Solar Panels End-to-End? AND - Why are the Ends Sealed?

[beartoothweb]

Just a quick question. I have 10 panels I need to install. I have plenty of room, more or less, but I was looking at how wide these things are when all laid out side by side. With the connectors, it's like 26'+ wide.

I was thinking that if I split them, and did 2 rows of 5, and connected them that way, I could save some space/width.

I'm really thinking about doing 2 sets of 5 panels that are parallel. Each of the sets are in series, but not all 10. Is there any reason NOT to do this? Is there an efficiency gain of series vs. parallel? Theoretically, I can run them all in series, it'll just take a bit more plumbing.

ALSO ---can someone tell me what the purpose is for the ends of each panel to be sealed, rather than connected together like the tops? Is that for air release, or for some other reason?

 

[lbridges]

There is no reason why they can't be set up as two parallel arrays of 5 panels each with the 5 panel sets in series.

You lost me on the end of each panel sealed. The input side of the 5 panels should connected together serially with only the far side closed/capped. The output side is the same.

This site has an online installation manual that shows how multiple units can be plumbed up. You should be able to find similar manuals for other brands if this isn't clear enough.

Here's a pic showing two sets of panels - each set in series the two sets in parallel.

 

[Melt In The Sun]

I could be crazy, but aren't panels all supposed to be plumbed in parallel?

 

[beartoothweb]

Thanks!

The end caps are on the sungrabber panels. The top 2 in/out of the panel are plumbed in, then out to the next panel or pool, the bottom has 2 "outs" but each are capped, rather than plumbed like the tops (ie: in on one to out on other, etc.) This is how they came for parts.

This is how they are plumbed right now. I'll probably plumb them like the 4.2 figure, although I'm not sure why they carried the bottom connection all the up (on the left side) instead of just coming straight into a T). It looks like that I should be plumbing the bottoms together as well.

 

[Bama Rambler]

The sungrabber panels are marketed as above ground units and therefore have a "diverter" molded into the header. There is no way to remove the diverter and plumb the panels parallel. The way you have to plumb them is in series and that wouldn't be a real problem for a couple of panels but for ten, it's going to severely affect the performance.

If you haven't bought the panels you want to get the units for inground pools. If you have bought them see if you can return them.

 

[beartoothweb]

The sungrabber panels are marketed as above ground units and therefore have a "diverter" molded into the header. There is no way to remove the diverter and plumb the panels parallel. The way you have to plumb them is in series and that wouldn't be a real problem for a couple of panels but for ten, it's going to severely affect the performance.

If you haven't bought the panels you want to get the units for inground pools. If you have bought them see if you can return them.

Interesting. I actually have 8 sungrabbers, 4 of which I bought several years ago, and 4 that I got for like $50 on craigslist. Then I have 2 new Fafco type units.

I'm not sure I understand the "molded diverter." These units essentially have a 1" tube on top and bottom, and then the small tubes all connecting them on both ends. You can actually hook up either end, and the water will flow through, as near as I can tell. Even if you open both of the ends, water will flow out of both. They also sell diverters for these specifically.

Sorry, I'm being dense, can you pontificate more on the performance issue, etc? If it's a matter of how they are plumbed, I'm starting from scratch, so I can do whatever I need to.

 

[beartoothweb]

Okay, so I took a closer look at one of the panels (i have a couple that need repair), and I do see the flow disc (found a reference too it by search) in the large tube. Someone posted that they removed that so they could run them all in parallel. You're saying you can't do this?

 

[lbridges]

...although I'm not sure why they carried the bottom connection all the up (on the left side) instead of just coming straight into a T)...[/img]

They do that so the height of the water rise is the same for all panels (output of bottom goes up to output on top - both get in flow from height of bottom). The illustration should consider these on a roof with the top of the drawing higher in elevation (if that wasn't clear). Otherwise the lower panels would get more flow and the heating would be unbalanced and less effective.

 

[Bama Rambler]

The ones I saw had the disc molded in and there would be no easy to remove it without drilling or hole sawing. I think the danger would be in the possibility of drilling through the side wall trying to remove it.

If it's easily removed then by all means do so.

 

[beartoothweb]

The ones I saw had the disc molded in and there would be no easy to remove it without drilling or hole sawing. I think the danger would be in the possibility of drilling through the side wall trying to remove it.

If it's easily removed then by all means do so.

I have a pretty banged up panel that I can try it on. 3/4" - 1" piece of pvc and a hammer should do it. I'll report back...

 

[NWMNMom]

our Solar Bear panels are built with an adjustable diverter in the header and we do in fact have them plumbed in parallel - you simply flip one face down so that the IN flow is on the bottom for both

 

[arvil]

Happened to find this while browsing the site. As a driver/volunteer firefighter, I thought of this in terms of friction loss of the water in series or in parallel. Think of it this way. Let's assume the pump output is something like 40 gpm, hook the panels in series, now the water has a very long way to go. The friction loss will cause quite a decrease in flow rate. Putting them all in parallel, the pump will now flow at it's full capacity. 40 gpm ÷ 10 panels = 4 gpm each panel. At 4 gpm per panel, the water will spend a long time in the panel and should get much warmer before returning. Imagine putting ten straws together and trying to blow through them, then put the ten in your mouth at once, which way do you get more flow? Sorta like series and parallel resistance circuits. I would opt for parallel any day.

 

[beartoothweb]

Just a follow up to this. I had originally installed these into my main pump system as is, and the flow was terrible. I probably lost 60% at least from the diverters. But, with a little time, a concrete stake and hammer, all of the diverters are now out, and flow is restored. I need to do repairs on 2 of the panels and get them hooked up, but even with 1" headers, the sungrabber type seem to work well, and without any real head loss. I'm running the pump about 40' from the pool, then the panels another 50' or more from the pumps, so the water is going a long way.

Once all is said and done, I'll have them plumbed just like the 4.2 schematic above.

So, for those of you with the sungrabber panels, they will still function without the diverter. A piece of 3/4" pvc will also make a pretty good knockout tool, but be careful, I managed to get one stuck as the header was smaller on one.