Solar Panel over roof ridge

Feb 25, 2015
100
Davis, CA
Hello,

I am trying to plan for my solar placement. Just a little background of how my pool and equipment pad are placed. The pool is on the south west side of the house. The equipment pad is on the east side of the house. I have three sections of roof I can put it on. Each roof is labeled as 1, 2 or 3 (see diagram below) with the following information:

Roof 1: East facing. Have approximately 23W x11H space to put solar panels. Please note that in the picture, there are trees that shade this roof. The tree has been removed so it gets full sun right now. If I use this roof, I can get five 4'x10' panel for a total of 200 Sq Ft.
Roof 2: West facing. Have approximately 18W x 16H space to put solar panels. I can put four 4'x12' panel for a total of 192 sq ft.
Roof 3: South facing. Have approvimately 16W x11h space to put solar panels. I can put four 4'x10' panel for a total of 160sq ft.

If I go with the south or west facing roof, I need to run the pipe from the equipment up the east wall, over the ridge and then to the solar panels. According to the diagram I found below, they suggest that I instll a 1/2" PVC pipe from the low point of the system and tie it back to the feed pipe.

Question: Is the 1/2" PVC pipe really needed? Wouldn't the main feedline automatically drain the solar panel by siphoning?

Where would you put the solar panel?

BTW - I live in northern California near Sacramento, so we get a decent amount of sun with little freezing,



 
Depending on how much heat you need, I would put panels on 2 and 3. But, if you only want to pick one then south facing is always the best choice. Yes, you need the 1/2" drain line to to drain down, not only for freeze protection, but it also best for the panels to drain down when not in use. Solar valves have a pinhole that allows the solar panels to drain down every time the valve closes.

I don't know if you have pool automation or what kind of equipment you have but, the best thing I ever did for my solar panel efficiency was to add the Solartouch solar controller. It has a sensor on the roof and sensor in the water line and only turns on solar when solar heat is available. The Hayward GL-235 is also a popular solar controller.

There are pics of my solar panels and plumbing in my build thread link in my sig if you want to look at solar installs.
 
Thanks Pooldv. I do have automation set up (and prepared) for the panels. It's a matter of buying the panel and installing it. I don't know how much of a temperature increase I want. During the summer, my pool can get warm - but I wouldn't mind a warmer pool. :) When you say that the solar valve has a pin hole, is that on the three way valve on the feed side? Right now - I have a Jandy 3-way NeverLube valve already installed. It did not have a pin hole in it. If I have to, I can always take it apart and drill a hole to allow drainage.

Just out of curiosity - why does panel need to drain down when not in use? Is it to prevent the extra weight (thus wear and tear) on the panel when it's not in use?
 
My previous house had to go up and over .. installed by Heliocol, no small line to let them drain (first i have heard of this). I just had a low point valve I could open in the winter to ensure the panels were empty.

If they are left with water in them, they can get very hot and soften the plastic and maybe cause problems.

The Pentail solar valve has a check valve in the 3-way diverter. But with your existing 3-way, you could just drill a small hole in the diverter.
 
I'm a big fan of warm pool water! 85 and up for me.

Yes, solar panels are drained down to avoid the weight, overheating of water that could damage the panels and the potential vacuum in the plumbing from the weight of the water.
 
Just a follow up. So should I go with the 1/2 PVC drain line as shown in the picture above or will it be fine to not install it? If I don't install the drain line, I will takes Jason's advice and install a small "low point valve" so that i can drain it during the winter. I personally prefer not to have to install 1/2 PVC drain line if i don't have to.

I am really curious to hear from others who have installed solar panels that go over the ridge.


Thanks
 
Diverminth

I have Fafco panels installed on both sides of my ridge in Gold River just east of Sacramento. Installed by Sierra Pacific. They work fine even over the second story. Sometimes too fine. The best part of the drain line -- is that to drain you open the faucets at the pad and at the drain and they drain-- I would run the drain to the ground and drain from there. If you want to see what I have send me a PM.
 
gwegan - I'd love to see pictures of your setup. I am going to install the solar this weekend. So you actually have a drain line shown the diagram above and not just a low point valve on the roof?

It just that if i install the drain line, it will be viewable from the backyard. I guess I can run the drainline through the attic to the other side of the house.
 
My drain line runs down the outside wall and is painted to match the house -- looks like another downspout. It is in the vegetable garden side of my yard.
drain capture Capture.jpg

In the picture above the drain is to the lower right so the lower set of panels on the other side of the ridge can drain. My equipment pad is at the opposite corner of the house. The whole thing is below.

drain capture 2Capture.jpg
 

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Thanks again for the quick response.

In the diagram that i have in the original post, the drain line is tied back into the feed line. If I am correct, it looks like your drain line does not tie into the feedline. It sounds like your drain line has a spigot/valve at the end (close to the ground) so you can easily drain it. Is that correct?
 
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