Plastic solar panel considerations
First I would like to thank all members who have replied to my posts in the past. I really appreciate their help.
Pool is infinity edge, approx 20,000 gallons, surface area 525 sq ft. Pump is Intelliflo, with Pentair 520-sq ft Clean & Clear Plus Cartridge filter (oversized to reduce resistance to flow).
I am installing a set of 10 typical FAFCO-type plastic solar panels, each 20' x 2'. The 1.5-inch inlets/outlets of the panels will be connected in parallel between 3-inch flow and return pipes.
I am at the same latitude as Miami and subject to hurricanes, so the panels will be ground mounted, which means that they will be below the water level of the pool and thus always full of water.
In case a panel springs a leak I am thinking it would be wise to put a Hartford loop in the flow pipe just before the panel feeds (there is another one in the main flow circuit that would incidentally protect the return pipe from the panels). Based on the above setup, I have a couple of questions.
1) My main need for heating is between November and March. I was going to build low racks for the panels or perhaps retaining walls to allow me to slope the sand (all terrain is sand here) beneath each panel and achieve a slope of 25 degrees or so. However, the more I look at it the more I am realizing how much work and expense is involved. Would it make more sense to simply lay them flat on the ground and take the hit on efficiency?
I was thinking that an alternative might be to simply add an extra panel or two to recoup the loss in efficiency of laying flat, but how about pressure/pump load - is adding extra panels a problem? I am unsure of the effect, in that extra panels presumably mean more resistance, but there again the additional channels linking the large flow and return pipes might result in less resistance...?
2) There will be times in the summer (90F+ here) when the power is off and the pool is unattended (will use mosquito dunks). Even without that, we are subject to fairly frequent power cuts that can last several hours. What about overheating if the water is not circulating? Are there any precautions I should take?
All input is very much appreciated - flying solo here as no PBs available...