solar panel expectations

Jun 4, 2008
Western NY
I'm wondering if any experts can help determine whether my expectations were too high on my purchase. I have (2) 4x 20 solar bear panels 12ft away from my 24' ag with approx. 13,500 gal capacity. I ran them for 4 hours in good sunlight (south facing) and was a bit diappointed to see a 1 degree increase. In the past, I've observed a 1 degree increase on 4 hours of sun prior to installing the solar panels. The panels appear to be plumbed correctly (I did it myself) and I followed the instructions from Fafco religiously. While the pump is running water through them, the panels feel nice and cool when compared to the adjacent roof surface. I shut it down for about 30 minutes and the panels felt warm. The air temp was about 68 degrees, the water temp was 70 (using a solar cover religiously) and got to 71 before we lost sunshine that day.

If this seems correct, then with 4 hours of pump running to circulate water through the panels to gain 1 degree seems that on a full sun day for 10-11 hours (pool and panels are in full sun from dawn to dusk) I should only see 3 or 4 degrees??? I was hoping to see 10- 12 degrees.

Any input would be appreciated.



LifeTime Supporter
Oct 5, 2007
Valrico, FL
How many square feet is the surface of your pool? Mopst recommendations is to have the solar panel area about 50 to 100% of the area of your pool. With two 4x20 panels you only have eighty square feet of solar panels. That is not much. I have an inground pool, 7500 gallons and have 240 square feet of solar panels. And I am in Florida! I would say that you need more panels.
Jun 4, 2008
Western NY
...80 x 2= 160sf of solar panel. A 24' circle is about 452 sf. With that, I'm way undersized. I read that (1) 4x 20 panel would heat a 24' pool.... I don't remember where this came from. It may have been a website selling panels. Would that be a marketing scheme? If they told me to buy (9) solar panels at $240 each, I would not have done it. There just isn't enough sunny days up here to utilize a solar system if the cost is $2000 or so.

Thanks for your input.


Mod Squad
TFP Expert
Apr 4, 2007
SW Indiana
The recommended sizes are of dubious value. Most of them are based on the idea of nearly year round pool operation. The panels you have should be able to make a noticeable difference in your pool. I suspect you are asking a lot with air temps that low and such a short day of sunlight.


LifeTime Supporter
Apr 15, 2008
Midland, Ontario
If your air temp was 68, in my limited experience you won't see too much gain. I have 160 sq ft of panels for a 16x40 IG pool. We had a cool season so far, and I struggled to get into the high 70s for a while. We had a really hot weekend a few weeks ago and I went from 70 to 85 in 2 days running the pump during the day with the solar cover on. When its nice and warm/sunny out, standing in front of the return, I can feel the warm water. It does help keep a constant temp, I haven't gone below 80 since that weekend, and we have had cool days and colder nights since (single digits!)


Well-known member
Jun 16, 2008
S.E. Wisconsin
We've got 3 2x20 panels mounted on our south facing garage roof for a total of 120 sq. ft. The panels get full sun from 9:00 a.m to 5:30 p.m. and on a good day like today (full sun, 90* air temp) they heated our pool (5700gal) from 78* to 89* with a solar cover on. If it's sunny tomorrow I have no doubts it will be in the high 90's and I can gaurantee I will not want to get out. :mrgreen: