Going solar

[turf]

hey everyone!

im having a day so ima vent here right now.

my bus is pretty much finished, has everything ...plenty of electricity, but no solar. right now i got a bigass batteries and bigass gen and it does fine. on battery im good for a couple of days.

the gen will always be used for my big loads.... cooking and electric heat and ac.

i decided to put some panels on my bus to reduce the amount i run the gen.

so i read the forums here and am figuring it all out, i watch youtube videos and see the process. i picked out the stuff i want to use. looked up on the internet for suppliers and....

ok first.... roughly i wanted about 1500 watts of solar panels. i have room for 3 big panels on a rail system.... about 13' of my roof

i call supplier A. i say im a skoolie and want some panels on my rooftop. i tell him what i want. he says cool. but he thinks im better off with smaller panels mounted straight to the roof with z brackets. he lists both products on his website. i hemmed and hawed, and said i was looking for the rails. he apologized and sent me elswhere.

i call supplier B. tell him what i want and he says cool. here is our catalog and the stuff you want is in Denver available today. then i wrote back asking about another bit of hardware for the ysstem and he replied with..... i cant sell you this stuff, you should try supplier A.

ok back to supplier A. i call them up on the phone. say, hey remember me from yesterday? well the supplier B warehouse has the stuff i want, will you buy it and resell it to me? Supplier A says... let me check.

late friday night, i got an email from supplier A. we dont do business with supplier B anymore. would you llike z brackets?

so i respond back to supplier B. hey, A cant help me, can you? i have a wholesale license, i thought maybe his issue was retail.
um, he doesnt want to give advice. he is just a parts guys. yes he can sell me retail. he just didnt want to .

grrrrr

[nikitis]

This is why most of us fabricate our rail system.

3 large panels at most will give you 960 watts with today's technology. They are about 320 watts per panel for the most expensive ones. And they need to be mono crystalline, which is one silicate pour per square. Poly crystalline will be crumbled pieces of silicone pressed into one square and they aren't as good at absorbing the sun.

These are 5.4ft x 3.2ft in size.

I personally bought 6 Renogy panels at these wattage. So that's 3.2ft x 6 = 19.2 ft of my roof which will net me about 1920 watts if I put them short ways left to right. My bus is 30ft, but only like 24 ft of roof as 6ft is the dognose. Which leaves me 4 ft roughly for a couple of max air fans and that's it if I use them all.

The Supplier A guy you talked to doesn't understand your need. You don't want smaller panels because that puts smaller panels on at different angles. This means your solar system will suffer and only be as good as the weakest angled panel.

When you take a panel, and cover your hand over one of the smaller squares on a panel, they all come down to that one squares level. The same effect occurs when you have multiple panels but the sun isn't hitting one as well, all the panels come down to that worst panels input even if in good light. So you want your panels all the same angle.

The only exception to this rule is if you are separating the banks So if one side is a bank and the other side of your bus is another bank, then one bank won't affect the other, but in that scenario you still have one bank that's more absorbant than the other and you suffer a little loss compared to those who have the whole bank at the same exact angle.

It may look a little worse having panels like that not flush to your curved roof, but you'll get more juice that way.

To achieve what you want, 1500 watts, you'd need 5 of those panels at 320 watts, which nets you 1600, if you go with 4 you only get 1280 watts. With 5, you'd need 16 ft of roof and with 4, 12.8 ft of roof.

So those are your best options. And that's even assuming you have perfect sun, no blocking and at a good angle. and at the optimal times. You can push for 1500 watts, but most of the time a setup designed for that will only net you 1200 through the day unless conditions are perfect.

[desrtdog]

Assuming for that much power output you are looking at residential panels. I have 2 Q-cells 400w residential panels mounted across the front of the roof … they measure approx 1m x 2m


Mounted them together with extruded aluminum and attached them to pivots on the left side, with pins holding the right side down - can tilt them to catch more sun if desired…believe that they make larger output panels now -420w or more?

[turf]

i had a system like desrtdog in my head with 3 panels. staring at the front of the bus, i have room for 3 before the first AC unit.

supplier B sent me this and said this is what they have in their warehouse today.

Solar panels – Q.PEAK-DUO-BLK-ML-G10+410 (132-cell 410W)

https://www.rexelusa.com/p/2325849/q...-blk-ml-g10410

Mounting Rail – XR-1000-168A (14ft)

https://www.rexelusa.com/p/704372/ir...4/xr-1000-168a

Clamp - UFO-CL-01-B1

https://www.rexelusa.com/p/1274627/i...k/ufo-cl-01-b1

End Clamp – CAMO-01-M1

https://www.rexelusa.com/p/1275416/i...amp/camo-01-m1


and in my return email, i questioned the Camo clamp. the online info says the ufo part plus a barrel connector. no mention on the camo clamp.

thats when he said to go back to the first company. he doesnt give parts advice.

Monday, i hope to hear back from supplier B.

[Kentucky Dreaming]

Originally Posted by nikitis

Poly crystalline will be crumbled pieces of silicone pressed into one square and they aren't as good at absorbing the sun.

Panels are made of silicon. Sealant is made of silicone.

[Malevolence4845]

Panel brand and wattage aside, I've come up with a solution to have 8 panels total but not eat too much of my roof space. Two aluminum boxes with two panels on top, side by side running parallel with the roof. Inside the box two more panels on 500lbs 60" drawer slides. I'll space the boxes apart so I can have a roof fan in my room. (these are going on the rear to make the smallest cable run to my electrical cabinet) This whole box is getting riveted to my roof so I wont need special brackets. I can't angle my panels with this sadly. It's a little bit more on the fabrication side but maybe it's useful or at least interesting. Also your rant is understandable, that whole interaction sounds frustrating. Enjoy my crude diagram, If I make no sense I blame the lack of caffeine in my system currently

[turf]

i like that solution! but im just going to go with fixed panels.... i hope this meets my wattage needs.

i have considered in the past mounting some panels vertical on the sides of my bus.
i dont have any windows... so lots of real estate there. at first i thought i could mount some panels vertical, and then tilt them up like a canopy for my camp site.

after a while, i decided that 70" or so wasnt enough canopy, so why not just fasten them to the side.

but.... im not crazy... i think the 3 panels im planning now will fit my needs.

[Malevolence4845]

Originally Posted by turf

i like that solution! but im just going to go with fixed panels.... i hope this meets my wattage needs.

i have considered in the past mounting some panels vertical on the sides of my bus.
i dont have any windows... so lots of real estate there. at first i thought i could mount some panels vertical, and then tilt them up like a canopy for my camp site.

after a while, i decided that 70" or so wasnt enough canopy, so why not just fasten them to the side.

but.... im not crazy... i think the 3 panels im planning now will fit my needs.

I thought about the same thing with the canopy bit! Also thought panels would make great window awnings. But I found a 3 year old 20ft and 8ft manual awnings for $400 total and quickly jumped on that bargain.

I saw this when I first started looking at solar and mounting ideas. For three panels this might be a pretty fast and easy solution

https://www.youtube.com/watch?v=lvvBUhGPmKo

I'm sure this is something many understand but I'll say anyways. I always would use Grade 8 Bolts and hardware when mounting things that have the potential to take multiple directions of stress. Generator compartment, basement storage boxes etc etc. Stainless steel is strong but does sheer when the stress is right. okay PSA over.

Hopefully that may give you some ideas or someone else will post the ideal solution!

[turf]

Supplier B contacted me this morning and im hopeful to have my panels in the next d few days.

[nikitis]

Here's my idea.

I'm going to design it from scratch. I've yet to see anyone do this yet.

But the back two panels will be built on top of the deck, and will be on rail slides like a drawer, so when I'm parked it can go out and still charge, but reveals a deck underneath the wife and I can chill on to see the views at nascar. Or mountain views, or tent camp on top of.

When we're ready to get back on the road, we hop off, and slide them back in and lock'em. No wasted space, and get best of both worlds.

I claim copyright, but you may use this as long as you acknowledge the idea came from me.

[Malevolence4845]

Originally Posted by nikitis

Here's my idea.

I'm going to design it from scratch. I've yet to see anyone do this yet.

But the back two panels will be built on top of the deck, and will be on rail slides like a drawer, so when I'm parked it can go out and still charge, but reveals a deck underneath the wife and I can chill on to see the views at nascar. Or mountain views, or tent camp on top of.

When we're ready to get back on the road, we hop off, and slide them back in and lock'em. No wasted space, and get best of both worlds.

I claim copyright, but you may use this as long as you acknowledge the idea came from me.

Crap! I need to protect my idea as well Trademark added

[PorchDog]

CES CityEelectricSupply.com

They have branches in 30 states per their website. Free shipping on orders over 40 dollars !!!???

So-- they are an IronRidge Solar racking distributor. I went to the store, placed the order for two 14 foot iron ridge rails, and they shipped them to me for free.

I was very skeptical about the whole deal-- but it happened. And very competitive on the price for the rails.

[nikitis]

Originally Posted by PorchDog

CES CityEelectricSupply.com

They have branches in 30 states per their website. Free shipping on orders over 40 dollars !!!???

So-- they are an IronRidge Solar racking distributor. I went to the store, placed the order for two 14 foot iron ridge rails, and they shipped them to me for free.

I was very skeptical about the whole deal-- but it happened. And very competitive on the price for the rails.

Thanks for that. I actually have a CES near me in my city. I'll check them out.

[turf]

ooof

i didnt check the local electric supply place.

ok, now i checked. they dont carry ironridge.

phew



update from rexel... they have everything in stock except for the l bracket... checking to see if they can get it out of another warehouse.

[turf]

ok...
im ready for advice.

im picking out a solar charge controller. i'd like to have all victron in the end.

so by my panel calculations and going 24 volt.

for the amps
1230 watts solar / the charge voltage of 28.8 = 43A +20%safety =52A

for the input voltage..
45.3 is the panel VOC X3 = 135.9 + 20% safety = 163v

that specs out to the ......controller 250 60 a $400 + controller.

or
3 separate controllers.... 1 for each panel

that be a 100 20 controller.....or 3 of them, for about $90 each

or not quite spec is the 150 60 controller. if i understand... winter charging is high volts... but if im disconnected inthe winter....

idk

[desrtdog]

Your voltage call is correct if you plan on going there panels in series…if parallel, then panel currents are additive. (If you put panels in series any shade on one will effectively take down the whole array.)

As to the controller, I personally would opt for a single one…

[turf]

lolol thanks


im a bit confused so let me clarify.....

parallel would be the 3 controllers - cheaper, more reliable

series is the one big controller - more expensive but only a single unit.

you'd pick the series?

[desrtdog]

Originally Posted by turf

lolol thanks


im a bit confused so let me clarify.....

parallel would be the 3 controllers - cheaper, more reliable

series is the one big controller - more expensive but only a single unit.

you'd pick the series?

I might be misunderstanding what you’re asking…

What i’d recommend is that you connect the 3 panels in parallel and use a single charge controller. Doing this will give you an output from your panel array of say 45v, but will give a total output current of 3x the individual panel current - the higher current being the thing that will aid in charging your batteries

[nikitis]

Originally Posted by turf

lolol thanks


im a bit confused so let me clarify.....

parallel would be the 3 controllers - cheaper, more reliable

series is the one big controller - more expensive but only a single unit.

you'd pick the series?

You typically only need one charge controller and it handles the distribution from the solar panels to the batteries.

It would depend on the charge controllers input quantity.

If you have 6 panels and they are all in series, at 12V per panel, you will only supply 12V's to the Charge controller.

If you have 6 panels and 3 are in series, and 3 are in a different series, when you connect them at the Charge controller, it can combine them to be 24V's, because it treats the 3 in series as one panel, and the 3 in the other set a panel, and you are combining both in parallel to make 24V Array.

If you have 6 panels, and each one is in parallel, it would be 12V x 6 = 72 Volt system.

I think you said you were going for 24V system so do 12v x 3 panels, as one input, and 12v x 3 panels as the 2nd input into the charge controller. Which will give you 24v system.
In this scenario you want a charge controller that is 24V capable and can handle the amps. Your amps will be a little lower since you are going to 24V. A 12V system the Amps are higher. You can calculate your amperage rating on the back of your panel at 12V.

If you buy a 420 Watt panel at 12V, it's 420 divided by 12V = 35 Amps per panel. At 24V, amps cut down which is why you can use smaller wiring. 420 divided by 24V = 17.5 Amps. you add up the Amps per panel, so in your case if 3 panels = 35 Amps in 12V series, that's 105 Amps + 105 Amps from the other side. So you need a charge controller that can handle 105 amps per input.

What's also confusing is older systems used PV Combiners, but I think the Victron stuff does the combining for you today. Maybe someone can clarify.



For my example, I specced it out as a 24v system. 2 banks. Panels are 320 Watts. 40V peak, 33V operating. which brings to 10 or 9.50peak amps per panel.
So 320 divided by 33V = 10 Amps per panel. x3 = 30 amps roughly per bank. so 60 amps total which my chinese made charge controller can handle up to 60 Amps.

Mine is kind of weird cause the chinese charge controller states that it needs 32V's for a 24V battery system to deliver a higher V charge I guess. So my input from my PV array is 32V's 60 AMP total with both banks to charge the 24V battery system, and I have a 24 pure sign wave inverter for the AC outlets.

Pic has back of one of my panels

[jayb]

I went to a local solar panel installation company. They also replace damaged solar panels for insurance companies. Their back room had stacks of solar panels that had the electronic inverters had been taken out by a lightning strike, but the dc was still in tact. Now I have 4 294w solar panels on my bus that cost me a whopping $100 apiece. I have pics of them on my page.