100w panel discussion and my future system. Advice needed

[midwestsolarnoob]

Hi guys! I’m planning on ordering panels within the next month. Ive gone over several solar set up ideas on paper for the build. With this idea being the one that makes the most sense. I’m planning on my buying 16 100w panels. Basically I have the space to do 4 x 4 panels on a diy roof rack or roughly 160” x 80”. My mobile application is a Shuttle Bus we’re converting to a tiny home for traveling around the country. Roof is formed fiberglass which I’ve posted photos before. Reasoning for 100w panels is the generic 40” x 20” form factor. Almost all of them I’ve looked at are about that, give or take an inch. I’m also leaning towards the 100w panels for their smaller surface area per panel which should help with durability. And a 100w panel is a a lot cheaper to replace than a 400w. So my questions are as follows. And any advice is welcome as this will be my first solar build. I’m also leaning 24v for battery bank

1. What 100w panel brands are good enough for a mobile build? Renogy, Rich Solar, Eco worthy? Or any others brands worth mentioning?

2. Will I run into any problems with 16 panels?

3. Should I use 1, 2 or 4 charge controllers?

I guess my biggest concern is having problems on the road. I want to buy good panels but not over spend for a name.


Thanks for the help! I’ll definitely be looking for more help the farther into this build I get.

 

[mikefitz]

100w panel brands are good enough for a mobile build?

Renogy 200 watt half cell panels are a good compromise size wise for an RV,

200 Watt 12 Volt Monocrystalline Solar Panel

Limited time sale, 10% off: Renogy10off. The Renogy 200 Watt 12 Volt Monocrystalline Solar Panel is one of the main components for any solar power (PV) system

www.renogy.com

Half cell panels are more robust and may have advantage in shade conditions.

2. Will I run into any problems with 16 panels?

Just more connections to make.

3. Should I use 1, 2 or 4 charge controllers?

Two would offer a degree of redundancy. Consider the Victron Smart Solar controllers.
Two controllers, use the 150 35 unit . 100 watt panels arranged 4S2P , 200 watt panels 4S
A single controller, 150 70, 100 watt panels 4S4P , 200 watt panels 4S2P.
Need series panel fuses for 4S4P at the parallel junction

 

[midwestsolarnoob]

Renogy 200 watt half cell panels are a good compromise size wise for an RV,

200 Watt 12 Volt Monocrystalline Solar Panel

Limited time sale, 10% off: Renogy10off. The Renogy 200 Watt 12 Volt Monocrystalline Solar Panel is one of the main components for any solar power (PV) system

www.renogy.com

Unfortunately I lose out on wattage if I go with 200w panels. With the 100w panels I can fit 1600w (16 panels). 200w panels have too odd a size for me to fit 8. Or it’ll be like Tetris. Where the 100’s are a cut and dry 4 x 4 configuration. I’ve explored the idea of larger panels and can’t get them to fit with the same 1600w worth of paneling.

Thank you for the other advice!

What’s your advice on batteries? I’m in between DIY and EG4 solar racks. Are the cheap Chinese batteries worth the savings?

 

[42OhmsPA]

What’s your advice on batteries? I’m in between DIY and EG4 solar racks.

DIY or user serviceable, such as SOK, if you go pre-made. With user serviceable you can easily break down the pack for repairs, cell replacement, BMS replacement, etc.
Definitely DIY if you're looking at lots of capacity and want to save money.

Are the cheap Chinese batteries worth the savings?

Aren't they all Chinese batteries?

 

[Pi Curio]

For your consideration...


I'd imagine saving on weight should be beneficial on a vehicle.
A thing worth noticing is that 16x 100W solar panels will weigh about 15-20kg(33-44lbs) more than 4x 400W half-cut panels. That's probably more than the entire array mount rack weight.


The simpler the better.
Four 400W half-cut(with two halves, each half works independently of the other) solar panels would require less wiring and no additional parts such as fuses, etc.


Assuming this is for a 12V system...
I'd want to have at least two SCCs for redundancy and for having an overall better array design where I'd have 8 independent panel halves at my disposal to address the shading as much as technically possible while maintaining a higher array voltage and lower overall wiring part count.

Twin SCC 100/50 -2x400W in parallel combo, each for one side of the bus. Maybe a panel mount rack with two independent tiltable sides?

Interestingly enough, a single 200W half on a 400W half-cut panel has a smaller footprint than 2x100W in series(you want higher solar voltage for 12V).

In most cases, you can fit 4 x 400W panels within 160” x 80”(406 x 203cm), with a bit of space left in the middle to have access to all of the panels on the roof for wiring.

 

[Reed Cole]

I would strongly recommend considering ~400w panels. Probably should be able to find them locally and the cost will be much less than 16x100w panels.

 

[Pi Curio]

I would strongly recommend considering ~400w panels. Probably should be able to find them locally and the cost will be much less than 16x100w panels.

Excellent point!

Significantly cheaper! So much so, he could buy a spare 400W if he has the room for it, and still be way below the cost of 16x 100W panels.

 

[midwestsolarnoob]

For your consideration...


I'd imagine saving on weight should be beneficial on a vehicle.
A thing worth noticing is that 16x 100W solar panels will weigh about 15-20kg(33-44lbs) more than 4x 400W half-cut panels. That's probably more than the entire array mount rack weight.


The simpler the better.
Four 400W half-cut(with two halves, each half works independently of the other) solar panels would require less wiring and no additional parts such as fuses, etc.


Assuming this is for a 12V system...
I'd want to have at least two SCCs for redundancy and for having an overall better array design where I'd have 8 independent panel halves at my disposal to address the shading as much as technically possible while maintaining a higher array voltage and lower overall wiring part count.

Twin SCC 100/50 -2x400W in parallel combo, each for one side of the bus. Maybe a panel mount rack with two independent tiltable sides?

Interestingly enough, a single 200W half on a 400W half-cut panel has a smaller footprint than 2x100W in series(you want higher solar voltage for 12V).

In most cases, you can fit 4 x 400W panels within 160” x 80”(406 x 203cm), with a bit of space left in the middle to have access to all of the panels on the roof for wiring.

The biggest hurdle for me where I live here in the good ole Midwest, is our poor ability to adopt new things. That being said, not a lot of options for picking up residential panels.

My options are limited to a1solar having a warehouse 3+ hours away. They have 3 panel models available, starting at $327 a pop. And FB marketplace or Craigslist. I’ll keep looking!

I appreciate steering me towards 4 panels over 16. I get the simplicity of it. I can just get 16 100w panels for $1120 (still pricey)shipped for free.

I’ll have to keep an eye out for resale panels.

 

[midwestsolarnoob]

Actually, I just may found a seller 2 hours away! He’s selling 360W Silfab panels. All unused.

https://silfabsolar.com/wp-content/uploads/2021/09/Silfab-SLG-M-360-SF-0G-20191127-K-Final1.pdf

He wants $100 a panel or $80 a panel for the 7 available.

It would be a loss of 160w total. But I’m assuming that’s a good deal for new panels.

 

[midwestsolarnoob]

I would strongly recommend considering ~400w panels. Probably should be able to find them locally and the cost will be much less than 16x100w panels.

Excellent point!

Significantly cheaper! So much so, he could buy a spare 400W if he has the room for it, and still be way below the cost of 16x 100W panels.

Thanks for the info guys! It would make more sense to use 4 large panels over 16 small ones

 

[Pi Curio]

Nothing to it, happy to help.

 

[midwestsolarnoob]

http://www.crossroads-solar.com/uploads/1/2/7/3/127301517/380-395_panel.pdf

I found these panels being sold directly from the manufacture only a couple hours from me. They’re factory seconds but they said it’s due to cosmetic flaws. $155 a panel. With being seconds, they said 2 year product warranty and 5 year output. That’s obviously better than used panels with no warranty. What do you guys think?

 

[42OhmsPA]

http://www.crossroads-solar.com/uploads/1/2/7/3/127301517/380-395_panel.pdf

I found these panels being sold directly from the manufacture only a couple hours from me. They’re factory seconds but they said it’s due to cosmetic flaws. $155 a panel. With being seconds, they said 2 year product warranty and 5 year output. That’s obviously better than used panels with no warranty. What do you guys think?

I didn't open the link...
If they are 395W panels for $155 ea. that's not a good price at all, $0.392 / W is years ago pricing.

Did you check Inxeption flash sales or Santan Solar?

 

[HarryN]

Your brand list is good, maybe add solarland to the list.

There are three common places to buy solar panels on line that I think of:
- solar-electric.com
- Unbound solar
- alte

If you think that you will often be in diffused sunlight, then it is worth considering poly panels, but not the end of the world either way.

There is a natural tendency to want to buy the absolute max solar watt rating for a given size, but this can also lead to panels that require the light to be really perpendicular to the panel to work well.

 

[midwestsolarnoob]

Santan appear to all be older panels with less wattage for the same size as newer 400w panels. They have 10 panel minimum and it appears alot of places I’ve checked does. I need 5 max.

 

[midwestsolarnoob]

Your brand list is good, maybe add solarland to the list.

There are three common places to buy solar panels on line that I think of:
- solar-electric.com
- Unbound solar
- alte

If you think that you will often be in diffused sunlight, then it is worth considering poly panels, but not the end of the world either way.

There is a natural tendency to want to buy the absolute max solar watt rating for a given size, but this can also lead to panels that require the light to be really perpendicular to the panel to work well.

All three of the stores are more expensive than the panels posted. So I don’t think they’ll work for me.

I’ll have to look into the poly vs mono thing.

Thanks!

 

[Nevada Solar Designs]

lots of panel choices for an MPPT maintained battery bank.
the roof mount may be the biggest challenge with fewer quality solutions

 

[Pi Curio]

@midwestsolarnoob

Found one that fits size wise, is near 400W and is of a reputable brand. Has a bit high Voc.

Is the store below an option for your area? How much would it cost you to order 4-5 of these with delivery?

Used Jinko 395W Bifacial Solar Panel | SanTan Solar

The Jinko 395W Bifacial Solar Panel is one of the best-selling module. Get yours today! They do come with our 1-year SanTan Warranty.

www.santansolar.com

I tried searching for whats available near you in the US, but I havent found alot of options that are not overpriced, has low MOQ, or fits your requirements.


LE: If anything, maybe consider 10x of these if shipping is reasonable, and sell the extra 5 panels. Depending on the shipping cost, it might be close to 16x 100w panels cost-wise.

NE Solar 370W Mono Solar Panel (Black) | NESE 370MH-M6

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL

signaturesolar.com

 

[midwestsolarnoob]

lots of panel choices for an MPPT maintained battery bank.
the roof mount may be the biggest challenge with fewer quality solutions

Roof mount isn’t to difficult on our build. I have a few ideas for a diy one

 

[midwestsolarnoob]

@midwestsolarnoob

Found one that fits size wise, is near 400W and is of a reputable brand. Has a bit high Voc.

Is the store below an option for your area? How much would it cost you to order 4-5 of these with delivery?

Used Jinko 395W Bifacial Solar Panel | SanTan Solar

The Jinko 395W Bifacial Solar Panel is one of the best-selling module. Get yours today! They do come with our 1-year SanTan Warranty.

www.santansolar.com

I tried searching for whats available near you in the US, but I havent found alot of options that are not overpriced, has low MOQ, or fits your requirements.


LE: If anything, maybe consider 10x of these if shipping is reasonable, and sell the extra 5 panels. Depending on the shipping cost, it might be close to 16x 100w panels cost-wise.

NE Solar 370W Mono Solar Panel (Black) | NESE 370MH-M6

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL

signaturesolar.com

I forgot about signature solar! They have good deals. It’s only about $220 to ship 10 panels. Which isn’t bad when I can flip the rest for quite a profit in my area. Most the local resellers are charging premium price for used poly panels.

The only issue I’ve seen is when googling these panels it pulls up a thread on here where some folks are worried about the build quality. Possibly missing solders. I’ll have to do some more research