Solar Panel Install w/pcs Part 2 (dial-up beware)

All 44 panels assembled:

http://users.adelphia.net/~hudak/panelpilex.jpg

Once I got the panels up onto the roof, they were easy to put together. Put an o-ring on the male end, spread some lithium grease, insert a temporary assembly tool on the female end, push together, remove assembly tool and install permanent clip that holds the two together. Wham-bam.

Each top header is attached to the ridge beam of the roof using galvanized plumbers strapping and stainless steel screws and nuts.

Then all that is left is to run pvc pipe to the inlet end of the bottom headers, connect the outlets from both systems and then drop off of the roof with the two inlets and one combined outlet. Because of where the combined outlet is located, it was necessary to run the inlets pipes across each roof and then connect to the lower manifolds.

South roof set (the pool equipment is behind the fence on the left; the vacuum breaker for the whole system is on the lower left; the inlet for this set of panels is on the lower right and the outlet is on the upper left):

http://users.adelphia.net/~hudak/southroofx.jpg

West roof set (the inlet to this set is on the lower left and the outlet on the upper right; you can see the outlet where both panel sets combine by the chimney, which then drops off the roof to the equipment directly below; finally, there is a pressure gauge installed on the lower right):

http://users.adelphia.net/~hudak/westroofx.jpg

Here's a view of the outlet and the inlet going up to the west roof:

http://users.adelphia.net/~hudak/inandoutx.jpg

And where everything comes together. The outlet from the sand filter (lower right on the multi-valve) feeds through a check valve and then immediately tees to that black box which is the three-way valve that controls the flow to the solar panels. It is electronically-controlled; I have yet to hook-up the control panel and sensors. When the solar is on, the valve directs flow through the pipe that goes back towards the house and splits-off into two feeds that go to each panel set. Each feed has a ball valve so I can either isolate the set or meter the flow if necessary.

After the tee for the solar valve is a ball valve that meters the flow to the panels so as not to over-pressure them. So, some flow goes to the panels and some directly to the pool. The pressure gauge on the roof tells me whether or not there is too much flow. The outlet from the panels is the painted pipe on the far upper left; the flow goes through that clear check valve and then on to the pool.

http://users.adelphia.net/~hudak/equipmentx.jpg

I will wrap this posting up later in Part 3.

What are you building??? a Giant HOT TUB??????
That's a LOT of solar panels.....

What is the 6" pvc all over the garage for? Is it a dust collection system for the tools? I have the tools, just no dust collection system, besides a broom and shop vac that is.

Looks like a home brew Dust collector to me (nice job on it by the way)
Those wooden boxes look to be the shutoffs/seals on each access point.

LOL...yeah, it's definitely a lot of panels. But, what the hey, if you are going to install some, might as well install a bunch.

Seriously, though, since some of the system had to be on my west roof, more is necessary in order to achieve the main goal of extending the swim season when the sun isn't as intense.

Yes, the six inch pipe is for my dust collection system with homemade blast gates. The pipe system is connected to a 2 hp collector that collects all dust, small animals and your arm if one is not careful.

pj

pj - you are one of those "more power - arg arg arg" guys aren't you:D

How large is the pool? We are having a relatively small pool installed and we want to install solar but we can only install 360 sq feet on the west/north roof (so you don't see the panels from the street). Our pool is about 13,500 gallons (30X15).

More power is always good...don't need it all of the time, but it's there when I need it!

The critical measure is the surface area of the pool because that's where the heat is lost. My pool is 560 sq. ft.

You would be installing panels that are 80% of your pool, but putting them on the west roof (not great, but the next best place after the south) and the north (not good) will decrease their effectiveness.

Probably OK if all you are looking for is to heat your pool during the summer when the sun is high.

pj

Maybe I missed it, but how did you secure the panels to the roof?

No, you didn't miss it...I forgot to mention all of it.

The headers, as I said before, are tied to the ridge beam.

However, I neglected to mention how the rest of it is strapped down to the roof...which is what I assume you are asking.

I have a cement tile roof, so screwing any anchors through the tiles to the sheathing (as would be done on a composite roof) is out of the question . So, Hot Sun Industries (Ken Wright's company) supplied anchors that are glued to the tiles.

The anchor is a piece of sheet metal to which a ring is riveted. Squirt some flashing adhesive out of a caulking gun on the back and place it on a roof tile in the desired location. When placing the anchor, for extra holding power I slipped the top edge of the sheet metal under the lip of the tile that overlapped the tile to which I was adhering the anchor.

So, you lay down an anchor every four feet in a line across the roof one foot above the bottom headers and another about in the middle of the panels. Then polymer-covered steel strapping in run through the rings and the ends clamped at the edges of the panels.

For a detailed assembly of the system with pics, you can d/l the Geon Powerstrip manual at www.powermat.com.

HTH,

pj

What size is your pump? How well do the panels work on the second story of your roof? I have some panels and want to mount them to the roof but only have a second story area.

I took the opportunity to throw-out my 20 year old 2 hp pump and installed a 3/4 hp Hayward Northstar. I probably could have gotten away with a 1/2 hp Northstar and saved even more $$ on monthly operating costs.

I'm not sure what you mean by your second question - the panels get full exposure being on the second story, so it is an optimal installation.

pj

I thought mounting the panel on the second story roof was too high.

Too high? Closer to the sun!

The only problem with height (aside from having to work on the second story whilst being affected with acrophobia) is the pump head issue. Is that your concern?

If so, you are certainly correct - it is very important that this issue is addressed. More broadly, the pressures throughout the system must be calculated during the design phase - *not* later.

As far as the roof height is concerned, your pump needs to be able to lift water to the very top of the panels (i.e., the highest point which is the outlet). My outlet is at 25', which is about 11 psi...easily handled by my pump (this is exactly why I say I probably could have downsized the pump even further to 1/2 hp).

The next crucial issue to address is this: you need to tie-in the solar panel outlet into a spot in your return system that is at a *lower* pressure than the pressure generated by the head of your solar panel outlet. The larger your pump, the harder it will be to find this spot. Unless, of course, you have a completely separate return pipe that you can dedicate to the solar.

This is the reason that I strongly encourage anyone who is contemplating this project to examine the webpage on www.powermat.com that addresses mechanical and plumbing design. It clearly explains the issues (with diagrams) that I have only touched upon.

HTH,

pj

Quote:

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Originally Posted by pj1016

Too high? Closer to the sun!

The only problem with height (aside from having to work on the second story whilst being affected with acrophobia) is the pump head issue. Is that your concern?

If so, you are certainly correct - it is very important that this issue is addressed. More broadly, the pressures throughout the system must be calculated during the design phase - *not* later.

pj

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why would the height add to the head? it has to come back down... adding to the equal and opposite head? no?

coreyinsocal - I'm not pj1016 but:

Your right once the system is filled with water less head is needed to keep it moving. But usually there is a vacuum break valve high in the system so the water drains back into the pool when the system is off (for winter freeze protection). So you need a pump that has enough head to pump all that water up to and over the top everytime it starts.

How many square feet of panels do you have???

I have 640 square feet of pool and heat them VERY nicely with 240 square feet of panels. During the heat wave my son forgot to turn them off and the water hit 98 degrees!

Why do you need so much? Are you in Northern Alaska and looking to extend your swimming season beyond the 4th of July?

Two comments:

Drain back is NOT just for "winter freeze protection". It is designed to take a HUGE load off of the panels and your roof when the panels are not generating. If you took a 2 liter soda bottle, filled it with water, attached a hose filled with water, stuck the end in your pool and lifted the bottle, at some point, the bottle would collapse due to the pressure created by the water trying to go down! The same forces are present in a closed solar system - the higher you go (2nd story like mine), the more pressure. Letting the system drain back is like punching a small hole in that bottle, the water drains back, the pressure is relieved and your bottle (or in the real world, your expensive solar panels) DON'T collapse. So, as discussed above, your pump needs to be able to lift water to the highest point in your solar system, in my case that is about 35 or so feet.

As for more is better. I have 55% coverage (450 ft on an 800 ft pool) and would like more. Two reasons, my panels face slightly northeast (only place on the house they could be put), so they generate wonderfully when active, but they are active probably 2 hours a day less than if we had an optimum south/southeast exposure. The 2nd reason is recovery time. When we get a very cold night (we have had nights into the high 40s, low 50s here in lower NY), the pool loses a lot of heat (we don't cover it in during summer, I know that is a big part of it). We can recover about 4 to 5 degrees per day on most days. If we added 50% more panels (maybe on the garage, next year), we would get 6 to maybe 9 per day. That lets us recover from a really cold night or a cold rain storm in one day, instead of 2 or 3. That would be NICE.

Simons99, I think you are fine. You will have 80% coverage, so even on a north/west facing exposure, you should have great generation. That is about the percentage I hope to get to next year by adding a 2nd set of panels of the garage roof.

Don't get me wrong, I am THRILLED with our solar, we shut the system off when we were getting water at 90 consistently. Its just that with the weather so variable here in NY, I think quick recovery time is probably more important than in other areas of the country.