Interesting solar panel pic - see if you can spot it

[Diver]

This is a picture of my solar system. It's a bit grainy since it was taken late in a day, but there is something on it that is worth noting..

There is a line going across all the panels in the lower part. When I first saw it, I was somewhat puzzled. You can see it does not go parallel with the panel ties, but at the angle. That fact actually made me realize that it's a water level in the panels!

It just rained and got noticeably colder and the air was still very humid. There must be temperature difference of the surface of the panels between water and air field portions. Which resulted in different condensation amounts on the surface creating this effect. The pump was off at this point...

While pretty cool, I'm not too happy with water not draining completely. I think there are few factors that might contribute to that. The panels are basically water level and there is no much height drop. The vacuum breaker that I have seems to be pretty restrictive. There is Jandy check valve with a pretty strong flapper spring. The tubes in the panels are very thin, but probably still too big for any capillary action

I think come winterization time, I will need to blow the panels a tad to make sure they are empty..

 

[cowboycasey]

That is a really kewl solar system.. nice job

 

[Diver]

Thank you! It surprises me how well it works. It's about 48% or the pool surface area and until last Friday it was shaded probably at least 40% thru the day. Despite that, with solar cover on I got up to 95F! And that's in Boston area. We don't keep it at 95F, I just wanted to know how high it would go..

Some trees was aggressively pruned and now it's in the clear 10am to 3pm with some small patches of shade after that. It was a very cool project that took me about 9 months.

 

[Isaac-1]

Looks like a great design, I am curious to hear what you discover about the panels not draining. My first thought was back pressure from the return line allowing the check valve to close, that is if you are only switching valve position and not turn the pump motor off. My second thought was perhaps if you do have an undersized VRV then the check valve is closing at some point as there is not enough dynamic flow to keep it open.

Ike

 

[Diver]

Ike,

When pump is on and valve is switching from solar on to off, the panels do drain to some extent, because when the sun comes out again, there is air being purged from the panels.

I'm inclined to think it might be the vacuum breaker. I can't say that it's undersized since it was sold as designed for this system. I played with it for a bit and it seems like it does not allows for tons of air to come in. When the pump is off I can hear air hissing and it sounds like it's tight. It's this type:

I posted about it before.. I don't plan on doing anything about it. I don't think it hurts much anything. On closing the pool, I will open the dead end of the lower header to make sure it's fully drain. Maybe push some air thru with a compressor to be safe..