Don’t Buy Second Hand Solar For Your Home

second hand solar shop

You’ll Pay A High Price For Second Hand Solar Equipment

“Psssssst!  Wanna buy some slightly used solar panels?  They fell off the back of a truck.  Or possibly off the back of a roof.  Maybe they even fell off the back of a roof of a truck.  We just don’t know.  But what I do know is they are tier one panels in great condition – they didn’t fall far – and they’re cheap, so if you are looking to install rooftop solar you’d be a fool not to buy them, right?”

Wrong.

The only way it would make sense to use second hand solar panels is if you were paid to.  Because the “solar rebate1” which lowers the cost of rooftop solar by providing Small-scale Technology Certificates (STCs) only applies to new panels using second hand ones will actually add thousands of dollars to the cost of rooftop solar.

“Well what about this solar inverter?  It’s only two years old and fell off the back of eBay.  It still has 2 years of its 5 year warranty left!  It’s half the cost it was new, so trust me, you don’t want to miss this deal!”

Brand new inverters are about half the cost they were 3 years ago, so I’m pretty sure I do want to miss that deal.  Especially since that inverter almost certainly doesn’t meet the current Australian Standard (AS4777.2) and so will be illegal to install.

The Moral Of Today’s Story is…

In case you haven’t guessed, the theme of today’s post is how buying second hand solar hardware is a bad idea.  While used solar panels may be great for some potentially lethal hobby projects or making coffee tables2 for normal rooftop solar installations used panels and inverters are generally worse than useless.

Solar Panels Have To Be Clean Energy Council Approved

To be installed in Australia solar panels have to meet standards set by the Clean Energy Council3 (CEC).  While there is a good chance random second hand panels you buy will meet current standards it is still possible they won’t.  Especially if they were ones first installed before July 2013 and don’t meet modern fire standards.

Do You Want STCs?  Because New Panels Is How You Get STCs

Do you like money?  If you do, then you are going to want to save money by buying new panels and not second hand ones.  I know this may sound a little strange as second hand is normally cheaper, but when it comes to rooftop solar second hand will increase the cost of an installation by thousands of dollars.  This is because the STCs that lower the cost of rooftop solar can only be received by solar panels once and any second hand ones you buy will almost certainly have had all their STCs already wrung out of them.

In a recent article I mentioned how STCs will lower the cost of installing a new 6.5 kilowatt rooftop solar system by around $4,590 for a typical Australian household, which is roughly around one-third the typical cost for a system of that size.  For a 5 kilowatt system STCs will reduce the cost by around $3,530 and for a small 3 kilowatt system the reduction will be around $2,120.

This may not seem like much to an American now that Trump is making everyone rich, but for the average Australian this is a lot of money and not to be sneezed at.  (Personally, I wouldn’t even cough at it.)  So don’t believe Cashmerchant69 when he tells you his slightly used solar panels are still good for STCs even if he does have a 94% Positive Feedback rating on eBay.

STCs Are Enough To Pay For A Brand New Set Of Panels

Because solar panels have fallen so far in price STCs can cover the entire cost of competitively priced tier one panels.  There can even be money left over and you get the advantage of brand new panels with a brand new warranty.  For second hand panels to beat that someone would have to pay you to install them.

Second Hand Panels May Be Damaged

Another problem with used panels is they may not be in top condition.  The more panels are moved around the more likely they are to get banged about and develop micro cracks that can cause their performance to deteriorate.  Who knows just how gently the panels were treated when they were uninstalled and transported from their original site?

It is possible to test panels to see how well they perform, but it might do just dandy while its cracked pieces of solar cell are nicely pressed together, but after a couple of years on the roof experiencing a daily thermal expansion and contraction cycle, problems may arise.

Just to be clear, I’m not saying that moving panels will automatically cause them to contract solar cell rot and deteriorate and fail, but I am saying it’s not good for them and on average new panels will be more reliable.

Few Second Hand Inverters Can Be Legally Installed

The Clean Energy Council also has a list of approved solar inverters that must be used in order to receive STCs4.  In addition, your local Distributed Network Service Provider (DNSP)5 reserves the right to screw you over, I mean, limit the equipment that can be connected to the grid, but generally if an inverter is on the CEC list it is good to go.

The trouble is, because of changes made to the standards, unless it is very new, a second hand inverter is unlikely to be on the approved list and will be illegal to install.  So getting a second hand inverter is likely to be an expensive mistake.

Even if you do your homework and make sure the second hand inverter is one that can be used, installers may not be thrilled by the idea of using a random second hand inverter they may never have used before.  So you may have trouble finding someone willing to install it and if you do find someone they may charge extra for the hassle of figuring out how the darn thing works.

When Is It A Good Idea To Use Second Hand Solar Gear?

So just when is it a good idea to buy second hand solar hardware?  Well, almost never.  There are exceptions.  For some applications requiring low voltage DC power a used solar panel may be just the thing.  But for most people it would be no use to them at all.

There are enthusiasts who like to get their hands on second hand solar gear and fool around off-grid where Network Operators can’t fine them potentially hundreds of thousands of dollars for connecting illegal equipment to the grid.  But unless those people have the qualifications and experience required to safely work with that kind of equipment, I can’t condone that sort of activity.

Sure, I can’t stop anyone from doing it, but I’m not allowed to say it’s okay.

My ex-wives have beaten it into to me that I can ‘t even give the impression that doing something potentially dangerous is acceptable.

In fact, the judge said I’m no longer even allowed to hypothetically discuss how a lawn mower engine could be used to make a small aircraft with my children anymore.  I don’t know what the big fuss was.  They healed.

But still, I did make a promise.

Footnotes

  1. The solar rebate technically isn’t a rebate, but plenty of people call it that, so we’re kind of stuck with the term.
  2. I think the best use of some solar panels is coffee tables.  Just be sure to get an accredited solar installer to wipe them down with some Mister Shine every three months so they stay in warranty.
  3. If it helps, you can think of the Clean Energy Council as being sort of like the Jedi Council in Star Wars or if you are really imaginative, you can pretend they are like an industry body in the real world.
  4. The amount of STCs received depends on the total solar panel capacity, but the panels must have an approved inverter and the work must be overseen by an accredited installer in order to get STCs.
  5. DNSPs would be Imperial Forces if we are still going with Star Wars comparisons.
About Ronald Brakels

Many years ago now, Ronald Brakels was born in Toowoomba. He first rose to international prominence when his township took up a collection to send him to Japan, which was the furthest they could manage with the money they raised. He became passionately interested in environmental matters upon his return to Australia when the local Mayor met him at the airport and explained it was far too dangerous for him to return to Toowoomba on account of climate change and mutant attack goats. Ronald then moved to a property in the Adelaide Hills where he now lives with his horse, Tonto 23.

Comments

  1. Interesting considerations, thanks. However, if I’d get say, for example 10x190W 5 year old panels for $300 the lot, get a new inverter and end up with a close to 2kW system for around a thousand bucks that will likely run for at least the next ten years, would it really be a bad idea? How much would a brand new 2 kW system cost?

    • Ronald Brakels says

      1.9 kilowatts of new panels will provide, in most of Australia, around $1,340 worth of STCs at the moment. At the current low cost of solar panels that’s enough to potentially pay for that amount of brand new tier one solar panels. So you could be $300 ahead and have brand new panels with a brand new warranty that you can be very sure haven’t been mistreated.

      I’m afraid you are too optimistic about the cost of the rest of the hardware. Even a small 1.5 kilowatt inverter can be well over over $1,000 and then there is the racking, cabling, bolts, conduits, isolators, fuses, etc. And if it’s on-grid it will need to be installed by someone who is CEC accredited.

      Because 1.5 kilowatt inverters aren’t that much cheaper than 3 kilowatt ones and a smaller system doesn’t save much in labour, I’m afraid it’s not going to be that much cheaper than a 3 kilowatt system which can cost $4,000 to $6,000 for one with high quality components that is professionally installed.

      • Yes Minister says

        My 10kw on-grid system cost me $33,000 out of pocket in mid 2011 but paid for itself within 4 years. Since then I’ve added a homebuilt 3kw off-grid system mit chinese batteries inverter and used panels for a total cost of $5,000 and that is well on the way to paying for itself after three years use..The argument that moving panels constitutes a death penalty is fallacious. Does the author suggest that original panels are manufactured on the same site where they are installed ? As far as I’m aware, 99.9999999999% of items manufactured in the 21st century come from somewhere in China which entails a lot of transport..

        • Yes Minister says

          By the way, I’d install another dozen or so used panels tomorrow if I could find a space to put them. My roof isn’t exactly tiny, but 76 panels does use a fair bit of real estate. Those who feel compelled to pay a pimply-faced juvenile to do elementary installations might well be best using all new gear, but not everyone is so challenged that they can’t screw a few Mecanno components together. Sure electricity bites if you do the wrong thing, but then one doesn’t need a PhD in electrical engineering to hook up a few wires. What sort of university degree does the pimple-faced juvenile have ?

        • Ronald Brakels says

          I’m happy to check out the article you are referring to, but you’ll need to provide a link to it because it’s not this one.

      • Thanks Ronald, I haven’t looked into the current prices for a while, as I am stuck with my 1st generation 1KW system for another 5 years. I can’t expand without losing my lucrative feed in tariff.
        If the STC is taken out of the equation things change quite a lot, your figures look realistic.
        I was thinking though, what if I get an old set of panels, a cheap Chinese pure sine wave 2 kW off-grid inverter and 2 old car batteries as a buffer I’d be able to run my pool 100% on solar, which would safe me at least $400 a year. I haven’t done any further research yet. Your article just made me think about what I could do with used panels I saw on Gumtree? I wouldn’t need a 2 kW system just to run a pool, but it would cover better for the not so sunny days and the startup current of the pump. Your verdict? Cheers 🙂

        • Ronald Brakels says

          Well, if you are spending 2 kilowatt-hours a day running the pool filter and you pay say 25 cents a kilowatt-hour for grid electricity then you could cut your electricity bill by around $180 a year. I don’t know if that would be worth setting up a low cost system that might not be very durable.

          Using DC current directly is something that has been suggested. On possibility is heating water. The trouble with this is hot water use is likely to be highest when solar generation in the lowest. It has also been suggested DC current could be used for home heating. Provided a home has a reasonable amount of thermal mass it could provide the bulk of heating over winter and be supplemented during especially cold and cloudy periods.

          But DC current is of course a much greater fire risk than AC and I am not recommending anyone undertake these kinds of projects themselves unless they know what they are doing. This is all just hypothetical. But there are firms working on exactly these kinds of “guerrilla solar” methods to get around restrictions on how much grid connected PV people can install. But I haven’t seen anything that impresses me yet. At the moment general energy efficiency looks like it a better deal or possibly traditional thermal solar hot water.

          • I can see, you haven’t got a pool. The pump and the chlorinator together easily draw around 1kW, and that’s a small 1 hp pump. With the recommended 8 hours running time a day it would save some $700/year actually. But I manage to reduce the running time, especially in winter. Solar for a pool looks like a good investment to me. The chlorinator alone would be actually ideal for solar as it uses DC. I’ll have to do the figures on that. Isn’t it silly to produce DC from solar, convert it to AC and than back to DC? Efficiency around 50% or so 🙂

          • Ronald Brakels says

            Well, modern solar inverters may average around 96% efficiency going from AC to DC, but yeah, DC using appliances can be pretty terrible. My apple phone charger is supposed to be 74% efficient, which is one percentage point worse than my Nokia at 75%. Since my Nokia only needs to be charged every two weeks instead of almost constantly, I’d say it’s well ahead on efficiency. When no care is given to efficiency it can be much worse, like 40% for a moderately shoddy switched-mode power supply.

        • Yes Minister says

          Sizeable water pumps (I have one to provide pressure because I don’t have ‘town’ water) use a horrifying amount of power when starting. My 3kw chinese inverter invariably chirps whenever I turn on a tap although nothing else bothers it. In the near future I’ll build a soft start device to lessen the start current. I do have a 100l pressure tank but I think the bladder has passed its use-by date and a new tank is needed. Most days, even a bit overcast, I have more than sufficient power from 12 s/h 180w panels to run everything and the batteries are up to 57v by mid morning. That means the powers that be contribute 52c per kwh at up to 85kwh per day from the 64 grid-connect panels. No doubt the armchair experts will jump up and down claiming you beaut brand name inverters are a zillion percent more efficient, but at several thousand bucks as opposed to a few hundred for a chinese one, I fail to perceive any semblance of cost-effectiveness. In all probability the whiz-bang units are probably made in a chinese factory anyway. I do have Australian GSL charge controiller and a few tricky bits from GSL, but only because I couldn’t find another regulator capable of handling the 110 – 120v panel voltage. All GSL components have proven to be value for money anyway. That said, I see some new-fangled chinese off-grid inverters cum solar regulators for $700 – $1000 and I’d be inclined to give them a try if / when I have need of another off-grid inverter. SMA are probably the bees knees (I have two 50090TLs on the grid-connect system) but have you checked the price of Sunny Island !!!!!!!

          Those who aren’t capable of distinguishing between negative and positive have little choice but to employ a qualified installer, but anyone with a bit of knowledge can easily install and configure a smallish off-grid system without needing a mortgage. Used panels are a dime a dozen (actually I detest americanisms but that was the best concept that came to mind), chinese crap isn’t necessarily totally crappy, and GSL stuff is not only locally made but repairable and well priced. Good quality chinese AGM batteries complete the setup although I’m aware of a few installations with old truck batteries. Mind you I do believe deep cycle batteries are a good thing as my experience has been that they stand up to solar use much better. On the other hand, old mate who attended his own wake (he lived a few more days) ran two well-used truck batteries for 40 odd years and always had (12v) lights and tv. I chose to stick with all 240v appliances because they are cheaper and more available than 12v ones. In any case I have a reasonable complement of 21st century toys, all of which use a few electrons.and 12v wouldn’t cut it.

        • Yes Minister says

          Personally I wouldn’t install a 2kw off-grid inverter for anything except a few lights. Electric motors, even the squitty-sized ones in refrigerators and freezers draw five or six times their normal consumption on startup and brownouts aren’t generally nice to them. I have a 3kw off-grid chinese inverter and next one will be a 5kw even though my average power consumption is around 4.5kwn per day. Batteries are a similar situation, one can never have too much. Currently I have 4 x 12v x 280ah and whilst I can get by with them, I’m looking at a 24 x 2v x 1200ah setup from China for about $7000. Lithium batteries might be the flavour of the month but I can’t see value for money. The existing batteries are at 57volts by mid morning so I’m reasonably confident that bigger batteries would charge fully most of the time and if all else fails there is off-peak mains and the Honda generator even though its below wakens the dead.

          • Thanks for the info. You are far ahead on me on the subject. I was not aware that the startup current would be this high, and I have not seriously looked into it yet. My solar pool supply idea is still young 🙂

            Since I have grid power anyway, why not just install a relay that starts up the pump on grid power and then switches over to the inverter output. No startup power needed. Just a thought.

      • Yes Minister says

        Even a small 1.5 kilowatt inverter can be well over over $1,000

        Hmmmm, there are plenty of 3kw chinese ones on Ebay in the high $300s – low $400s. Even some reputable companies in Australia (hint one on the Sunshine Coast) sells chinese ones with a meaningful local warranty for around $600. Mine has lasted three years to date with no hint of trouble. Even if it carked it today, that works out at a fraction of the cost of a Victron or Outback and those probably come from a chinese factory like everything else.

  2. Yes Minister says

    There are two extremes to the political spectrum. At one end there is the conformist ‘she’ll be right mate’ tribe and at the other end there are those of us who subscribe to Eureka style pathological contempt for authority. In between there are shades of grey (or should that be green ??) It bothers me that some who portray a moderate approach are actually rusted-on conformists. In reality, off-grid solar is far from rocket science and even those who view transgressions of legislation as something akin to kiddie porn or high treason, can without too much difficulty install a workable system within existing legislation. Where is the inventiveness that is supposed to be a feature of Australian society when we are exhorted to play the multinationals game by their rules ? A bloke of my ex-acquaintance who unfortunately is no longer on this planet installed the crappiest off-grid solar system I’ve ever seen and ran his home on it for around 40 years until he attended his own wake (yes seriously). Every single component was junk but it provided sufficient power to raise a tribe of rugrats / yard-apes and keep his beer cold, and he wasn’t exactly a teetotaller while he was above ground.

  3. When we upgraded to a larger system the old panels were given away to someone who wanted them for camping? and the great little inverter was recycled at the tip.

    • Yes Minister says

      Old mate of the wake event got all his stuff from the dump, but it ran his off-grid home for 40 years. Mind you it wasn’t quite the Ritz. Lights and TV were 12v, the fridge was kerosene and he needed to start the generator when his missus wanted to use the washing machine. He did have a laptop but I think that was 12v. He couldn’t have connected mains power without spending several time what his property was worth but that didn’t stop them producing a bunch of apparently healthy sprogs (one of them did all the tiling in my home when it was built a few years back). Anyone who suggests off-grid solar is rocket science is barking up the wrong tree. Maybe if its an umpty-zillion megawatt system there is a case for professional installers but anything under 5kw should be well within the capabilities of anyone who has done a trade. I’m not for a moment suggesting non-professionals should mess with grid-connect systems, they are a horse of a completely different colour. Among other issues, giovernment muppets with too much authority and too little common sense tend to get their knickers in a knot when anyone challenges the profitability of their big business mates. Reminds me of a conversation I had with a turkey who claimed to be boss of the ‘Renewable Energy’ unit. I had this proposal for a community owned solar farm but this clown wouldn’t have a bar of it claiming it would adversely affect the profitability of Energex. Hmmmmm

      • I like the way you are wording it. Many big wigs are busy maintaining the wealth of interest groups.
        On the other hand, if you only just accidentally drop a spanner across the terminals of a car battery you can get hurt, start a fire or even lose your eye sight. So much for 12 V DC being harmless. And there are many other ways where one can stuff up and set the house on fire. But that’s where common sense comes in. I wonder if there is a statistic on how many house fires are started every year by shoddy work of professionals or simply bad quality equipment. Faulty cable insulation made in China comes to mind, not so long ago actually. On the news you just hear the phrase ‘the fire was not suspicious. Likely caused by an electrical fault’. I’d love to get more detailed information.

        • Yes Minister says

          Any clown who drops a spanner across battery terminals should avoid doing anything. The mind doth boggle what would happen with a 48v battery setup, or the 120v or more from the string. My grid-connect system gives over 500v per string but that is a bit too lethal for my taste. A big problem with common sense is that it is far from common.

  4. Was funnelled here by a Taswegian solar installer who works out of a shed in NW Tasmania pretending to be a big time opertaor.

    You have posted some common sense but a lot of jobs for the boys propoganda.

    You cannot get an SMA5000Tl for half of what it was a few years ago…in FACT the dollar isn’t exchanged at 1.10 US anymore so inverters actually went UP in price.

    So your comments are misleading.

    Also…you might get your panelasALMOST free when buying new ones…BUT…the overpriced aluminium rack mounting is OBSCENELY priced…and the guys installing it reckon they are worth a thousand bucks a day to screw together a bunch of 5mm allen screws.

    Simple fact is you can string together a bunch of panels…plug them into and inverter…wire a three pin plug to the inverter and plug the male into any power point in the house.

    It’s just another 240v appliance and a wholeindustry from a bunch of hippy dope smokers in NIMBIN Australia has made an empire for themselves.

    What a waste of money for all Australians.

  5. Yes Minister says

    As you’ve noted, and as I suggested several times, a smallish off-grid installation does not require a doctorate in rocket science, but then I know plenty of Australian males who would be hard pressed to fill up their car with the correct fuel. Putting those tricky MC4 connectors on correctly might be a stretch too far for some. .I wouldn’t do any wiring for another mug but I have no hesitation doing stuff for myself. Mind you I have a bunch of trade and professional qualifications albeit none in PV systems.

  6. There is Good quality second hand and there is poor quality New, ask me I purchased a new 1Kw system back in 2009 $8000 the Chinese panels all now have micro cracks in the cells, The CMS2000 inverter died before the warranty was up, but the company was already gone, The AC output cable from the inverter was not fitted to the breaker properly the wire was not clamped in the breaker all done by CEC Accredited installer, And I am sure I am not on my own.
    I use second hand Japanese panels charging my 48 volt system they work great. Horses for Courses

  7. Yes Minister says

    Exactly. I’ve experienced less issues with my personally installed off-grid system with used panels and chinese inverter than I have with my big name professional installed on-grid system.

  8. I’m a bit confused.

    I have a grid-connected premium tariff 1.5km solar system in Victoria.

    I have just pulled from the roof of my brother’s house in Melbourne a 1.7kw system with a Xantrex GT2.8-AU 2800 Watt Grid Tie Solar Inverter which worked perfectly until it was carefully disassembled by an A-grade sparky mate of mine over the weekend.

    Obviously I don’t want to lose my PFIT, but I also don’t want to waste my brother’s perfectly good system (which BTW has an inverter that’s large enough for the two)…

    Any suggestions?

  9. Dave Campbell says

    Hi Ron,
    Just a quickie from a newbie.

    What value would be given to new 185watt Trina or Conergy Power Plus panels which are not fire rated.

    These are new old stock. Considering their limited capacity for use, also where best could they be utilised ?

  10. Sandy Marwick says

    What about uninstalling and then reinstalling your own system. Planning a knockdown rebuild and the existing 12 panels and powerwall battery are still only 18 months old. We’re planning on taking them off the roof before the knockdown and then reinstalling them on the new house. Is this a viable option?
    I’m assuming the battery is worth the work given the price of them, but are we better off going for new panels and a new inverter?

    • Ronald Brakels says

      Because the costs of removing and reinstalling a system are so high, I would get quotes for that and for a new system. After taking into account the value of new warranties to you, you can then decide which is the best option.

      I think you are definitely right that keeping the battery would be worthwhile.

  11. Yes Minister says

    In the case of off-grid systems, the criticism is nonsensical.. Anyone capable of installing an off-grid system can do the job with used panels at much less than half what a new system would cost. My off-grid system cost me $5,000 and has worked fine for four years, whereas a professional would have charged $15,000 or more..The gotcha is ‘capable’, its not rocket science but anyone who goes ‘huh’ when asked if they understand Ohms law doesn’t fit my ‘capable’ criteria. On-grid systems are a completely different issue. I will do limited 240v work, but only if I can isolate the circuit. My on-grid system produces 600vDC and I wouldn’t even dream of messing with that.

  12. Stand alone system , great idea but the most expensive part is the batteries and carefully maintaining else you would kill the batteries before you know it , kind off been there don’t that 🙂 .my (3kw inveter) 48v to 240v is working great in the last 4 years as long as you don’t over discharged the batteries .

  13. What a load of codswallup. Did the author write this on behalf of a utility or what? The only thing missing from this scare campaign is that your insurance would be voided if your house burns down. As the comment on the 40 year off-grid like said, where is the invention here. I’ve got a 13kw non-compliant on-grid system chugging away earning me enough to pay my water and council rates. Go figure. It’s time these utilities were brought to their knees and the perverse outcomes and unintended consequences of poorly consider subsidies were ended. Meanwhile people should take advantage and get out and do something as long as they are capable.

  14. I get my 250w monocrystalline panels for 30 bucks now.
    I got 12…yes 12..SMA5000Tl inverters for 40 bucks each.

    everything works in my off grid setup…in the suburbs.

    who cares about CEC accredited fan boys from doped up Nimbin?

    i don’t grid feed…I would rather let the electrons fall on the ground than give them away to a utility to onsell for 3 times what they pay me.

    Oh…the STC’s…great…the wholesale price of a 300w panels is now $AUD110 and the nice accredited installers sell for $25o…yep….that will swallow up the “rebate” nicely…add some overpriced aluminium racking and bingo…all compliant.

    FFS an inverter only needs a male plug and plug into a power point…

    This article is a blatant attempt at jobs for the boys protection.

    I am throwing up on my keyboard.

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