Budget system, 4000-6000 watts of solar... 250w used poly panels? or New Canadian Solar 390W 144 Half Cell

[ericfx1984]

The used panels are 250w poly and $63 per panel... from santan solar... the new ones are 390w, half cell bi facials, BUT $180 per panel... Thoughts?

 

[ericfx1984]

The more i look at this, the more i think that the used 250w from Santan Solar makes the most sense. I mean even Will Prowse has a lot of love for them.

 

[Steve_S]

Consider that 1/2 Cut cells work much better in low light & shade conditions. Low Light also includes shading from cloud cover etc.
One of several articles / whitepapers & more.

Shade And Solar Panels: What You Need to Know - Solar Gear Guide

Shade And Solar Panels: What You Need to Know. Find out if solar panels will still work in the shade.

solargearguide.com

 

[gray webber]

The used panels are 250w poly and $63 per panel... from santan solar... the new ones are 390w, half cell bi facials, BUT $180 per panel... Thoughts?

I know very little of the 250 watt panels?
I just got 445 Canadian Solar bi-facials for an off grid camp system this summer.
I have run many spot tests of them at my shop and found up to over 670 watts from them! Wow- they can really put out.
Maybe not worth the extra $ but factor in your bad weather needs and overall outputs and number of panels?
At 268$ each plus shipping I have seen up to .40$. Per watt. Yikes! That’s good.
Or .60$ per wall at base rated output.
Good luck!

 

[HRTKD]

Bifacial panels aren't worth the extra money unless you are willing to spend the extra time and money to create a mounting system and background that optimizes the bifacial nature of the panels.

For example, bifacial panels on the roof would be an absolute waste of money.

For me, the choice of panels would be what I can locally to avoid shipping versus what I can find heavily discounted to make up for the high expense of shipping.

 

[ericfx1984]

Bifacial panels aren't worth the extra money unless you are willing to spend the extra time and money to create a mounting system and background that optimizes the bifacial nature of the panels.

For example, bifacial panels on the roof would be an absolute waste of money.

For me, the choice of panels would be what I can locally to avoid shipping versus what I can find heavily discounted to make up for the high expense of shipping.

So the cheaper 250w panels make more sense to you?

 

[DThames]

Santan Solar normally has a wider variety of better panels than they have been offering the past few weeks. I have bought both new and used panels from them. This one (used 310w for $80) would have my attention if I was shopping today. Shipping is not too bad if you buy more than a few.

 

[HRTKD]

So the cheaper 250w panels make more sense to you?

It depends on if you're going to install the bifacial panels correctly to take advantage of the bifacial nature. If you're going to install them like any other panel then the 250 watt panels are likely a better way to go. It depends on how many watts a bifacial will produce when the sun is only on the face and nothing on the back.

 

[iamrich]

How much real estate? If space is not an issue, I really don't think you can beat the 250w panels. The mounting costs are a factor, but with the 250w panels you can just keep adding strings for a pretty low cost.

Sadly those $63 panels were $33 a year ago (I got 12, wish I had got 120).

 

[Steve_S]

Depending on your installation plans, also consider the size difference with the panels, lots of folks forget that detail, and sometimes that can be a problem

The ideal installation is on a Ground Mount with 4 position adjustable for the 4 seasons (Depending on your location etc of course) and this can work well with Bi-facial Panels as you are off the ground and the background can be managed to get the benefit.

If intended for a roof then year round optimal angle and bi-facials can work are but far more complex, like needing a white roof underneath and spacing etc... plus again location (snow etc issues) Poor angles etc can be "carefully" compensated for by over paneling BUT with care !

The best decision has to consider how your are installing, how much real space you have available, optimal angles, and how to best achieve that and/or how to compensate for that. Also how the panels will be wired to achieve XXX Voltage & Wattage Limits for the solar charging system. The amount of panel is dictated by the amount of energy required to charge your system & supply your needs. * Getting a couple of extra if being shipped and if they are cheap may be a worthy "insurance" and if not needed, there is always uses for a couple of nice panels ;-)

Used SST Series 310W 72 Cell Poly Solar Panel
Dimensions: 77 in X 39.05 in X 1.57 in

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Canadian Solar 390W 144 Half Cell Bifacial Solar Panel
Dimensions: 83.9 x 41.3 x 1.2 in

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SanTan Solar T Series 250W
Dimensions:64.95 × 39.05 × 1.37 in

 

[Bvillebob]

I've got 40 of Santan's 250 watt used panels up, they work fine, but they are an older panel and are relatively large and heavy for their output compared to more modern panels. I have seen an average of about 220 watts in full sun from them in my installation. For my nw array I bought 24 of Santan's new REC 370 watt split cel panels, pretty much state of the art panels. They're only about 2 inches longer than the 250's, the same width and noticeably thinner and lighter making them easier to work with. They were a bit more expensive per watt, but it's nice having new panels and only needing 2/3 as many to make the same power.

If you're on a really tight budget the 250's are great, no problems with any of mine, but for an extra $50 or $75 per panel you might find upgrading to some more recent panels worthwhile if you can afford it. In the big picture of the total cost of the system, it's not a big expense.