Ebay solar panels; don’t buy any until you read this
Ever wondered why your eBay Solar Panel doesn’t produce anywhere near what it should do? Maybe you’ve been scammed like a heap of other people, by false advertising sellers on eBay.
I’m in the market for another 12V solar panel, for the top of our Dmax’s Canopy. I’ve bought a couple over the years, and each time I’m in awe of how much cheaper they’ve become.
However, what I’ve discovered just recently, is a lot of 12 volt solar panels being sold on eBay are falsely advertised. If you want the best eBay solar panels, start with ones that are correctly advertised.
Check the solar panel dimensions
This false advertising purely relates to panel sizes, and claiming that a panel is rated to a higher wattage than what it actually is.
I’ll give you an example:
The panel I’m chasing is 200W, and I know that a 200W panel should be 1580mm long, by 808mm wide. Now, I jump on eBay, and I flick through the results, and open a few different options up.
If you check the dimensions, some of the panels being sold as 200W are only 1430 x 680mm. On the surface, that might seem ok, but dig a bit deeper.
I compare the details, and they are exactly the same, except for the sizes. 18V max power voltage, 11.1A max power current, cell efficiency of 17%, mono panels and standard test conditions.
How is it possible for a panel at 1.27m2 to put out the same wattage as one at 0.9724m2? It’s not, and these eBay sellers are breaking the law by false advertising, and selling you a product that isn’t what you think it is.
It gets even worse – there are flexible ‘200W’ panels on eBay at 1070mm x 810mm (0.86m2). That’s a 47% size difference, with virtually identical specs.
Now, I understand there may be *some* variance in cell efficiency, and where the panels start compared to their borders, but not 47%. These eBay sellers are being totally unethical, and people are buying them!
EDIT – this is getting even worse. I saw a panel last night advertised as 300W, and its 1010mm by 670mm. That’s barely a 100W panel, being advertised as 3 times its capacity!
What to look for
12V mono solar panels with a cell efficiency of around 17- 20% should be roughly 0.0064m2 per watt. If there is a substantial variance from that, you are being misled. With that in mind, here’s roughly the sizes you should be looking at:
80W panel = 0.51m2
100W panel = 0.64m2
120W panel = 0.77m2
150W panel = 0.96m2
160W panel = 1.02m2
200W panel = 1.28m2
250W panel = 1.59m2
If you want to know that the panel you are looking at is actually the wattage advertised, do the maths above, or jump on a reputable sellers website (like Redarc, Projecta, Bosch or Australian Direct) and compare sizes.
The panels on our camper trailer came from Low Energy Developments, and we’ve been very happy with them so far.
You can read more about the new panels, batteries and the overall electrical upgrade here – Camper Trailer Electrical Upgrade.
If you are keen on looking at photos of the boat loader solar setup, you’ll find them here; Camper Trailer Boat Rack.
PWM controllers being sold as MPPT
Unfortunately, the false advertising doesn’t stop there. The next most common false advertising for 12V solar panels relates to the type of regulator used, and advertised. These are normally known as PWM and MPPT.
The latter is generally considered the premium style, and the manufacturing costs dictate there should be a price difference. If you are getting a panel with an ‘MPPT’ regulator for an amazing price, chances are its probably a PWM in disguise.
Buyer beware:
People have been buying solar panels off eBay for many, many years now. Many of the cheap ones are not going to be comparable in quality to the high end units, but they have proven themselves to be reasonable and great value for money.
However, its buyer beware; do your due diligence before handing your cash over to some scumbag on the other side of the world who thinks its OK to mislead their customers. Don’t believe the ebay solar panels review that says they are fantastic; check the dimensions and specs first!
Fixed or portable panels?
Before you buy 12V solar panels, have a think about whether fixed or portable ones are better. I’ve written a great guide that you can check out – Fixed vs Portable 12V Solar Panels; what’s better?
Solar blankets
Lastly, there are some pretty sweet solar blankets on the market today. Some are incredibly expensive, but they are portable, very light weight and easy to store. If you are considering getting one, have a read of this – Solar panels vs Solar Blankets.
We’ve also done a Kings Solar Blanket Review, after getting one as a backup for a trip up north.
Have you been ripped off?
I personally know a huge number of people who’ve bought panels that were advertised as being a much higher wattage, and it makes my blood boil. Have you been ripped off too? Let us know below in the comments!
Hey Steven,
It’s such a hit and miss world, and as you’ve experienced, sometimes buying quality gear is the only way to go. Imagine if you’d been running them into nice, expensive batteries and they’d been destroyed?
Cheers for your thoughts
Aaron
Found this after getting some dodgy “MPPT” controllers second hand off facebook.
Fortunately, the seller only charged me $10 and bluntly told me they weren’t great units – but they were fine for me to use with cheap panels as a beginner.
I wanted to learn from cheap units second hand, after seeing obvious scams where they’d list the controllers max power output as the solar panels output (12v x 20A = 240W, with a panel that would be lucky to be 10W)
This usually has them just adding one or two extra zeros to the units actual rating, i love seeing “MPPT” controllers where the image plainly shows PWM written on them.
One’s clearly PWM only when opened up and has crazy voltage spikes – so the “output” that’s meant to be from the battery will leap between say 12.5v and 15V every few seconds and the unit clicks
The other is a Kings branded unit that seemed like a genuine MPPT, but as soon as the batteries were fully charged just slammed them with 16V and started them boiling. Lucky i was with them at the time, or they’d have burned for sure.
The cheap nasty PWM unit pop-riveted to the panels themselves, when detached and kept closer to the batteries ironically has been the best so far, but barely getting 50W of the advertised 160W.
Hi Brock,
I’m happy with the renogy panels, but make sure the voltage suits.
Check this out: https://www.4wdingaustralia.com/camping/renogy-solar-panel-review/
All the best
Aaron
Hi Aaron and Sarah,
I’m from Lakes Entrance in Victoria and just bought a boat to live on. I’m trying to sort the solar setup at the moment.
A friend has offered me 2 solar panels 190W each and 1580 x 808 im size. Not sure what brand but he’s an electrician and has the same panels on his boat. The problem is for these to fit on my boat I’ll have to make some modifications to the boat which will remove some of its character and history.
I’ve found plenty of cheaper ones that would fit perfectly but a lot are the dodgy type. The Renogy 200W panels are absolutely perfect in size and I was about to order off them but read a heap of bad reviews about Renogy. I do know that people usually only give a review if it’s bad tho…
I see you bought two of these and say they put out the right amount of power! Can you confirm this is a brand you’d trust? I also have a Renogy battery monitor which seems fine.
Cheers guys!
This is awesome to find your blog just in time!
Hi Martin,
You’re welcome. Our contact us page has contact details
Cheers
Aaron
very helpful like additional info. do you have contact means
Martin
Hey Neil,
That is very helpful, and I’m not surprised nothing on eBay comes close. It seems like they are pushing the advertising friendship more and more each day too
Cheers, and all the best
Aaron
An even more simple calc is based on a fairly well accepted notion of 1000W / sq metre x Efficienct%. So a 250W panel that is purported to be 35% efficient would have to have 1 sqM of PV CELLs, which is not the dimensions of the panel, byt the PV cell area.
NOTHING on Ebay comes even close.
This in itself is not a problem if you know before buying that the 400W panel advertised can only be 250W even if the efficiency coefficient IS correct and $ for $ that stacks up against other 250W panels.
Hey Rob,
Same old story, and I’m truly sorry to hear you’ve also been ripped off. The sellers can be awfully sly about it, but I always go down the route of size and efficiency results in a mathematical result that cannot be faked.
Our new 200W Renogy panels deliver 200W (and even more) when the conditions are great, so it is absolutely possible.
Take care
Aaron
Hey Steve,
That is absolutely shocking. Did you purchase it through Paypal? I always do it that way these days (still through a credit card) as you get their buyer protection. You can lodge a dispute with them (and you can with eBay too), and hopefully you have some more luck.
All the best
Aaron
I purchased a couple of flexible ATEM “250 watt” panels from a well known Ebay store.
I felt they were not charging the van as well as the rated output indicated. So I got a solar panel tester (EY800).
In Full sun on panel was putting out 83 watts and the other 110 watts… not even close to the rated 250 Watts.
At the same time my old 150 watt rated panel was putting out around 120 watts or so …
When I contacted the seller I got the usual that the angle of the panel etc affects the power. This is true, but put in full sun the panels should be putting out something at least close to the rated power. .. So the panels work.. but the output is nothing like the advertised output
So yes, I was ripped off.
I purchased a MOBI 135ah LIFEPO4 battery from eBay MOBI OUTDOOR auto-market. It only has a capacity of 29ah. I tested it myself and then took it to Battery world and they verified the result. The eBay seller won’t honor the 2-year warranty and it’s only a few months old, so now I’m stuck with it. So be careful what you buy on eBay and avoid MOBI OUTDOOR auto-market because they don’t even respond to warranty claims.
Hey Max,
I can see why you’re upset; its super frustrating. You could report them to the ACCC – they are supposed to jump on these things, but not sure how they’d go about it being on eBay
All the best mate
Aaron
I’ve definitely been ripped off so how can I go about having them prosecuted if they’re fraudulently selling these things on Ebay? I have found 4 sellers who are actually the same person and advertising Name Brands, but they aren’t! They all have one letter missing from the proper brand names. I want to see them in jail so who do I go to? Cheers
Hey Jackie,
Sorry to hear you got bitten; its becoming more and more common, and they are even more falsely advertised than before.
It really makes me angry, and I wish there was more I could do about it.
Good luck with the dispute!
Aaron
I am so glad I found this article. Bit of a newbie here and just received two 300w panels from ebay. First thing I did was put the mulitmeter on and with full sun could only get 4.99 amps
So yea given I needed 15 ish amps way out of range. The size of the panel is 930 x 540 so works out .50 and makes it about 80watts. Worst thing is that you are paying for the 300w panel, well cheap chinese panel, which is fine, I have had one for over 10 years, happy that it may not come up to the exact rated specs, but this is obviously a low watt panel being advertised as a high watt panel. I am now in negotiations with the seller. Now that ebay are offering money back, I will only give the seller ONE chance to make me an offer, after that I will be going for money back. If he/she offers me a refund that makes the panels the same cost as buying a 100watt panel then I will accept that and then go out and buy a brand name panel to complete my setup. Cheers and again many thanks for sharing your knowledge. This sort of stuff is just not on. It is one thing to understand the cheap chinese stuff will not last as long and you get what you pay for but in this case I did not get what I paid for at all.
Hey Teri,
You’d be right! You can’t even get 2000W panels to my knowledge!
All the best
Aaron
Hey Andrew,
Yep, a multimeter works great if you can get the panel in your hands. Unfortunately its often a bit late by that time, but totally agree with using Paypal; they are great for disputes.
Victron make really good gear; you’ll be pleased with it.
All the best
Aaron
Hi, great article & I took have been through the dodgy eBay solar panel thing. Rather than all the maths, I found the easiest way to check a panel is to check it’s short circuit current with a simple multimeter. Yes, conditions can vary but if you test it side by side with a known panel then you have accounted for the relevant conditions. Also, only pay through PayPal as it’s easier to get your money back & sometimes get to keep the underrated panel as well. I have also just moved to Victron 100/30 solar controller before I saw your article so it’s great to see that I’m on the right track. Keep up the great work.
Thanks all! I’ve learnt that the 1m2 panel on Amazon for $1420:
“Rated power: 2000W
Product size: (2 panels x) 1160*530*25mm
Module efficiency: 20.3%”
seems to have added an extra zero to the wattage!
Thanks again
Hey Damian,
I can’t believe nothing can be done to stop the false advertising. You are probably one of thousands who’ve been caught up in this, and it really sucks.
A good result for you though; often the sellers are extremely unhelpful when you go back to them.
All the best mate
Aaron
Im another victim, but at least im getting a refund. Have recently upgrqded to lithium batteries and saw some of the cheaper panels, didnt do much research but saw a bi dold rated at 360W…. when it arrived, i knew i was in trouble. My old 200w unit (which has degraded a bit) beat it by 25W connected to my old mppt. Sent the seller a fairly blunt message and he offered a refund straight away.
Hi Rick,
Did you pay through Paypal? If so, just lodge a complaint and they’ll handle it. I always go through them now.
930 x 710mm is only a 100W panel, and 700 x 670 is only an 80W panel, so it sounds like its way off what they advertise anyway.
By the way, you’ll struggle to ever get the full rated capacity from these panels, unless its a really good quality unit. Most 200W panels only put out about 150W at maximum, in perfect conditions.
All the best
Aaron
This is an email I just sent the seller of a supposedly 160 watt panel.
Hello, the solar panel I ordered is not as described.
The item was supposed to be 930mm x 710mm.
The box that it came in said that it was 770x 700 but in fact it is only 700 x 670.
Big difference between the advertised 930 x 710 and what I got, which is only 700 x 670, and will only supply 70 watts, no where near the advertised 160 watts !
This is unacceptable, and a blatant ripoff.
Will you please supply me the advertised item.
I have Pictures attached of UNDERSIZED panel but apparently they were too big to attach to this request.
Regards,
Rick Bryant
Hey Aiden,
Yep, they are all scammers, and should be fined for it. I’m glad you found it useful.
All the best
Aaron
Hi Aaron, thanks for the informative dialogue. I have found similar discrepancies in panel sizes versus claimed ratings in practically all the portable panels on offer on eBay. Nearly all of them do not advertise the actual dimensions any more and I have to contact them to get same.
I use the formula: % efficiency x 1000 x area of panel less aluminium edging. So using your example above: 24 Ă·100 x 1000 x (1.27 x .71) = .24 x 1000 x .9017 = 216W less 5% for aluminium edging so just over 200W. Only found one foldable portable panel so far that met criteria and that was Renogy. Will check out Low Energy Dev. Keep up the good work. Regards, Aidan
Hi Steve,
That is the perfect example of a very, very poorly advertised panel. At 1270mm x 710mm it will not be more than a 140W panel. Even if their ‘up to 24% efficiency’ were to be believed (which it won’t be), it can’t be more than a 200W panel. Either way, very poor form of Outbaxcamping.
All the best
Aaron
How would you rate this 350W panel & 30A Controller, believable or a scam
(Link to eBay Outbaxcamping removed)
Cheers
Steve
Hey jr23,
Yep, its a total shambles, and they still sell like hotcakes. Please share it around!
All the best
Aaron
this is January 2021 just looking today for a flex panel but the ads are even worst than you described the sellers are posting possible watts for a day in sun which cannot be accurate since time of sun is different depending on season and location. one i saw ad said 120 watt
and only $47 usd turns out it was only puts out 1.8 a so it was 120 for whole day in sun not a 120 watt panel. one change that can vary from a few yrs ago the panels have gotten smaller in some brands
Hey Dave,
Yep, I’ve heard of people not having nearly as much luck as you did.
All the best
Aaron
yeah, thanks aaron. i was lucky in that i had another 170w panel to compare against and even with that, who knows how ebay would have decided if the guy had made some case against my testing. i can see how this just ends up being the vendor denying the validity of someone’s testing and ebay not really having the technical ability to judge correctly. it would be hard to prove unless you could test a panel at standard test conditions. anyway, i agree that ebay needs to clamp down on this.
Hey Dave,
Good to hear you had a win. eBay needs to stop the sellers all together; its a joke and there must be thousands of people who’ve been ripped off, and continue to be.
All the best, and hope your brother gets good use of the other panel!
Aaron
Thought I’d post a happy ending. Bought a “200W” panel on Ebay to replace the 170W on my trailer. The seller claimed it had new technology and that’s why it produced more than a 170W of the same size. It came and I put the new 200 next to my 170 on the ground. I live in New Mexico at 2000+ meters with plenty of sun. I recorded Volts and Amps at various conditions and the panels were, of course, nearly identical. I contacted the seller, no response. I filed dispute with Ebay and the guy asked for more time to respond but he never did so Ebay awarded me the full purchase price and I didn’t have to return the panel! I gave it to my brother to put on his trailer. Works great as a 170 watt panel.
so that worked out but this poster is right on. monocrystalline are a bit more efficient so you can get a few more watts out of the same size polycrystalline panel but there’s no other magic currently available to make one panel put out lots more power than another of the same size.
Hi Blue Star,
I hadn’t seen that before. I don’t really get a say in it though, but I’ve tried to publicize this issue for a long time
All the best
Aaron
Ummm…do you realise that in monetising your blog, you are displaying solar panel adverts that are linking to the very undersized and underpowered products you are attempting to expose!?
Hey Chris,
Thanks. You are very welcome.
All the best
Aaron
Thanks, this is an excellent article.
Hey Freeman,
Yep, most are false advertised, and its shocking. I know Low Energy Developments were in talks with eBay to get them to police it (as they sell the correct size ones), but not sure if they’ve had any luck.
Absolutely grinds my gears seeing people getting ripped off every day.
All the best
Aaron
I’ve just recently bought an ebay solar panel and after testing it realised these scammers are at work. So as you have, I started shopping based on sqcm per watt.
I found that almost every seller’s panels on ebay except one (I looked at over 15-20 products) were approximately half the square centremetreage per watt, 30 sqcm/w vs 60 sqcm/w.
To get a baseline against these scammers and compare to the one seller who looked legit in size (they were the only one that in their advertising made specific mention of the size of their panels and others being smaller, so the other’s power claims being dubious) I also checked reputable bricks and mortar sellers and their panels were also 60 sqcm/w.
I raised this issue with ebay and am yet to send a comprehensive report in to their customer care. If there’s no action I’ll consider reporting them to Australian consumer authorities.
I also had this experience with buying a power bank on ebay which was half the physical size of what it should have been for its rated power storage. It performed at about 40% of what it should have as expected. With batteries and solar panels, the size is always indicative.
Hey Jeroen,
Yep, the cell sizes is what you want to look at, but in the grand scheme of things the border doesn’t make much of a difference, especially if you are comparing panel to panel.
It is super frustrating to see people not get what they ordered, or paid for. So unethical.
All the best
Aaron
Hi
Solar eff is cell eff eg 20% cell = 18% Overall (panel) eff allowing for frame & gaps b/w cells so 1 sq mtr = 180W don’t rely on sizes dimensions all vary work out sq mtr match it 2 cell eff & overall eff seen my old man order 1 supposed 200W was smaller than my 130W panel cheap but not what u pay 4
Hey Wayne,
Unreal mate. Probably vastly different to what gets made these days!
Aaron
I bought one of the 1st ever folding portable solar panels back in about 1991.
I’m sure it was from Low Energy Developments….. it was a show demo and I reckon it cost about $1,000……. had to get it freighted from Vic to WA via Greyhound bus.
It’s still lying around somewhere….. the glass shattered but still puts out current…. I should measure it?
Hey Sandi,
Good to hear. Yep, I feel sorry for those on eBay doing the right thing. eBay themselves should be stepping in and sorting it out. I’ve heard from so many people who have been ripped off through this.
All the best
Aaron
I bought my 100w solar panel off eBay sum yrs ago, it’s German made n has s life time warranty on it n is working great ,I think U need to see where it’s made n research the in’s n outs of it ,thanx for this article good read ??
Hey mate,
Yep, pain in the backside. If you buy through Paypal they will honour their money back. Still, a process you shouldn’t have to go through
Aaron
great article.
unfortunately ebay has become a paradise for scammers, since ebay is not accountable and their money back guarantee is not worth the memory in bites (paper its written on)
Hey Rick,
Yep, not uncommon, although that seems a bit excessive. Can you get a refund?
Aaron
Bought 250 watt solar panel from so called reputable dealer and after checking measurements our panel equates to 120 watts have been well ripped off.
Thanks Aaron for getting back to me. I think I will go with it as the price is fair and you reckon it’s ok
Hey mate,
I’d say it is correct; Low Energy Developments are great.
Aaron
Hi Aaron. Is this panel ok. It is a bit smaller then the m2 for the wattage you mentioned above.
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com.au%2Fulk%2Fitm%2F332630523731
Thanks
Matt
Hey Garry,
Still under $1 a watt. Look up Low Energy Developments – they sell reasonably priced panels that are the correct size
Aaron
So what sort of price should I be looking at for a reliable 200 watt panel which is what it says is please?
Hey Rod,
I’m sure some quality ones do perform better, but also last longer. That said, there’s certainly a market for cheaper panels. I would bet a huge number of panels sold in Australia and used for many years without issues are the cheaper ones. I have 3 of the 200W solar panels from Low Energy Development that are several years old and have been hammered. Very pleased with them so far
Aaron
I measured a brand new kings and a brand new baintech, both 120wat. Baintech put out 15% more power. We’re both measured twice one after the other in same location as long as it took to change leads, no clouds.
Neither eBay but quality vs cheap.
Poor man pays twice or whatever he saying is.
Hey Anthony,
Sounds like you’ve got it nailed mate. There are very few 200W panels on eBay that are actually true. The Low Energy Developments buck this trend, and I’ve got 3 that I’m very pleased with.
The flexible panels, from what I have heard are not as reliable as the fixed ones especially when fixed with a limited gap underneath
Take care
Aaron
Interesting article, prompted me to do a bit of further research and maths.
Assuming full sun is 1000W/m², you can get the efficiency with the formula: Efficiency % = Panel Power / (Area m² x 1000)
Which suggests a lot of the 200W+ panels on ebay would have to be in the vicinity of 25% efficiency.
However, picking a random 120W flexible panel at 0.67m² (calulated 18% efficiency, which is a more reasonable number anyway). If we work back based on 15%, that gives us a 100W panel, which for the price is still pretty good ($99 for the one I’m looking at)
Is there anything else we should be looking out for?
Hey mate,
Sounds like a sales person just trying to fob you off. I don’t suppose they have a physical store here? If you purchased it through Paypal they are usually pretty good with helping out
Aaron
Just for the record the generator is a Gentrax 2kw. At maximum load it blows so much smoke that it chokes and stops. Their fix is to only put half the oil in. Admittedly the low oil alert if it works does not shut down the generator. The problem seems to be the crankcase ventilation valve does not work. A new one lasted five minutes. Ebay are no help. I thought oil splashing around the sump lubricates the cylinder walls. With half the oil this process is going to be less then optimal.
Hey Robert,
Sorry to hear you’ve had a bad run. It is a right pain in the backside!
Aaron
Ebay won’t help a small buyer when they get lots of sales /fees from a corrupt/dodgy seller. They would be shooting themselves in the foot. Ebay can’t be considered ethical in these cases. EG. I bought a cheap 2kw inverter generator. It comes with 12months warranty. After 4 months there was a problem. Ebay would not let my original line of communication continue so the seller could not easily follow our past communication trail. Even though I use Ebay I hate Ebay. I try to use Aliexpress as much a possible because of Ebay practice. It would be good if others could follow to punish Ebay. It is the only thing they will understand.
Cheers for your comment Siam.
MPPT’s certainly have their place
Aaron
It must be noted that a PWM charge controller will only get you about 60% of the panels power as compared to an MPPT. In practice, your typical 250W panel (Nominal voltage = 12V) in full sun will only deliver 11A @ 13.8V (ie. about 150W) with a PWM charge controller after normal losses due to temperature (Google “I-V curves” for solar panels). To get the remaining 40%, you have to get a MPPT controllers which usually costs more that 40% of a 250W panel. MPPT controllers however are usually only used on larger systems for this reason & where you have a miss match of panel voltage to power (ie. 24-35V panels charging 12V batteries or panels connected in series [ie. up to 600V] to maintain minimal current & power losses).
Hey Richard,
You can (and people do) spend hours arguing with the sellers. They will just say that their panel is more efficient, and that you only get their current ratings under certain conditions. These days, you will struggle to find panels on eBay that are not false advertised. It really is terrible. Of course, this excludes the quality, well known (and expensive) brands.
Aaron
Hi
Perhaps it is time to start a “Lemon suppliers of eBay” and name them there. As long as the facts are correct and you can prove that you have tried all the avenues of redress. Have you tried reporting the eBay shop to eBay. Fraud is fraud.
Regards
Richard.
Hey Paul,
Sorry to hear that mate. It’s become a real problem, and I feel sorry for everyone getting ripped off
Aaron
ITs the same with there generators, a 2000watt one can only give about half that. I also bought a 3hp pump that only draws 1200w go figure thats about 1.5hp!
What I have seen all cheapo ebay panels are inflated & false advertised. Nothing you can do, there are no rules against it.
Many things are false advertised like LED lifespan hours 50,000 etc, complete utter BS & they can getaway with it as there are no standards.
The cheap panels seem to have very dodgy solar reg/controllers too. Just better off getting a victron mppt & wire it up yourself.
Hi Richard,
Good to hear they offered you a refund. Most don’t. Most on eBay are false advertised. I don’t know what more I can do, asides from sharing the article around. The calculations are solid, unless there is a major improvement in efficiency. PS – Check out Low Energy Developments. You can buy from them off eBay and they are the correct size panels.
Aaron
Hi.
Received a replacement solar panel from a supplier and did not add up. Measured with my watt meter and max was 82w from a 160w panel. Wrote and complained and got the normal run around. Then came across your article and quoted them the numbers and immediately they offered a return. Currently travelling so not possible. However I then started looking at the eBay panels and cannot believe that almost every one is wrong? I checked with shop front suppliers and their numbers added up. Back to eBay and all are wrong. It is unbelievable. Surely we should be able to report them or something…many, many people are being duped.
Thanks for the article
Regards
Richard
PS – youbcertain about your calculations? 🙂
Hey Jan,
Yep, it needs very specific conditions.
Aaron
Cant go wrong with the basic math to prove its false advertised. However from my observations you still loose around 15-20% panel wattage in many places depending on season. For example my 100watt by area panel only gave 80watts no matter what i did in spring victoria.
Hey mate,
I do completely understand what you mean. It’s pretty straight forward – ask them how one supplier sells a panel thats substantially larger with identical specifications. It doesn’t compute – you can’t physically reduce the size of a panel without increasing the efficiency.
Redarc are very reputable, and should have the same efficiency specs as your eBay ones
My brother went through the same process and they didn’t want to play ball. Eventually he did get some money back, but it wasn’t much
Aaron
Hey mate, thanks for your reply.
I’m thinking about using that formula to justify my bid to get my money back and/or get an extra panel from a supplier on eBay based on the false advertising. I just wanted to ba able to cite the information from somewhere a bit more “official” rather than a from website blog that I read. Hope you understand what I mean!
Cheers. Love ya work.
Sam.
Hey mate,
From memory Redarc and a few other reputable suppliers. Any reason you are asking?
Cheers
Aaron
Hey mate, where did you get the info from regarding the ratios of metres squared to wattage?
Cheers, Sam.
Hi Kevin,
Like everything in life, there are different qualities. Solar panels can have different efficiencies depending on what they are made of, and how they are made. They naturally lose efficiency over time, but the cell efficiency quoted when new is how well they convert light into power.
Aaron
Hi , what does cell efficentcy mean , you say between 17/20% ?? , cheers Kevin
Cheers Marcus. Will fix that!
Aaron
Excellent article – I’ll be saving his one. Thank you. One further ‘picky’comment, you spelled the abbreviation for mathematics wrong – its ‘maths, not math’. We’re still in Australia aren’t we?!