The price of commercially made solar panels on eBay is around $1 per watt and have been for a few years, but the price of individual solar cells are likewise at a low price per watt, around $0.48. Looking at those prices, it’s tempting to say that it’d be cheaper to just buy the solar cells and put together your own panels. But is it? Simply adding up all the costs might seem like a good way to tell, but you’d need to make a panel to really see what works and what doesn’t.
| Part | US$ | Euros € |
|---|---|---|
| solar cells | 53 | 45 |
| aluminum U-channel | 20 | 17 |
| plexiglass | 43 | 37 |
| adhesive | 8 | 7 |
| clear epoxy resin | 40 | 34 |
| Total | $164 | 140€ |
And so [GreatScott] did just that, with his own side-by-side comparison. He made a 100-watt solar panel and mounted it on his roof beside his commercially produced 100-watt one and compared their output.
The cost of his DIY panel rose quickly. To make a somewhat comparable panel he needed to buy aluminum U-channels, clear epoxy resin, and more. Shown here is the breakdown of his costs.
His commercial 100 watt solar panel would cost him $103 today (87.90€). Compare that to his $164 DIY panel. Also, his DIY one likely won’t weather as well as the commercial one and may not handle high temperatures as well either. You can see the results of his testing in the video below, along with all his construction steps.
Another component open to DIYers in a solar system is the charge controller which takes the solar panel’s output and uses it to charge the battery, with added features like MPPT. Check out this DIY charge controller with MPPT and WiFi for data logging.
If you live in the midwest check out Fred480v on ebay… quite often he has panels new panels with warranty for under 50c/watt I pick them up from his Michigan City location and have gotten as low as 28c/watt for B grade. Way cheaper and easier than DIY… he’ll also show you around the place where they make 12v and 24v panels for RVs and such.
Does Fred have a website outside Ebay?
Plexi and epoxy are both an impressive part of the BOM. Commercial panels are air sealed in the plastic layer, not glued (source : How it’s made https://www.youtube.com/watch?v=qYeynLy6pj8). Plexi could also have been 1/3 thickness (1mm) for easily 20$ less. There might be ways to make this process DIY and economically viable, but this isn’t one.
A lot of the panels I have seen use tempered glass to resist hail. Acrylic does not weather or take sun well. Even glass solarizes over time.
Cheap solar lights are usually like that.
Ugh tell me about it. I bought 3 sets of solar xmas lights to dress up a conveniently xmas tree shaped tree in our yard to impress my 2 1/2 year old daughter. All but 1 of the panel turned to a frosted mess.
I know HAD readers i should not buy off the shelf. This year I’ll chop those LED strings off of there panels. use a nice big 12V panel and SLA for store and supply and drive those LED strings from a thing I make that does stuff.
Don’t forget the 555!
B^)
I pay a less than that for generic acrylic instead of that Brandybrand(TM) stuff listed, but I also avoided the expensive epoxy by encapsulating the cells (and bonding them to the acrylic) with some EVA film. If you don’t have a lamination machine, then it is hard to do and requires a certain amount of technique; basically, partially heat and stretch it into position, before pressing it into place. Then when it is tacked together, heat it up some more to melt it into place. Being a human lamination machine is easier than cake decorating, but still hard.
DIY is always more expensive if you’re choosing the easy construction methods and also want any build quality. Saving money is going to involve some hard work or investment in tooling. I’ve watched a lot of GreatScott’s “DIY or Buy” videos, and the answer is always “buy” because he doesn’t put the work into the DIY option to make it higher quality. DIY can win when you want something really nice without paying as much, but it isn’t going to win for the cheap stuff unless you’re using salvage or discount parts. His straight build videos are higher quality, but of course when the “buy” option is donated it is hard for it not to somehow win.
I would like to see a “DIY or Buy” for a MPPT controller. I would expect DIY to be the winner, since the cheap MPPT modules are not very good.
agreed, i’ve been through too many MPPT’s , cheap ones blow IC’s and caps, expensive ones just release the blue smoke inside the IC with no part number. Why do they break so easily (compared to my 20yr old RV solar unit)
One thing to remember with MPPT is that as the cost of solar panels drop, the power point at which MPPT makes sense goes up. Simply put, a MPPT can give you 25% more power, if space and size is not an issue, for small systems it is usually cheaper to just buy 25% more panel.
Wonder if some improvements can be made like backing the panels with an exchanger carrying heat off to say a water heater? Not to mention tiny Fresnel lens to boost the amount of solar each gets.
Hybrid PV & hot water cells are commercially available:
https://dualsun.fr/en/product/2-in-1-solar/
The Fresnel lens thing has been done too, but it only works well in direct sunlight.
How about the labor costs? I once calculated the money saved for a DIY panel to be about fifty cents per hour for the labor spent. Better to let machines do that work.
Ahhh… but think of all the labor cost (from NOT watching television) he has saved! Because while you watch television you could have done something productive. You could even state that television costs our economy a lot of money… however… we don’t! Proven that spare time or hobbies have no labor cost.
In fact by doing something yourself… you save labor costs… because you are not paying somebody else to do it for you!
So in short hobbies don’t have labor costs… if you do this to save money you do this because you like to do it OR because you think you can do it better then the commercial ones. The latter clearly isn’t the case for this build, but I’m pretty sure that this may vary from person to person.
Except this article did not frame building panels as a hobby, or as doing it better yourself. It framed it as whether it saves money. In calculating the money savings, labor costs absolutely must be considered.
This same math has people camping out in front of Best Buy a week before Black Friday in order to save $500 on a TV. That “hobby” pays at $2.97/hour. The person could have flipped burgers all week and slept in their own bed at night and still had more money in the end.
Hey, maybe they enjoy the hobby of living like the homeless for a week. Grin. But they shouldn’t kid themselves saying it’s a good way to save money.
And that’s my point about this article, as well.
A 100W solar panel with questionable acrylic front (instead of glass) and probably yellowing epoxy for 140€? Some weeks ago my brother payed 138€ (+taxes) for a 270W panel. So even if I would not count labor cost, when I do something as a hobby, It is no fun to produce an inferior product for a much higher price than a bought one.
Generally, for things which are produced highly automated DIY normally does not make sense.
Old saying:”Linux is only free if your time has no value” by Jamie Zawinski. Substitute solar panel for Linux for much the same effect.
I don’t see how that stands up considering how much time you have to spend clicking “OK” with Windows
or waiting for windows to reboot after updating every time you use it (ok, I almost never turn on my windows machine… but every time I do…)
If you use epoxy to encapsulate your solar panels, you’re gonna have a bad time! Nearly all epoxies will yellow in UV, most rather quickly. There are UV resistant epoxies that won’t yellow as fast, but those are balls expensive.
Put UV-blocking filter foil on it?
epoxy was on the back, fronty is plexiglas
Agree, How long you want these panel to function? Days, Months or Year? If you want them last >year. Its is a good idea to buy a laminated PV module from manufacturer.
You can get solar panels for less than 50 cents per Watt from renvu.com.
International spot prices are much lower, however. Panels are as low as 23 cents per watt, and cells are just 12 cents per watt. pvinsights.com
I don’t think people have fully realized the consequences of prices this low. Price per kWh installed could (with appropriate automation) reach under 1 cent per kWh over 25 years (the cells themselves accounting for just a quarter of this), meaning you can install enough solar panels to still provide electricity on cloudy days and with battery backing during nighttime while still being cheaper than fossil fuels.
SunElec has them for 41 cents per watt at the moment but they have had prices in the 30 cent range. Been in business at least ten years.
http://sunelec.com/home/
Today, the most expensive part of a solar panel setup is not the solar panels. It’s the electronics, knowledge, wiring, troubleshooting, etc.
Cell quality and performance may fluctuate with that price.
The Blog is very informative and helpful. I had many queries regarding this but here I found solutions and the comment section was also helpful for me That’s why I am commenting here to say thanks to all.
Thanks for tackling this issue! Commercial ones are really quiet expensive but can’t argue with the quality. Thanks for the video, picked a lot of tips!
Thanks for conducting this experiment and sharing the results! I have been planning to install solar panels as well, and I was wondering whether I should just assemble on my own or buy commercial ones. Basing on what you have find out, I guess, I should just got for the commercial ones.