24 volt solar panel recommendations?

pianotuna wrote:
Hi,

It is the experience of folks on the forums that poly panels do some what better in shade or partial shade.

No scientific research that I have found backs that up. The better shade performance is likely to do quality panels vs inferior panels, the poly being higher quality than the mono they are compared against.

I see it is rated for 30a at 12v and 22a with 24v, but am confused by this warning-

"....Do not connect a PV array capable of delivering greater than 24 amps of short circuit current ISC at STC with 36 cell modules, or 11.8 amps with 60 cell modules....."

http://www.blueskyenergyinc.com/uploads/pdf/Manual_BSE_SB3000i.pdf

Hi,

I see 17 amps of output (mppt controller) from 256 watts of panels with a flat fixed install. Input voltage is 33.

JiminDenver wrote:
My pair of 245w panels peaked out at 34a and that was at 10,000 ft and tracking the sun on a cold morning. I don't think he will see much clipping in a flat mount.

Hi,

It is the experience of folks on the forums that poly panels do some what better in shade or partial shade.

The extra efficiency of mono only allows a slightly smaller panel. If a poly panel fits--then the end result is the same number of watts.

Jfet wrote:

pianotuna wrote:
Hi tpi,

I believe solar panels work, or they don't. So long as there is an ability to exchange a non working panel I'd go on best price.

I would want as many diodes per panel as possible, and I'd probably favor Poly over Mono.

Why?

"Monocrystalline cells have a higher efficiency than polycrystalline cells due to the structure being made from one large crystal as opposed to many small ones. In addition to having an overall better efficiency, monocrystalline panels can perform up to 10% better than polycrystalline panels in high ambient temperatures."

Thats his plan-if the controller is maxxed out too frequently he'll upgrade. Westend thanks didn't realize that was input. Thought it was output..

tpi wrote:
Westend, what you're saying is it is essentially OK to let the controller limit the output to the 22 amps? There was nothing in the documentation that sounded too dire if you were to exceed the recommended input.

Edited my above post. The 22 amp current limit is INPUT. As 2oldman said, a bigger controller won't be tossing away charge current but I'd doubt there will be much to toss with two modules.

tpi wrote:
There was nothing in the documentation that sounded too dire if you were to exceed the recommended input.

It'll probably just get hot.

I would hope an upgraded controller is in the future should that be the situation. That's lost power.

Westend, what you're saying is it is essentially OK to let the controller limit the output to the 22 amps? There was nothing in the documentation that sounded too dire if you were to exceed the recommended input.

tpi wrote:
https://www.solarblvd.com/index.php?cPath=1_270

Is there any on this list notable for high quality?

I don't think he cares about spending a few more bucks if it reliably translates to quality.

I've heard good things about the Canadian Solar modules. They are built for the North so have good durability.

In a previous post you said that the user is going to switch one module so that the controller won't be affected by a large current. I'd suggest that he wire both in parallel and switch the single power lead before the controller. I'm not familiar with Blue Sky controllers but most MPPT controllers clip the input at whatever the rating is and continue to push the rated current to the batteries. There would be little reason to halve the available harvest to get under the controller's rating.

Edit: Did a little reading about the Blue Sky controller. It is limited by 22 amps of INPUT from 24V modules. It's going to be difficult to get two modules with a short circuit current rating of 8 amps to deliver 22 amps.

I'll study more.. I'm sure I can upgrade when I go to pick them up.