Solar panels 36’ above the pool. What pump ?

[JeffKL]

Hello

Wondering if I can put a solar panel on my roof. It’s 36’ above the pool. A flat roof with plenty of space and sun. I have a tiny yard with lots of shade. The only place for panels is that high roof 3 floors up. The house shades the pool after 4Pm.

I currently run a 1.5 hp variable speed pump for the pool. No salt. 5k gallons.

How feasible would it be to pump water that high? I can live without solar, but if it’s not too complicated and expensive (electricity/size pump) I’d like to add solar.

What I really what to do is run a solar powered 12v pump for the solar system. I’ve got plenty of roof space available.

I currently have a 2x20 solar water panel. Basically a $200 roll up plastic tube mat. It works great just laying next to my pool on the patio. But it need a permanent home not just laying on the patio. And it needs more hours of sun.

Can i use a 1hp pump? Can I use a small lift pump to get it up then maybe a 12v pump on the roof to get more pressure. I’ve got several 12v pumps for my offshore boat. Bilge bumps. Wash down pump. Bait tank pump.

 

[ajw22]

Welcome to TFP.

@mas985 can help with pumping and @Dirk may have thoughts on the flat roof.

Solar Pool Heaters - Further Reading

www.troublefreepool.com

 

[JamesW]

How much flow in GPM will the panels require?

How much total solar panel area?

 

[mas985]

Wondering if I can put a solar panel on my roof. It’s 36’ above the pool. A flat roof with plenty of space and sun. I have a tiny yard with lots of shade. The only place for panels is that high roof 3 floors up. The house shades the pool after 4Pm.

When you say flat, do you really mean 0 slope or very slight slope? Having just a very slight slope will help the panels drain a little faster although given your location, even a perfectly flat roof will still drain the panels sufficiently.

I currently run a 1.5 hp variable speed pump for the pool. No salt. 5k gallons.

How feasible would it be to pump water that high? I can live without solar, but if it’s not too complicated and expensive (electricity/size pump) I’d like to add solar.

Most like that should be fine but it does depend on the make an model of the pump. Not all 1.5 HP pumps will have the same head curve.

What I really what to do is run a solar powered 12v pump for the solar system. I’ve got plenty of roof space available.

I doubt that type of pump would work at 36'. Do you have a make/model in mind?

I currently have a 2x20 solar water panel. Basically a $200 roll up plastic tube mat. It works great just laying next to my pool on the patio. But it need a permanent home not just laying on the patio. And it needs more hours of sun.

Can i use a 1hp pump? Can I use a small lift pump to get it up then maybe a 12v pump on the roof to get more pressure. I’ve got several 12v pumps for my offshore boat. Bilge bumps. Wash down pump. Bait tank pump.

Why would you not use the existing VS pump?

Again, the pump depends on make/model. You cannot size a pump solely on it's HP rating.

 

[Dirk]

Sorry, I don't have any experience with installing solar panels on a flat roof. But I expect some similar principles apply.

Mark mentioned the draining. That is most important in climates where the panels could freeze. Maybe that's not an issue in Key Largo? But there is also a need for an incline for optimum panel heating efficiency. Ideally, the water should flow equally in every square inch of the panel, and if you have a low spot in the wrong area, that could impact efficiency. The water needs to flow from one corner, across the manifold, up the tubes, across the other manifold, and then exit out the opposite corner. You don't want water getting trapped in a "dead" corner. The animations on the following website explain the theory. They. also have articles about installing on flat roofs.

The flat roof bit starts on the home page. Then check out each link under the "How It Works" tab, especially the animation that addresses panels tilting the wrong way. There are also articles about pumps, etc.

Hot Sun Solar Swimming Pool Heating with Flexible Solar Collector Panels

The state of the art in the adaptation of solar pool heating to various roof types and pool mechanical systems.

www.h2otsun.com

The other thing to be aware of: solar panels expand and contract throughout the day and night. If the little tubes are laying directly on the roofing surface, and that surface is at all abrasive (like most roofing surfaces are), then the expansion and contractions will "saw" the tubes across the sandpaper-like surface, and might eventually cause premature failure, literally wearing holes right through the panel material. That's not great for your roof, either.

 

[JeffKL]

The roof is completely flat. It’s a concrete roof in Key Largo. I experimented by running a hose from my pool pump. Pressure was much too low. On to plan B.