FWC solar question

[ottorogers]

The other thing to keep in mind is that ANY shade on ANY part of your solar panel will kill the output. So a tree shadow, or even a shadow from the roof vent, can really impact the output of the panel.

is this true with both stick-on and traditional solar panels? I thought this issue had been resolved with newer technology? I read somewhere that a newer design prevented this from happening with isolation of sections of cells???

 

[philos65]

https://www.batterypete.com/batteries/240-watt-solar-panel-rec-solar-rec240pe/

I did a lot of internet searching and found that this supplier had the least expensive panels. You have to buy four of them, but if you need only one or two, the price is so good you can easily get rid of them on craigslist. I sold two of my four in less than 24 hours.

http://blog.aurorasolar.com/shading-losses-for-pv-systems-and-techniques-to-mitigate-them/

Here's a good article on solar panels and shade.

 

[Vic Harder]

Those are wicked prices on panels. Good find!

The shade article isn't all that applicable to small installations, but the one point about bypass diodes is very applicable. IF your panel has multiple such diodes, it will be more tolerant of shade than others.

 

[ottorogers]

Those are wicked prices on panels. Good find!

The shade article isn't all that applicable to small installations, but the one point about bypass diodes is very applicable. IF your panel has multiple such diodes, it will be more tolerant of shade than others.

Vic do you know which flexible solar panel to buy? I really don’t want to make a mistake, I think 120 W is more than enough, with the compressor fridge, many people have said 100 W is enough, any advice would be greatly appreciated

 

[Vic Harder]

Vic do you know which flexible solar panel to buy? I really don’t want to make a mistake, I think 120 W is more than enough, with the compressor fridge, many people have said 100 W is enough, any advice would be greatly appreciated

Which? Lots of options. Does the amount of weight on the roof matter to you?

 

[cuervo]

Clever mounting technique!

Thanks; it's an Aurinco flexible panel glued to a sturdy aluminum plate and stainless fittings. It's been working well the last week or so with it hanging vertically. Right now I only get about 3 hours of usable solar what with the low angle of sun, the trees and the canyon sides. (on a sunny day...) Still it's keeping the system topped off, even on overcast days there's a bit of charge.

 

[ottorogers]

Which? Lots of options. Does the amount of weight on the roof matter to you?

yes the weight and height matters a lot

 

[Vic Harder]

Well, we know the heavy rigid panels work well, and are durable. Some folks have had good luck with the light flexible panels. Some folks not.

Assuming weight is worth the risk to you, then the biggest flexible panel(s) you can mount would be good.

Do you have the yakima tracks on the roof? Are you doing the work? Are you willing to make some kind of support for the flexible panels so they have a bit of space under them for ventilation? Or do you just want to stick on the flexible panels and take the chance they won't work well?

And about controllers...
If you have room for two 120W+ panels (12V) or one big 240W+ panel (24V) then I would recommend the Victron MPPT 75/30 controller to go with these, along with the monitoring gear. If just using one 12V panel, the Trimetric 2030 controller and monitor are excellent.

Oh, and where are you buying this stuff? Canada? USA?

 

[ottorogers]

Well, we know the heavy rigid panels work well, and are durable. Some folks have had good luck with the light flexible panels. Some folks not.

Assuming weight is worth the risk to you, then the biggest flexible panel(s) you can mount would be good.

Do you have the yakima tracks on the roof? Are you doing the work? Are you willing to make some kind of support for the flexible panels so they have a bit of space under them for ventilation? Or do you just want to stick on the flexible panels and take the chance they won't work well?

And about controllers...
If you have room for two 120W+ panels (12V) or one big 240W+ panel (24V) then I would recommend the Victron MPPT 75/30 controller to go with these, along with the monitoring gear. If just using one 12V panel, the Trimetric 2030 controller and monitor are excellent.

Oh, and where are you buying this stuff? Canada? USA?

we are going through Quartsite tomorrow

 

[ottorogers]

Well, we know the heavy rigid panels work well, and are durable. Some folks have had good luck with the light flexible panels. Some folks not.

Assuming weight is worth the risk to you, then the biggest flexible panel(s) you can mount would be good.

Do you have the yakima tracks on the roof? Are you doing the work? Are you willing to make some kind of support for the flexible panels so they have a bit of space under them for ventilation? Or do you just want to stick on the flexible panels and take the chance they won't work well?

And about controllers...
If you have room for two 120W+ panels (12V) or one big 240W+ panel (24V) then I would recommend the Victron MPPT 75/30 controller to go with these, along with the monitoring gear. If just using one 12V panel, the Trimetric 2030 controller and monitor are excellent.

Oh, and where are you buying this stuff? Canada? USA?

i have never seen any flexible panels over 120 Watts, I’ll check the company you mention, I’d rather have one 240 watt panel, stuck directly to the roof, low profile and easy install

 

[rando]

I have never seen a semi-flexibe panel over 120W either, I use two 120W solar cynergy semi-flexible panels in parallel to get 240W. And while I usually agree with Vic, I wouldn't recommend the Trimetric even if you are using '12V' panels. It is a case of paying more money for less - you can get a significantly more advanced MPPT charge for less money than the trimetric. You won't get a huge amount more efficiency from the MPPT, but particularly in the winter when your panels are cool you will see a noticeable increase in efficiency.

 

[Vic Harder]

I have never seen a semi-flexibe panel over 120W either, I use two 120W solar cynergy semi-flexible panels in parallel to get 240W. And while I usually agree with Vic, I wouldn't recommend the Trimetric even if you are using '12V' panels. It is a case of paying more money for less - you can get a significantly more advanced MPPT charge for less money than the trimetric. You won't get a huge amount more efficiency from the MPPT, but particularly in the winter when your panels are cool you will see a noticeable increase in efficiency.

Rando, you may think we are disagreeing, but I don't know that it we really are. Because I would go with the victron gear again, anyday. I just didn't want to sound to opinionated.

I would also go with a single big heavy panel again. Assuming that you have room for it on the roof. I think those rigs with two vents can't do that? So two smaller 180w range rigid (heavy) panels would be my choice in that case.

If you must have light, two or three flexible panels would likely do the trick... here is a recent review of the currently available flex panels
https://www.bestsolartech.com/best-flexible-solar-panels-reviewed/

 

[Vic Harder]

i have never seen any flexible panels over 120 Watts, I’ll check the company you mention, I’d rather have one 240 watt panel, stuck directly to the roof, low profile and easy install

240W panel assumed not-flexible... aka, heavy.

 

[ottorogers]

240V panel assumed not-flexible... aka, heavy.

way to heavy for my weight requirements