yes santan
Need some advise regarding my first build.
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sunshine_eggo
Happy Breffast!
LOADS of people have bought from SanTan. Worth checking out their website. They also offer dirt cheap used panels.
what did you hear are they trash?
It would work with my 24v battery right?
If i put them in series like 4 panels the voltage going to add up the current stays the same correct so if it has a
- Rated Power: 300w
- Open Circuit Voltage (VOC): 39.85V
- Max Power Voltage (VMP): 32.8V
- Short Circuit Current (ISC): 9.71A
- Max Power Current: 9.16A
- Maximum System Voltage: 1000V IEC
- Fuse Rating: 15A
- Weight: 41 lbs
- Dimensions: 65″ x 39″ x 1.5″
9.16A?
But if i connect them in series i dont need to use heavy gauge wire but if i have shading on one panel that is going to bring down the others correct?
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if i want to put 4 in parallel to avoid the effect of shading 10A (9.71A) x4 = 40A
so this mppt would work
so this mppt would work
sunshine_eggo
Happy Breffast!
SanTan is awesome.
4P of those panels and the 100/50 would be good.
4P of those panels and the 100/50 would be good.
im surprised you say that i thought you going to say don't buy its no good...
but i am glad to hear that...
it only has a one year warranty...
if i wanna connect solar panels in series than i have to add together the open circuit voltage so that is 39.85V x4= 159V so the 150/45 victron
would not work ?
I like to have the option to choose from parallel or series connections... yes it is more expensive to have a mppt in this range ...
- Open Circuit Voltage (VOC): 39.85V
- Max Power Voltage (VMP): 32.8V
- Short Circuit Current (ISC): 9.71A
- Max Power Current: 9.16A
- Maximum System Voltage: 1000V IEC
sunshine_eggo
Happy Breffast!
Few would work. Only a handful of MPPT support > 150Voc, and they get spendy.
4S might work against you unless you have LONG PV wires between PV and MPPT. There's more inefficiency in converting higher voltages to battery voltage. You might lose 2-3% efficiency vs. 4P. If you have long wire runs, you might gain that back.
Rather than 4S, 2S2P would be a good compromise.
4S might work against you unless you have LONG PV wires between PV and MPPT. There's more inefficiency in converting higher voltages to battery voltage. You might lose 2-3% efficiency vs. 4P. If you have long wire runs, you might gain that back.
Rather than 4S, 2S2P would be a good compromise.
I am looking at this sunpower panels its sized at 61"x41"
SunPower E20 327W
- Rated Power: 327W
- Open circuit voltage (VOC): 64.9V
- Max power voltage (VMP): 54.7 V
- Short circuit current (ISC): 5.98 A
- Max power current: 6.46 A
- Maximum system voltage: 600V UL & 1000V IEC
2 sets of panels in series that is 65V X 2=130V ,and 6.5 A than I connect them in paralel so the voltage stays the same 130V but the Amp goes up to 13A so I have to use a mppt a Victron 150/ 35 and if i decide to get 2 more panels of the same model put them in paralel than the Current goes up to 26A and I still can use the same charge controler....
In the data sheet it says : Nominal PV power 1a,b 35A 24V:1000W
45A 24V:1300W
Is this means I cannot use larger panels ? like 4x 327W=1308?
link :
I just have to do some research to find more info on this panels...
What is your opinion on this one?
Thanks!
sunshine_eggo
Happy Breffast!
Yes.
"35" is for charging amps, not panel amps. May or may not be the same limit on PV input.
4X of your panels:
327W * 4 = 1308W
1308W/24V = 54.5A
You would need 150/60.
No. FOUR more panels (2S2P + 2S2P) would take it to 26A. Another 2 panels in series and in parallel with the array would only add the 6.5A, so 19.5A, but this has nothing to do with the output.
6 * 327W = 1962W
1962W/24V = 82A
You would need 82A of charging current.
Nope.
No, it means that it can't use additional power from the array beyond those limits. You can panel UP TO the Voc limit with temperature margin and up to the PV current input limit. THis is called over-paneling, and it's not uncommon. You would clip power use above 1300W, but it would output 1300W for as long as the larger power array can deliver that during the day.
150/45 has a 50A PV input current limit.
You could do a 2S7P array (~130V, 45A) and still meet input limits. However, that 4578W array would never output more than 1300W @ 24V, but it would probably do it almost all day long.
IMHO, panels made by any reputable manufacturer are fine. You buy what works for your system, or you select panels and buy around it. I have 330W Talesun that I'm very happy with, but they are 72 cell panels and have a Voc of about 47V. In an array with long PV wires, the SunPower would perform better because of the higher working voltage/lower current, but beyond that, I wouldn't care.
First thanks so much to taking the time helping me with this!Yes.
"35" is for charging amps, not panel amps. May or may not be the same limit on PV input.
4X of your panels:
327W * 4 = 1308W
1308W/24V = 54.5A
You would need 150/60.
No. FOUR more panels (2S2P + 2S2P) would take it to 26A. Another 2 panels in series and in parallel with the array would only add the 6.5A, so 19.5A, but this has nothing to do with the output.
6 * 327W = 1962W
1962W/24V = 82A
You would need 82A of charging current.
Nope.
No, it means that it can't use additional power from the array beyond those limits. You can panel UP TO the Voc limit with temperature margin and up to the PV current input limit. THis is called over-paneling, and it's not uncommon. You would clip power use above 1300W, but it would output 1300W for as long as the larger power array can deliver that during the day.
150/45 has a 50A PV input current limit.
You could do a 2S7P array (~130V, 45A) and still meet input limits. However, that 4578W array would never output more than 1300W @ 24V, but it would probably do it almost all day long.
IMHO, panels made by any reputable manufacturer are fine. You buy what works for your system, or you select panels and buy around it. I have 330W Talesun that I'm very happy with, but they are 72 cell panels and have a Voc of about 47V. In an array with long PV wires, the SunPower would perform better because of the higher working voltage/lower current, but beyond that, I wouldn't care.
I find this calculator the guy has a youtube channel as well
I used this to figure out the size of the mppt and it came back with 150/60 for 4 panels ,and 150/100 for 6 panels . Based on the numbers i added there including 55F lowest temp in my area in Florida but it does not get that cold here ...
What i don't understand if it's even gets this cold it will be in the night time but there is no sun so why would it matter?
Most likely i would start with 4 panels 2S2P like you suggested , but i like to get a mppt to have the option to get maybe 2 more panels later to expend but i think it is more realisticly one more panel can I have 5 panels or it has to be 4,6,8 etc ?
It will be a balcony where the panels will be placed and the mppt will be in a closet inside about lenght of wire 32 feet total.
I will have to use a heavy gauge wire in the ceilling where I am placing it to have minimal losses...
- Rated Power: 327W
- Open circuit voltage (VOC): 64.9V
- Max power voltage (VMP): 54.7 V
- Short circuit current (ISC): 5.98 A
- Max power current: 6.46 A
- Maximum system voltage: 600V UL & 1000V IEC
- Power Tolerance: +5/-0 %
- Fuse Rating: 20 A
How many watts your 300W panel produces just curious ?
I don't see the point having more panels than what the mppt can control if i have 1280W potencial solar watts than it would make sense to use it all agree?
What number of mppt would you recomend 150/60 , or 150/100 ?
I will never have more room than for a total of 6 panels ....
That sunpower sells out fast they have only left 3 now ...ugh
The problem is the cost of the shipping it is like $320..
would be nice if someone else would needs this panels and order it together ...
but at the end i will order it anyhow once they get it in stock i hope ..
so if a panel has more cells it is better ?
Thank you
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sunshine_eggo
Happy Breffast!
6 * 327 = 1962W
1962W/24 = 81.75A
8 * 327 = 2616W
2616W/24 = 109A
The reality in both cases is your array will likely never put out maximum current unless your panel orientation and tilt are perfect. 75A would be fine for 6 and 100A would be fine for 8.
Note also that the MPPT list a maximum power that equates to peak charge voltage, like 28V vs. the 24V we use for convenience in calculation.
The coldest time of any 24 hour period is typically immediately before sunrise since the sun has been set for the longest at that moment, so there is a very good chance that your panels will be at their coldest the moment the sun strikes them and can produce a voltage spike. Here's what tomorrow morning looks like for me:
Note that the low of 25° (red line) occurs at 7am - right around sunrise.
Typical 10awg PV wire rated for 30A should be fine. No need to go overkill on the wire size. 32 feet is fairly short. 0.76% voltage drop, 110Vmp and 13A.
Typically very good; however, I have an optimally positioned array with no shading from dawn to dusk. This past week, I experienced performance spikes due to cloud edging. Clouds covering sun, panels colder than normal operation. Clouds move, full sun hits the panels and my 2970W array put out 3500W+ for a bit until the panels warmed up.
In most cases, I get 80-90% of my rated panel power. Since I have a year-round tilt my best performance is in spring and fall.
You only get peak solar output at high noon with perfect panel orientation, clear skies. At all other times, you get less than rated power. If your area is cloudy on a somewhat regular basis, over-paneling makes sense. If you have an array with a very limited orientation and tilt options, then over-paneling may be sensible. Some folks split a single array into SE and SW facing arrays in order to get more morning and evening power vs. being clustered in the middle of the day.
See above.
Are you sure that panel makes sense? You could probably order smaller panels from Amazon for $0.75-0.85/Watt - probably cheaper than shipping on the big panels.
Below I included a scetch of the layout of my balcony ..
I have two palm trees one each side
and the original plan was to have 2 panel on each side , and maybe future expand to put 2 more and place them in the middle or one more of the 327W ,do they need to be in pair?
Also can I use different sizes for those aditional 2 if i decide maybe 2 x200W panels?
So I have looked at the mppt and they are pricey the one I eyeballing is the victron 150/85 ,the next one down is the 150/70 $100 less
Option 1.
Sunpower 4x 327=1308W
1308/24=54A
Option 2.
Sunpower 6x327=1962W
1962/24=81.75A
Option 3.
4 x327W and 2x 200W Newpowa solar from amazon because it is smaller leave me with more room and place them in the middle between the 2 doors.
Sunpower 4x327=1308W
Sunpower 2x250=500W
1708/24=75A
Option 4.
Sunpower 6x250=1500W
1500/24=62A
This looks like a good panel : https://store.santansolar.com/product/sunpower-x20-250w-new/
I think the 150/85 would be a good choice for all 4 right .?
Is there a way to save on a different mppt with a different connections would i be able to choose a smaller unit or i need this because of the size of the panels etc?
I like that idea to set them up SE , SW I will also have them on a rolling stand so I can position them if I need to
if I have 6 of this how would I connect them 2S2P what about the other 2?
Sunpower 327W x 4 $0.61/Watt with shipping
Newpowa 200W x 2 $1/Watt with shipping
Amazon is more expensive most likely I will order 2 smaller panels from Santan at the same time to save on delivery .
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sunshine_eggo
Happy Breffast!
I understand the sketch is approximate, but this is what I see; all panels will fail to capture significant portions of the day's sun:
What is your latitude? Will you be able to tilt them to approximately that degree from horizontal?
Do you have an awning over your balcony? Will it shade them in the winter?
concerning different size panels, all parallel SERIES STRINGS on the MPPT need to have approximately the same Vmp, e.g., your 54.7Vmp panel could be in parallel with 3S 100W panels. 100W panels tend to be around 18Vmp, so 3*18V = 54V. If you have 2S of the 327W panels, you'll need 6S 100W panels to match their Vmp.
Yes they are. I have a 250/100, and it hurt.
Per the above, you would have to match the series Vmp, and 2X of the 250W wouldn't cut it.
Agreed. this panel's Vmp is close to mine.
Yes. For option 4, 60A would suffice.
There are other MPPT besides Victron. Will lists several:
DIY Off Grid Solar Charge Controllers
Building a vehicle mounted solar power system? Let me help.
www.mobile-solarpower.com
A friend of mine has 2X Outback FlexMax FM80 controllers. Those are typically less than $500.
Your MPPT needs to be sized to the CHARGE current the array power can provide as you calculated in the above 4 options. You can opt to go below that, but you'll lose some peak power during middle of the day.
2S3P
Based on the above, the two smaller panels from Santan aren't compatible with the Sunpower.
26.2691812, -80.2454113 from google mapI understand the sketch is approximate, but this is what I see; all panels will fail to capture significant portions of the day's sun:
View attachment 75604
What is your latitude? Will you be able to tilt them to approximately that degree from horizontal?
Do you have an awning over your balcony? Will it shade them in the winter?
concerning different size panels, all parallel SERIES STRINGS on the MPPT need to have approximately the same Vmp, e.g., your 54.7Vmp panel could be in parallel with 3S 100W panels. 100W panels tend to be around 18Vmp, so 3*18V = 54V. If you have 2S of the 327W panels, you'll need 6S 100W panels to match their Vmp.
Yes they are. I have a 250/100, and it hurt.
Per the above, you would have to match the series Vmp, and 2X of the 250W wouldn't cut it.
Agreed. this panel's Vmp is close to mine.
Yes. For option 4, 60A would suffice.
There are other MPPT besides Victron. Will lists several:
DIY Off Grid Solar Charge Controllers
Building a vehicle mounted solar power system? Let me help.www.mobile-solarpower.com
A friend of mine has 2X Outback FlexMax FM80 controllers. Those are typically less than $500.
Your MPPT needs to be sized to the CHARGE current the array power can provide as you calculated in the above 4 options. You can opt to go below that, but you'll lose some peak power during middle of the day.
2S3P
Based on the above, the two smaller panels from Santan aren't compatible with the Sunpower.
no awning
the panels will be tilted and in a angle ofcourse to face the sun as much as possible
I will have to build a stand
in the summer the sun will be higher how do i know if its going to hit the panels i assume so it is will be more dificult to tilt it enough let me include some more pictures..
so the 4 327W and the 2 250W would not work together right?
Can I have 5 panels of the same 327W i rather have bigger panels...
end of the balcony
so the logical thing to do is to get the same size panels instead of matching them so all 6 either 250W or 327W or just get 4 of each size right?
regarding the last part of my post i was just comparing the amazon prices to santan ... santan still comes out less
I find this : http://www.fsec.ucf.edu/en/publications/pdf/fsec-dn-4-83.pdf
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sunshine_eggo
Happy Breffast!
I would call that "roof" over the balcony equivalent to an awning.
Are you aware that these 327W panels are over 5' tall about 3.5' wide? Your balcony looks very small. The railing will cast a shadow on the panels and destroy their output to a tiny fraction of their potential.
Earth's axis tilt is about 23.5°. That means that during summer, the sun is nearly directly overhead, and the roof over the balcony keep it nearly completely in shade.
I suggest you completely re-evaluate this project purely from the standpoint of available space and solar positioning. I doubt you can hope to produce even a small fraction of the scale we've discussed so far.
