Any recommendation for buying Solar Panels in US.

[Hedges]

I request shipping to a nearby freight terminal, where I go with my pickup for "last mile" delivery.
A good stack of PV panels was about 1200 lbs. I was told only one would fit in a full-size pickup, but I DIY'd a longer bed and carried two pallets at a time.

Mine is a "3/4 ton" pickup, a K2500 HD. It carries 2500 lbs.
A "one ton" is good for about 4000 lbs.
I used to have a "2 1/2 ton" F600. Originally a box truck, it had a dump bed instead. 20,000 lb GVWR, 9000 lbs empty, could carry 11,000 lbs of gravel.

 

[Stewfish]

@Ampster thank for pointing out CED Greentech, who's Web site provides an incredible choice of PVs.
I contacted the San Francisco Bay Area location and I had a very good talk over the phone.

However, when I went there they were not able to find any 72 cells.
They only carry 60 cells, and mostly the Hanwha Q-Cells type,
and mentioned that the 72 cells were used for industrial applications.

They also mentioned that they would not sell to me any electrical hardware devices,​

telling me that those were very complex (meaning risky..) to use and they could not provide any help.​

But instead, I could get from them any mounting hardware that I might need.​

In particular they recommended to use the IrondRidge website which provides a tool to design solar installations.​

This tool indeed allows you to determine the hardware needed to design your roof or ground mounted solar system,​

using ASCE 7-16 (American Society of Civil Engineers) wind design code or recommendations​

and ATC (Applied Technology Council) hazards information.​

While everything looks so simple as an armchair developer,
I realize that becoming a hobbyist solar installer is more challenging than expected.

I contacted some PV distributors but in general they sell palettes stack of PVs​

weighing above 3,000 lbs, more than a one-ton pickup truck could carry.​

​

Beside shipping cost (that I found similar to shipping a car by truck...),​

I have also issues with shipping company no willing that​

a semi truck double park in order to deliver in residential area.​

I am feeling now going back to square one.
I have some space constraints so I would prefer getting efficient new PVs, even if I need buying a full stack.
I would be interested reading about any recommendation or previous experiences from getting PVs.

Santan solar was the best prices, best shipping price and packaging, will send 25 or less per pallet. I got 10 once. And on holidays their used solar farm panels are $35. I would only buy from them, not one panel was cracked on two pallets even after driving down my gravel road.

 

[再生可能 エネルギー]

Santan solar was the best prices, best shipping price and packaging, will send 25 or less per pallet. I got 10 once. And on holidays their used solar farm panels are $35. I would only buy from them, not one panel was cracked on two pallets even after driving down my gravel road.

I agree that they have some large panels in the range of $0.35 to $0.45/W that would perfect for my usage.

Now finding a good MPPT would be my next challenge.
I was looking at a large 156 Cells, with Voc = 52V and Imp 11A.

I have 3 strings (East, West, Flat) of 6 PVs, and I will consider that only two strings would be producing in the best case.

- In the case of a 2P-3S string, I would get a Max voltage of 156V and Max current of 22A, and 44A for two strings.
- In the case of a 3P-2S string, I would get a Max voltage of 104V and Max current of 33A, and 66A for two strings.
There will be more than 100 ft from the connection box, I might have to use two set of wires.

With each string producing about 3,500W, under 50V it will be around 70A for one string and 130A for two strings.

I would be interested finding an MPPT working with those large panels (more than 150V input, and 100A output).
I am considering to keep the inverter separate, as I only need a 48V 1kw inverter since my project use only LED lights.

 

[Hedges]

If you have 3 orientations, you want 3 strings. Connecting 3s2p would mean PV panels of different orientations connected in series, which reduces power output.
If 2 panels East, 2 panels West, 2 panels Flat, you want 2s3p. Highest power harvesting is 3 MPPT, one per orientation. But that is reportedly only 2% better than connecting all in parallel (assuming no shading.)
Connected in parallel at the array, a single pair of wires back to SCC is better utilized because strings take turns sending their peak current through wires.

So you would like an SCC of at least 145Voc and about 146A output (into 48V)

Here's one that exceeds those figures:

Is it morally wrong to marry your SCC? Victron MPPT RS 450/200

WOWZA.... I think I just met my future life partner...... I ordered this for the following project ( https://diysolarforum.com/threads/bi-facials-installation-height-matters-just-as-much-as-the-angle-of-the-dangle.22325/page-2#post-294377 ) as I wanted high VDC and the fact it had 2... AH AH...

diysolarforum.com

A bit smaller, 120A:

GROWATT 120A MPPT 250V Charge Controller

This is a listing for: (1) Growatt 120A / 250V SC48120 charge controllerThis advanced PV charger with microprocessor control for professional use. The charge controller is equipped with LCD display and front panel for easy and accurate settings. *Please note, the application is available on both...

shop.signaturesolar.us

- In the case of a 2P-3S string, I would get a Max voltage of 156V and Max current of 22A, and 44A for two strings.
- In the case of a 3P-2S string, I would get a Max voltage of 104V and Max current of 33A, and 66A for two strings.

I think you're mixing something up here.
Each string will have current Imp or Isc of a single panel.

Don't connect single panels in parallel, then groups in series. Connect single panels in series to make strings, then optionally connect strings in parallel.
Three separate MPPT SCC is also a reasonable way to go. Each should be about 80A; many brands/models to choose from. If one fails, you still have the others. If SCC is tolerant of over-paneling, you could then put East || West into one SCC and Flat into one SCC, for less reduction in power output.
Having separate wire pairs for each string give you flexibility to reconfigure later. Calculate what percentage voltage drop you'll see. I use 12 awg per string, but your Vmp is much lower so you may prefer thicker wire.

 

[NwCali]

I went with Signature Solar, and I am in North West California.

 

[caki]

I like to recommend kinectsolar.com . They specialize in liquidating stock, so you can find some great deals there. Here is their spreadsheet:

Kinect Solar - Inventory MASTER

REDIRECT NOTICE Check out our new, improved inventory search page. Kinect Solar’s equipment listings can now be found on our website by clicking the link below. That’s right - no more clunky spreadsheets 👏. Please note, after January 1, 2024, you will need to log into your Kinect Solar acco...

docs.google.com

 

[Stewfish]

I agree that they have some large panels in the range of $0.35 to $0.45/W that would perfect for my usage.

Now finding a good MPPT would be my next challenge.
I was looking at a large 156 Cells, with Voc = 52V and Imp 11A.

I have 3 strings (East, West, Flat) of 6 PVs, and I will consider that only two strings would be producing in the best case.

- In the case of a 2P-3S string, I would get a Max voltage of 156V and Max current of 22A, and 44A for two strings.
- In the case of a 3P-2S string, I would get a Max voltage of 104V and Max current of 33A, and 66A for two strings.
There will be more than 100 ft from the connection box, I might have to use two set of wires.

With each string producing about 3,500W, under 50V it will be around 70A for one string and 130A for two strings.

I would be interested finding an MPPT working with those large panels (more than 150V input, and 100A output).
I am considering to keep the inverter separate, as I only need a 48V 1kw inverter since my project use only LED lights.

I like my two MPPT LV6548. I got them straight from the factory from peggy. The money you save is enough to ship it back if you ever have warranty issues and it took 3 days to arrive vs months on a boat through other sellers.

She answered all my questions and helped setup the wifi app bc it was not working.

For the app to configure the first time you have to turn off cells er ice/data so it uses the wifi only as it connects to the MPPT wifi then back to your personal wifi and not try LTE before connecting to your wifi. Its like setting up a chromecast.

You can monitor away from home, adjust setting away from home, etc.

The LV6548 does US split phase 240v if you connect 2 of them, otherwise it's normal 120v with just one.

Good price, 6000w, can take in 250v DC 18a per input, lots of good stuff. Also it can take in generator power if your battery is low and its cloudy.

The batrium K9 is a solid BMS and a good price for a lifetime quality BMS

 

[再生可能 エネルギー]

I like my two MPPT LV6548. I got them straight from the factory from peggy. The money you save is enough to ship it back if you ever have warranty issues and it took 3 days to arrive vs months on a boat through other sellers.

She answered all my questions and helped setup the wifi app bc it was not working.

For the app to configure the first time you have to turn off cells er ice/data so it uses the wifi only as it connects to the MPPT wifi then back to your personal wifi and not try LTE before connecting to your wifi. Its like setting up a chromecast.

You can monitor away from home, adjust setting away from home, etc.

The LV6548 does US split phase 240v if you connect 2 of them, otherwise it's normal 120v with just one.

Good price, 6000w, can take in 250v DC 18a per input, lots of good stuff. Also it can take in generator power if your battery is low and its cloudy.

The batrium K9 is a solid BMS and a good price for a lifetime quality BMS

Can you provide peggy link?`

 

[Stewfish]

Can you provide peggy link?`

They have been using MPP in Australia for a decade with 10 year old+ units still going strong.

Direct alibaba store: https://app.alibaba.com/dynamiclink...share_detail&ck=share_detail&shareScene=buyer

Her email - peggy@mppsolar.com

I messaged her originally from the store link about the product and confirmed it was correct for the US, etc to make sure I didn't miss anything. She will put together a quote that has the shipping costs to your place.

 

[再生可能 エネルギー]

Three separate MPPT SCC is also a reasonable way to go. Each should be about 80A; many brands/models to choose from. If one fails, you still have the others. If SCC is tolerant of over-paneling, you could then put East || West into one SCC and Flat into one SCC, for less reduction in power output.
Having separate wire pairs for each string give you flexibility to reconfigure later. Calculate what percentage voltage drop you'll see. I use 12 awg per string, but your Vmp is much lower so you may prefer thicker wire.

Since I don't have any shadding issues, my intention is to have 3 panels in serie (Voc = 52V Imp 11A), so each string (3S) will be 156V and 11A.

Having (option 1) 3 separate MPPTs, and each having 2 strings in parallel (156V and 22A) would be the optimum (3 x 3S-2P),
but the East and the West would never produce solar energy at the same time,
so I guess they could be connected together in parallel (3S-4P) without losses?

Otherwise (option 2) having 2 separates branches with each having one East, one West, and one Flat string (2 x 3S-3P),
would provide similar results as (option 3) having one branch with two East and two West strings in parallel (3S-4P),
and another branch with two Flat strings in parallel (3S-2P).

Looking at the 3 wiring options, it seems that the option 2 (2 x 3S-3P) has the advantage of spreading each string peak solar energy
in two separate branches, especialy for the flat panels. This would reduce peak current resulting in lower wiring losses.
The option 2 (2 x 3S-3P) would also makes the junction box wiring symetrical and simpler than (3S-2P + 3S-4P).

With 100 ft of wires, each (3S-3P) branch (156V and 22A), using AWG 8 will get 1.6% (2.5V drop) and AWG 10 will get 2.6% (4V drop).
For each (3S) string (156V and 11A), and 30 ft for the longest ones, using AWG 10 will get 0.4% (0.7V drop) and AWG 12 will get 0.7% (1V drop).
I imagine that using AWG 10 for each string would be fine, I doubt I could use AWG 8 with MC4 connectors anyway.

I am now considedring using a Sigineer Power MPPT48120 SSC which has 2 separate MPPT input (VoC max 250V)
but I am open to getting recommendation to any other combinations than 2 x 3S-3P and SSC,
especially if I plan getting additional panels and SSC to harvest surplus for water heating.

 

[Stewfish]

Since I don't have any shadding issues, my intention is to have 3 panels in serie (Voc = 52V Imp 11A), so each string (3S) will be 156V and 11A.

Having (option 1) 3 separate MPPTs, and each having 2 strings in parallel (156V and 22A) would be the optimum (3 x 3S-2P),
but the East and the West would never produce solar energy at the same time,
so I guess they could be connected together in parallel (3S-4P) without losses?

Otherwise (option 2) having 2 separates branches with each having one East, one West, and one Flat string (2 x 3S-3P),
would provide similar results as (option 3) having one branch with two East and two West strings in parallel (3S-4P),
and another branch with two Flat strings in parallel (3S-2P).

Looking at the 3 wiring options, it seems that the option 2 (2 x 3S-3P) has the advantage of spreading each string peak solar energy
in two separate branches, especialy for the flat panels. This would reduce peak current resulting in lower wiring losses.
The option 2 (2 x 3S-3P) would also makes the junction box wiring symetrical and simpler than (3S-2P + 3S-4P).

With 100 ft of wires, each (3S-3P) branch (156V and 22A), using AWG 8 will get 1.6% (2.5V drop) and AWG 10 will get 2.6% (4V drop).
For each (3S) string (156V and 11A), and 30 ft for the longest ones, using AWG 10 will get 0.4% (0.7V drop) and AWG 12 will get 0.7% (1V drop).
I imagine that using AWG 10 for each string would be fine, I doubt I could use AWG 8 with MC4 connectors anyway.

I am now considedring using a Sigineer Power MPPT48120 SSC which has 2 separate MPPT input (VoC max 250V)
but I am open to getting recommendation to any other combinations than 2 x 3S-3P and SSC,
especially if I plan getting additional panels and SSC to harvest surplus for water heating.

Make it easy, get connectors from satan solar and their 10g wire bc 10g is what the connectors were designed for. Their wire has nice insulation too

 

[Stewfish]

Make it easy, get connectors from satan solar and their 10g wire bc 10g is what the connectors were designed for. Their wire has nice insulation too

Run your strings into these
Miniature DC Circuit Breaker, 1pc 250V DC Breaker 2P Low Voltage 16A/32A/63A, Solar DC Circuit Breaker for Short Circuit Protection(63A) https://www.amazon.com/dp/B08BF8CGG...t_i_TT4XX2KTME92C3CTT299?_encoding=UTF8&psc=1

Then combine the strings to go into your controller/s based on their rating they can take in

You will need din rail

And a breaker box (this one took my 6 strings of 3s)
uxcell IP65 ABS Transparent Cover Power Distribution Protection Box for Circuit Breaker Indoor on the Wall 18 Way (365 x 195 x 110mm) https://www.amazon.com/dp/B07GSVB9R...t_i_K7QWY4C31NMTVCG68ERA?_encoding=UTF8&psc=1

I mounted a 2x4 on the wall and spaced another 4fr away and then mounted 3/4" plywood and ran all my wires in the 1.5" gap behind the board and popped the wire into boxes or out of the board near the controller/inverter/fuse inputs

The black boxes to the left of the DC breaker box are where I combined the strings to fit into one controller input

The disconnects are dc rated from home depot, just to disconnect for any reason/safety

 

[再生可能 エネルギー]

Run your strings into these
Miniature DC Circuit Breaker, 1pc 250V DC Breaker 2P Low Voltage 16A/32A/63A, Solar DC Circuit Breaker for Short Circuit Protection(63A) https://www.amazon.com/dp/B08BF8CGG...t_i_TT4XX2KTME92C3CTT299?_encoding=UTF8&psc=1

Then combine the strings to go into your controller/s based on their rating they can take in

You will need din rail

And a breaker box (this one took my 6 strings of 3s)
uxcell IP65 ABS Transparent Cover Power Distribution Protection Box for Circuit Breaker Indoor on the Wall 18 Way (365 x 195 x 110mm) https://www.amazon.com/dp/B07GSVB9R...t_i_K7QWY4C31NMTVCG68ERA?_encoding=UTF8&psc=1

I mounted a 2x4 on the wall and spaced another 4fr away and then mounted 3/4" plywood and ran all my wires in the 1.5" gap behind the board and popped the wire into boxes or out of the board near the controller/inverter/fuse inputs

The black boxes to the left of the DC breaker box are where I combined the strings to fit into one controller input

The disconnects are dc rated from home depot, just to disconnect for any reason/safety

Thank you for reviewing my posting and for the description of your system.

What are the VoC and ImP of your VPs, and how many panels in each string?

Also what inside the outdoor boxes?

 

[timselectric]

I also purchased my panels from SanTan solar. Great price and customer service. I couldn't be more satisfied.

 

[再生可能 エネルギー]

Run your strings into these
Miniature DC Circuit Breaker, 1pc 250V DC Breaker 2P Low Voltage 16A/32A/63A, Solar DC Circuit Breaker for Short Circuit Protection(63A) https://www.amazon.com/dp/B08BF8CGG...t_i_TT4XX2KTME92C3CTT299?_encoding=UTF8&psc=1

I noticed that combiner boxes generaly use Fuse for each string instead of a Circuit Breaker.

Is there any avantage to use one or the other?

Is it safer to use fuses, because to can get fuses in a larger variety of Amps?

From your breaker example in the case of a 12 A string,​

- a 16 A Circuit Breaker might be a little to small, and​

- a 32 A Circuit Breaker might be a little to big.​

 

[timselectric]

I always choose my fuse by the label on the panels.

 

[Ampster]

Is it safer to use fuses, because to can get fuses in a larger variety of Amps?

From your breaker example in the case of a 12 A string,

The over current protection device should be sized to protect the wire. It can always be smaller if the panel label suggests a smaller size but it should never be larger than the size to protect the wire.

 

[timselectric]

When it comes to dc solar string circuits.
I fuse according to the panel label, and oversize the wire by 50% minimum.

 

[Hedges]

I noticed that combiner boxes generaly use Fuse for each string instead of a Circuit Breaker.

Is there any avantage to use one or the other?

There are combiner boxes with "polarized" circuit breakers, but I believe those have a problem, won't properly interrupt fault current in the reverse direction if a string shorts.

I think non-polarized breakers should be used. Or, all polarized breakers ganged together, so if backfed one trips it shuts off the others.

A 2-pole switch or breaker to isolate both PV+ and PV- is useful, to work on system wiring safely.

 

[再生可能 エネルギー]

There are combiner boxes with "polarized" circuit breakers, but I believe those have a problem, won't properly interrupt fault current in the reverse direction if a string shorts.

I think non-polarized breakers should be used. Or, all polarized breakers ganged together, so if backfed one trips it shuts off the others.

I noticed this Watts247 "8-2 Solar Panel Combiner Box" with polorized cicuit breakers and diode protection, but not a cheap solution.