Is price always the first consideration in solar panels?

[Chester Gal]

I have 2 local options to purchase solar panels. Huge price per watt difference.

$85.00 USED Hanwha Qcell 330 watt polycrystalline, 72 cells, used for 2yrs industrial grade, VOC 46.55 ISC 9.49

$175.00 NEW Canadian Solar 385 watt Bifacial, monocrystalline, 144 cells VOC 48.0 ISC 10.09

At first glance, this seems to be an easy choice. Total newbie here. I will be buying 12 panels to start. Ground mount. Both sellers have lots more panels to buy more in the near future. My situation is that I live in SC woods, surrounded by extremely tall long leaf pines. I have been monitoring the sun now that it's almost winter. The pines block the sun so I only get 3/4 hrs full sun in the best location. There is on/off shadowing throughout the day. Plus I'm still 2 mos away from winter solstice. My question is will the bifacial panels be a better investment in the long run for my winter low light situation? No snow here and the array will be pretty close to the tree line. Is it better to just buy more of the used panels? Then I have to take into account the cost of more racking. I'm building my system a little at a time as I can afford it and don't want to make an expensive mistake. Which of these panels would you buy and why?

 

[littleharbor2]

Sounds like you'll be highly disappointed regardless which panels you buy. Solar panels performance drops substantially in shady conditions. Typically you would series wire your array. A single shadow on a single panel will kill the output of the entire array. Solar may not be a wise investment till you can find a sunny location to mount them.

 

[drps10]

My situation is that I live in SC woods, surrounded by extremely tall long leaf pines. I have been monitoring the sun now that it's almost winter. The pines block the sun so I only get 3/4 hrs full sun in the best location. There is on/off shadowing throughout the day.

i have no input on the question at hand, but an idea. I also have a lot of trees and shading is a concern. I have a location that I think will work well, but I am not sure about shading in the winter. Summer will not be an issue.

I bought a time lapse camera and have it mounted about 15' up and overlooking the general location of where I want the array. I have also considered to mount some on my west facing barn roof which is also in the picture frame. I am giving it 8 months run time and set it to take a picture every 45 min. Then I can see how bad the shading will be and can also see where a better location could be. I wanted to see the shade progression without having to take a picture everyday with my phone. And there are instances where it's cloudy for days at a time and I didn't want to forget. I will look for the camera model if you want (couldn't find the purchase in my email), but that battery life for every 45 min is like 6 month if not more.

This allows me time to do more research, prices to come down/product to improve and determine if this is the best option.

 

[Chester Gal]

Sounds like you'll be highly disappointed regardless which panels you buy. Solar panels performance drops substantially in shady conditions. Typically you would series wire your array. A single shadow on a single panel will kill the output of the entire array. Solar may not be a wise investment till you can find a sunny location to mount them.

There's the problem! In late spring, summer and early fall, when the sun is higher, I have more sun than I can use. I need advice for winter.

i have no input on the question at hand, but an idea. I also have a lot of trees and shading is a concern. I have a location that I think will work well, but I am not sure about shading in the winter. Summer will not be an issue.

I bought a time lapse camera and have it mounted about 15' up and overlooking the general location of where I want the array. I have also considered to mount some on my west facing barn roof which is also in the picture frame. I am giving it 8 months run time and set it to take a picture every 45 min. Then I can see how bad the shading will be and can also see where a better location could be. I wanted to see the shade progression without having to take a picture everyday with my phone. And there are instances where it's cloudy for days at a time and I didn't want to forget. I will look for the camera model if you want (couldn't find the purchase in my email), but that battery life for every 45 min is like 6 month if not more.

This allows me time to do more research, prices to come down/product to improve and determine if this is the best option.

Wow! That is a great idea! I've been doing it by eye and just trying to remember but to have it "documented" would be great. Yes! Please! Any info would be great. Thank you!

 

[SparkyJJO]

Winter is always hard if you don't have a grid to fall back to. What typically seems to happen is if you build out solar large enough to cover winter, you'll have energy coming out of your ears in the summer. Shame there isn't a real good way to save all that summer energy and use it in the winter instead.

 

[Chester Gal]

Winter is always hard if you don't have a grid to fall back to. What typically seems to happen is if you build out solar large enough to cover winter, you'll have energy coming out of your ears in the summer. Shame there isn't a real good way to save all that summer energy and use it in the winter instead.

Luckily I do have the grid to fall back on. Thanks for the comment!

 

[Solarcabin Channel]

$85.00 USED Hanwha Qcell 330 watt polycrystalline, 72 cells, used for 2yrs industrial grade, VOC 46.55 ISC 9.49

$175.00 NEW Canadian Solar 385 watt Bifacial, monocrystalline, 144 cells VOC 48.0 ISC 10.09

You are comparing apples and oranges.

Poly panels are older type panels that were used before mono panels became affordable.

They work and can even work better than mono in low light conditions but poly panels have a shorter lifespan and more significant drop off in production.

"Mono panels can last 30–40 years with optimal care and maintenance. Poly panels last 25–35 years with proper upkeep."

Monocrystalline vs. Polycrystalline Solar Panels (2024 Guide)

Confused about the difference between monocrystalline vs. polycrystalline solar panels? Read our detailed guide to learn how they compare.

www.thisoldhouse.com

Bifacial panels are a new technology and more expensive per watt than a typical mono panel of the same watts. They need a reflective surface on both sides to see the benefits and the testing I read is still inconclusive as to long term benefits.

Where are you finding bifacial 330 watt new for $175 as a price check shows those at around $300?

 

[littleharbor2]

There's the problem! In late spring, summer and early fall, when the sun is higher, I have more sun than I can use. I need advice for winter.

So, 6 months of no shading? If so then if that is fine with you, go for it. Just keep in mind what I mentioned regarding shadowing on your panels.
What are your plans for your battery bank? different chemistries will need different care when not being used. Will this property be in use year round?

 

[Chester Gal]

You are comparing apples and oranges.

Poly panels are older type panels that were used before mono panels became affordable.

They work and can even work better than mono in low light conditions but poly panels have a shorter lifespan and more significant drop off in production.

"Mono panels can last 30–40 years with optimal care and maintenance. Poly panels last 25–35 years with proper upkeep."

Monocrystalline vs. Polycrystalline Solar Panels (2024 Guide)

Confused about the difference between monocrystalline vs. polycrystalline solar panels? Read our detailed guide to learn how they compare.

www.thisoldhouse.com

Bifacial panels are a new technology and more expensive per watt than a typical mono panel of the same watts. They need a reflective surface on both sides to see the benefits and the testing I read is still inconclusive as to long term benefits.

Where are you finding bifacial 330 watt new for $175 as a price check shows those at around $300?

The bifacials are 385 watts and they are listed on local facebook. I just saw he has them also listed on ebay as full pallet sale. The great price is why I'm asking if they are worth the investment as opposed to the much cheaper used 330 watt panels. I can get the links for you if you want them.

 

[Solarcabin Channel]

The bifacials are 385 watts and they are listed on local facebook. I just saw he has them also listed on ebay as full pallet sale. The great price is why I'm asking if they are worth the investment as opposed to the much cheaper used 330 watt panels. I can get the links for you if you want them.

I am very skeptical of that price for new bifacials and FB has lots of scammers.

Buyer beware!

 

[Chester Gal]

I am very skeptical of that price for new bifacials and FB has lots of scammers.

Buyer beware!

It's true FB has a lot of scammers but I don't think this is the case here. This is a brick and mortar business that specializes in new and used computer and electronics. He had an opportunity to buy quite a few pallets of these panels and is now selling them singly and by pallet.

 

[littleharbor2]

Always beware of scammers. OTOH check out the 385's If they are what they say they are I'd buy them. Now that panels are up in the 550 watt range those "new" panels aren't really new and that sounds like a good price. I just bought 550 watt panels for $250 recently.

 

[Chester Gal]

Always beware of scammers. OTOH check out the 385's If they are what they say they are I'd buy them. Now that panels are up in the 550 watt range those "new" panels aren't really new and that sounds like a good price. I just bought 550 watt panels for $250 recently.

Exactly! Everyone is moving up to higher watt panels as the price comes down. So you think the new 385 watt bifacials are a better buy than the used 330 watt at almost twice the price per watt?

 

[Chester Gal]

New 385 watt bifacial panel $.45 per watt
Used 330 watt panel $.25 per watt

 

[NC_hydro]

A chainsaw would solve your wintertime shading issues. And as a bonus, you could have lumber made from them.

 

[Chester Gal]

So, 6 months of no shading? If so then if that is fine with you, go for it. Just keep in mind what I mentioned regarding shadowing on your panels.
What are your plans for your battery bank? different chemistries will need different care when not being used. Will this property be in use year round?

Yes year round. Grid back up but not tied to it. Batteries so far are 2 LiFePo 48V 5000W 100Ah but will be getting more as I can afford the. Do you have any advice about which panel is the better buy long term?

 

[Chester Gal]

A chainsaw would solve your wintertime shading issues. And as a bonus, you could have lumber made from them.

AH yes! It would only solve part of my issues. I plan to have some of the trees logged out next year. Too many, too close together to do myself. That would be SW and W directions only. E and S is not my property. House was here when I bought the land and built in one corner of property.

 

[littleharbor2]

New 385 watt bifacial panel $.45 per watt
Used 330 watt panel $.25 per watt

If you have space for less efficient panels then, hard to go wrong with 25 cents a watt. Being that you won't likely have warranty coverage on either than I'd go for the 330's. My point on the 385's was that they didn't seem like a scam to me.

 

[Chester Gal]

If you have space for less efficient panels then, hard to go wrong with 25 cents a watt. Being that you won't likely have warranty coverage on either than I'd go for the 330's. My point on the 385's was that they didn't seem like a scam to me.

Thanks for that advice! That's what I was originally thinking. I just had second thoughts that I might be missing something with the other panels making them a better buy somehow. Thanks for taking the time. These days every cent is precious and I don't want to make a costly mistake.

 

[pvgirl]

Your price per watt comparison should include costs of mounts for panels, and any shipping/delivery costs. Spending more on mounts, materials, and equipment to install more cheap panels vs. installing fewer cheap panels may not make sense.