Solar Panels Brands - does it matter?

Good point.

2x 270W 65*39” Solar Blvd panels ($202 ea) and MS MPPT 45 controller: 540W, 35 sq ft, $1272 or $2.36/W cost.

4x 140W 59*27” Solar Blvd panels ($139 ea) and MS PMW 45 controller: 560W, 44 sq ft, $1221 or $2.18/W cost.

3x 270W 65*39” Solar Blvd panels ($202 ea) and MS MPPT 60 controller: 810W, 53 sq ft, $1588 or $1.96/W cost.

CA Traveler wrote:
2x 270W 65*39” Solar Blvd panels ($202 ea) and MS MPPT 60 controller: 540W, 35 sq ft, $1382 or $2.56/W cost.

IMO you could easily go with the 45 amp controller with these two panels.

24V panel manufacturing has narrowed the cost between MPPT and PMW. For my rig:

2x 270W 65*39” Solar Blvd panels ($202 ea) and MS MPPT 60 controller: 540W, 35 sq ft, $1382 or $2.56/W cost.

4x 140W 59*27” Solar Blvd panels ($139 ea) and MS PMW 60 controller: 560W, 44 sq ft, $1277 or $2.28/W cost.

3x 270W 65*39” Solar Blvd panels ($202 ea) and MS MPPT 60 controller: 810W, 53 sq ft, $1588 or $1.96/W cost.

This includes all of the installation hardware.

steveexplorer wrote:
I am looking to buy 200-300 watts of solar panels to charge 200-240 ah of battery storage. Researching panels on the web, it seems that prices for solar panels have a very wide range. Putting aside the cheapest and potentially ineffective panels, are there reliable and effective modestly priced panel brands

Yes and no. Cheapest usually means new, unknown, domestic Chinese "brand" that nobody heard of until few weeks ago, but there are sometimes bargains on reputable brands if reseller wants to move it for some reason. Prices vary more from store to store, than from brand to brand.

I prefer to know what I am buying. Panels work better when they are matched to one another, with all the parameters close. Unknown brands will have unknown range of discrepancy in parameters.

There is also a lifespan issue. They all work - usually, and they all lose power with time, and some lose more than others.

With prices so low today, it doesn't make sense saving a little on buying something unknown. Your time and labor are more valuable. There is about half a dozen of reputable solar stores in Ca, you may find a known brand for less than something that nobody heard of. There are reputable domestic Chinese brands as well - Trina is the first that comes to mind, priced competitively but you won't find it extremely cheap. Good things cost good money.

Another matter - besides the brand - is 12V nominal vs 24V nominal, because this usually means PWM vs MPPT controller. If the goal is to maximize the output, then MPPT is the way to go. If the goal is to just "make it work" and to save as much pennies as possible, then PWM is the way. Whether you choose to do it MPPT or PWM way, brand and model of the controller is a lot more important than the brand of panels. Unlike in panels, in controllers there is a lot more things that can go wrong or are made wrong from the day one, or it just won't have specs that you need.

Thrilled with my solarblvd Solar Cynergy 60w panel.

Spec Isc of 3.86A, measured just over 4A while closest live isolation data showed 1000 wh/m^2 flat.

Good info on the temp effect, thanks. I am not clear on what it all means. ISTR reading here that MPPT advantage over PWM is greater in cool temps, but that is a different argument from being able to get enough voltage at the batteries to charge them at all in hot temps (I think (: --- ) whatever the controller type or panel rated voltage.

Doesn't take long to get all tangled up in this solar stuff! :)

BFL13 wrote:
I don't think Vmp and Imp have any meaning wrt "12v" panels. The IV curve is for Isc and battery voltage. Voc in the 21s by rating. If those panels were in series with MPPT, then their Vmp might matter, don't know.

There used to be 32 cell panels which did not have enough voltage to charge 12v batteries to 14+v but the 36 cell panels do have enough.

Not taking into consideration the difference of cell voltage v/s temperature. I have measured many different panels under various temperature situations....

Example below shows the effects of temperature and how voltage decreases the hotter the panel gets. Yes the current almost remains constant but voltage does not. When you multiply the number of cells.... 36 X the voltage at different temperatures you realize that the panel voltages will vary almost 3 volts from 75 deg F to 140 deg F... I have measured many panels while "working" and the ambient temperature is in the 70-90 deg F range... I see over 140 deg F and that voltage drops like crazy....

3 volts difference on the panels make a big difference with PWM and MPPT.

I don't think Vmp and Imp have any meaning wrt "12v" panels. The IV curve is for Isc and battery voltage. Voc in the 21s by rating. If those panels were in series with MPPT, then their Vmp might matter, don't know.

There used to be 32 cell panels which did not have enough voltage to charge 12v batteries to 14+v but the 36 cell panels do have enough.

smkettner wrote:
I would primarily shop by price, voltage, dimensions, and wattage depending on your individual needs and circumstances. Watch the shipping on large panels. Local pick up might be worth the effort. Last criteria would be what brand.

I also bought mi primary equipment at www.solarblvd.com Norco, CA

For some folks that do not have the room on the roof should shop dimension first. Get up on the roof and measure your avail area.
Truck Campers and smaller Mhomes etc do not have enough room for wide panels.


I would not consider a panel that has 17.0-17.1 Vmp for PWM controllers. ISC is important but you do need that voltage difference between the battery and panel VMP to produce the current especially when the panels are HOT.
Nor would I consider anything under 17.8 for Mppt.

I too really like Solarblvd.. Excellent service and price.

Jim

I did see a loss in amps at the battery bank from at the panel depending on how I rigged up my portable panel(s) Some set-ups were better than others of the several ways I had them this summer.
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Construction might even be a thing to look for. If the frame is thin and narrow, light weight, the panel can flex a lot, which might be unsat for certain mounting arrangements. There is quite a variation when noting weight per watt of a panel. Also for the length width ratio. Not all same watt panels the same shape.

I don't know if all the weight diff is in the frame either. Perhaps the heavier panel for same watts has thicker cells too, no idea.

Also no idea if that would matter for performance. ISTR some have the strip pattern sort of photographed on top, while others have the strip pattern connections buried deeper in the cell, which is supposed to be better quality.