
Are you sure it won't take a larger panels as in it will burn out be destroyed or it will just not handle any more than 120W and disregard the rest?
Gumtree are HUGELY Car and caravan Biased. Mate and I were playing a game with it the other night. See what search term you can put in that does NOT bring up a vehicle with a 100Km radius. You'd be amazed what you can punch in there and still get a car, van truck or other vehicle ad come up in the search results. It's owned by ebay and I think they keep it undeveloped and Gumby to drive people to using ebay where there are no free ads/
Again, I don't know what you are searching for but right now there are at least 6 ads for panels that are reasonable atm in greater Sydney, 3 that are outside Sydney and another 4 in Sydney that I consider are dreamers.
If you specifically have to have a 120W panel ( I'd check it) then things might be more difficult. Even so, thee were some low wattage panels I saw on Gumtree although they weren't $50.
If you HAD to limit yourself to 120W, all you would need to do would be add in a resistor.... like a 100W 24V headlight globe in series with the output from a larger panel and that's all you would get.
If you can't use anything larger than a 120W Panel I'd be seriously thinking about getting a new controller and a decent size panel you could use in the future. Maybe you could buy another controller and run that off a larger panel with your controller so they share the output and only get what they can handle.
I'd tend to think the output is limited but the input could be anything.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 12:16am 28 Dec 2017
Copy link to clipboard
Print this post
Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814
Posted: 12:30am 28 Dec 2017
Copy link to clipboard
Print this post
There are a lot of people going from 1kw and 3kw systems to 5kw systems atm, because of the rebate going down in jan, and when they install them they pull the old panels down and take them away (imho they `should' be given back to the householder as they ARE theirs unless its a condition of the purchase of the new panels contract- which the ones Ive seen, it isnt)
So yes (IMHO) they are actually `stolen'
And I expect the supply of these older panels will dry up as the upgrades stop (until Labor get back in and reintroduce the solar schemes again)
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 02:31am 28 Dec 2017
Copy link to clipboard
Print this post
Given that I have bought several lots of panels from people that have had them replaced and there are loads more on gumtree and ebay selling them privately, I'm not sure that they are " taken" as you put it.
First lot of panels I got was from a lady not far away complaining they wanted a lot extra to take the old panels. Maybe that was after the twats disconnected them all with pliers instead of just pulling apart the MC 3 Connectors.... or they didn't know how.
Got an inverter off a guy a couple of months back, same thing. had the whole system there, racks, panels etc. wasn't interested in the small panels so got the inverter which must have been replaced because it was a 5Kw on a 1.5 system.
Maybe some installers take the panels to onsell as part of their deal or maybe it's just people want them taken away which I can well see as well. Not everyone could be bothered advertising stuff or want to deal with people ringing or messaging and coming to their homes.
Your point about the used panels drying up may be valid. As far as I can see though, in NSW at least the scheme does not simply end, the rebates are being reduced over 15 years. I'll guarantee a good price hike in power prices will see another flurry of installs and upgrades. Just the same, I'm already looking for another 5KW of panels to put up to hedge my bets.
Who was it that introduced the last solar Scheme where the FITS were .60C and who Kyboshed it? Was it one in the same or one introduced it and one killed it?
I don't follow Politics. They are ALL as bad as each other. It's not a matter of picking who will do the best job, it's a matter who will fk things up less than the other.
I'm not the sharpest tool in the shed but I'm not that freaking stupid to be bothered with any of that self serving politics crap. A more corrupt and bigger scam ( maybe other than globull warming and the green charade ) has never been allowed to exist... although I think technically the environmental thing is political too is it not?
Atm it seems everything is green washed but at the same time they are going out their way to discourage something useful and beneficial like people putting solar on their roofs. Obvious reason for that is it costs them and their big business power company buddies lost revenue dollars and that's the cardinal sin.
As long as their is a buck to be made from the green thing it will be OK. Minute it costs them money, it will be illegal or at very least discouraged.
The solar MPPT charger and lighting controller kit has been mainly designed by silicon chip magazine for a remote lighting application and has a controlled output as well as other features. It has a switching mosfet which can handle 10 amps so a larger panel would exceed this and probably burn out the mosfet. In any case the 120 watt panel is the maximum specified by the magazine. I mainly built it as I can follow exactly what is happening with the mpp tracking and the three stage charging that is being applied to the battery.I am using an expensive geltec gel battery which requires specific charging parameters and with controllers bought off the shelf, these are unknown quantities and could shorten the life of the gel battery. These batteries do not like being overcharged and also require temperature compensation for the maximum and float charging. This silicon chip unit is powered by a pic microprocessor and has various adjustments as to maximum charge voltage and temperature compensation. Even so some of the parameters did not suit my battery exactly so I was able to download the software and modify it. (which was difficult as it was in assembler language.) I purchased a spare pic and programmed it with my specific values in MPLAB with a pickit3. I replaced the standard pic and have been checking it using a 20 watt panel but I really need a 120 watt panel to get the final values. I also have a data logger shield on an Arduino which can log the voltages as the controller goes through its charging cycle. So that is why I want a 120 watt panel. Incidentally if you type is second hand solar panels in the Sydney region of gumtree I went through every page and there was only one add.
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 04:23am 28 Dec 2017
Copy link to clipboard
Print this post
Solar panels are here to stay and power bills are going to keep going up. So people will be upgrading, another source is demolitions, as homes are being knocked down to build units and stuff there are homes with panels on them being knocked down.There are only 10 types of people in the world: those who understand binary, and those who don't.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 10:56am 28 Dec 2017
Copy link to clipboard
Print this post
Amps is dependent on Voltage. 250W panel is usually 7-8 amps. There are still 4 ads on the first 2 pages but if you are just looking for 120W panels then that may be different.
oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686
Posted: 11:29am 28 Dec 2017
Copy link to clipboard
Print this post
Solar panel amps are a function of the surface area of the cell, and the incident light.
The voltage of a cell is dependent on the depletion zone chemistry. For silicon diodes it is about .6v. Solar cells are just diodes.
So the voltage is dependent on the depletion zone differential which is effected by temp. ( chemical reactions are temp dependent ), and the internal resistance of the cell(s) circuits, and the cells themselves.
So a panels power is the result of the number of cells and the size of the cells.
5x5inch cells are in the 4-6 amps range, and 6x6 inch cells in the 7-9 amp range. The voltage can be taken as about .5v/cell
Lower power ( 190watts etc) are generally 5x5 with 72 cells/panel, and 6x6 are generally 60 cells per panel. ( 230 - 270 watts etc.)
60 cell panels are more desirable for off grid applications, as a mppt is not really required, and in most cases not useful at all for most of the mppt devices, unless you couple the panels to a high voltage and then bring it down with the buck in the mppt.
This is only useful if you have long cable runs, other wise better to buy more panels with the money saved from no mppt.
I won't buy 5x5 72 cell panels for these reasons.
If you buy an Australian GSL 60 amp mppt, you will find that 60 cell panels cannot usefully be used according to their tables for a 48v system.. so $400 down the drain.... been there done that.
.........oztulesEdited by oztules 2017-12-29Village idiot...or... just another hack out of his depth
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 04:20am 29 Dec 2017
Copy link to clipboard
Print this post
Why can't you just buy a cheap 190 and cover part of the panel up? Detune it.Cheers Caveman Mark Off grid eastern Melb
I could do that but the battery is actually from my caravan and compact size of a panel is important. I would want to use it my caravan again. The 190 watt panel is a bulky thing at 1510 by 810. I noticed Kogan have some cheaper panels claimed to be German quality but sold out at the moment.
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 08:06am 29 Dec 2017
Copy link to clipboard
Print this post
Well if you want it for a caravan maybe look at the lightweight flexible 100W panels. Ever picked one up side by side to a glass/alum panel? Dunno about you, but I have gone very close to total weight with a surprisingly small amount of crap. Keeping weight down in vans is a real priority for a lot of people. Just a thought.Cheers Caveman Mark Off grid eastern Melb
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 09:05am 29 Dec 2017
Copy link to clipboard
Print this post
This might work with solar hot water panels but its generally not a good idea to partially shade a voltaic solar panel. Its output will most likely drop drastically from the disruption of the cell voltages. Where do you get this idea from?Klaus
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 09:54am 29 Dec 2017
Copy link to clipboard
Print this post
Where do I get the idea from? Bush mechanics, maybe not a good idea, but neither is running a underpowered controller that can't handle 1 decent panel.Cheers Caveman Mark Off grid eastern Melb
oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686
Posted: 10:18am 29 Dec 2017
Copy link to clipboard
Print this post
if you partially cover a panel, the internal resistance will go through the roof... thats why you don't cover any cells.... weakest link in the chain comes to mind.
........oztulesVillage idiot...or... just another hack out of his depth
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
Print this post
