2 Panels Instead Of 3?

[mohawk]

Thanks for the info. We live in a suburb of Minneapolis and I have no idea what degree the sun would be at noon. I'll ask the husband but he'll probably give me that funny look-like why do you want to know that? Denise

[CarlD]

Thanks for the info. We live in a suburb of Minneapolis and I have no idea what degree the sun would be at noon. I'll ask the husband but he'll probably give me that funny look-like why do you want to know that? Denise

Um, there is no hard and fast answer. It changes every day of the year. Of course, it will be highest at the Summer Solstice, when the sun reaches its maximum latitude of 23 degrees and some minutes (The latitude of the Tropic of Cancer--there, when the sun is at its highest, it is directly overhead--90 degrees). So you have to know your latitude (probably 42 or 43 degrees), so the sun at its highest will probably be about 70 or 71 degrees.

If you really want to be exact, get your lat/long off your GPS if you have one. Then you'll need a Nautical Almanac (though you can find them on-line) to find out at exactly what time, at GMT, the Sun is at its highest "Declination" (latitude). You have to adjust for the time difference and then subtract the Declination from your latitude. Then subtract THAT number from 90 and you'll have the sun's angle at exactly that time.

But if your latitude is 43 degrees, the sun will be about 70 degrees....

[chem geek]

And 70 degrees is 20 degrees away from vertical 90 degrees so the lower efficiency by having a flat panel vs. angled is 94% so isn't that much (i.e. just a 6% loss in efficiency). Like I said, I think this "angling" difference will only be an issue for you if you live way, way north in Canada, but at least now you have the tools to know for sure.

As Carl says, the angle of the sun at noontime depends on the time of year. The main reason to have the panels angled isn't so much for the summer solstice time as it is for the beginning and end of the swim season when you more desperately need and want solar heating of the pool. At such times of the year (spring and fall) the sun is lower in the sky (at noontime). Those that live at the equator don't worry so much about these problems, but I suppose they've got other things to worry about!

Richard