Comments on: Does it matter if my solar panels face South or "True South"? http://solarpowerrocks.com/solar-technology/do-i-want-my-solar-panels-south-facing-or-true-south-facing/ The best source for nationwide solar power rebates, tax credits, and incentives Mon, 21 May 2012 20:32:51 +0000 http://wordpress.org/?v=2.9.1 hourly 1 By: Skip http://solarpowerrocks.com/solar-technology/do-i-want-my-solar-panels-south-facing-or-true-south-facing/comment-page-1/#comment-41713 Skip Thu, 03 May 2012 18:22:03 +0000 http://www.solarpowerrocks.com/solar-trends/do-i-want-my-solar-panels-south-facing-or-true-south-facing/#comment-41713 The E stands for east and it is to be subtracted not added The E stands for east and it is to be subtracted not added

]]> By: Oscar Moss http://solarpowerrocks.com/solar-technology/do-i-want-my-solar-panels-south-facing-or-true-south-facing/comment-page-1/#comment-40982 Oscar Moss Mon, 23 Apr 2012 18:06:25 +0000 http://www.solarpowerrocks.com/solar-trends/do-i-want-my-solar-panels-south-facing-or-true-south-facing/#comment-40982 Actually, the more critical consideration is the angle of latitude and time of the year.(date). I wrote a program probably 20 years ago called SOLAR.BAS that I put into the public domain. It calculated the precise angle of solar panel (the old water panels) position to maximize the output. Basically, add or subtract your latitude from the position of the sun. USGS has an online app that you plug in the long, lat. and date, and will tell you where the sun is. Just take it from there. Actually, the more critical consideration is the angle of latitude and time of the year.(date). I wrote a program probably 20 years ago called SOLAR.BAS that I put into the public domain. It calculated the precise angle of solar panel (the old water panels) position to maximize the output. Basically, add or subtract your latitude from the position of the sun. USGS has an online app that you plug in the long, lat. and date, and will tell you where the sun is. Just take it from there.

]]> By: Joe http://solarpowerrocks.com/solar-technology/do-i-want-my-solar-panels-south-facing-or-true-south-facing/comment-page-1/#comment-16861 Joe Tue, 10 May 2011 12:37:25 +0000 http://www.solarpowerrocks.com/solar-trends/do-i-want-my-solar-panels-south-facing-or-true-south-facing/#comment-16861 I had and electric gate installed and it is a 12 volt system with a deep cyle battery. The installer said that he need to point the solar panel North. I was a little confused as I always thought the panel needed to be facing south. It actually facing North East. If I was to turn in around on the same bracket it is mounted to it would be facing South to South West. I believe this is what I should do. Can you tell me if I am right or wrong. It is only a 10 watt panel to trickle charge a deep cycle battery. I had and electric gate installed and it is a 12 volt system with a deep cyle battery. The installer said that he need to point the solar panel North. I was a little confused as I always thought the panel needed to be facing south. It actually facing North East. If I was to turn in around on the same bracket it is mounted to it would be facing South to South West. I believe this is what I should do. Can you tell me if I am right or wrong. It is only a 10 watt panel to trickle charge a deep cycle battery.

]]> By: Dan Hahn http://solarpowerrocks.com/solar-technology/do-i-want-my-solar-panels-south-facing-or-true-south-facing/comment-page-1/#comment-8421 Dan Hahn Wed, 25 Aug 2010 21:08:51 +0000 http://www.solarpowerrocks.com/solar-trends/do-i-want-my-solar-panels-south-facing-or-true-south-facing/#comment-8421 Raja, You want to orient your panels south to take advantage of the sun's arc across the sky for maximum efficiency. Raja,

You want to orient your panels south to take advantage of the sun’s arc across the sky for maximum efficiency.

]]> By: Raja http://solarpowerrocks.com/solar-technology/do-i-want-my-solar-panels-south-facing-or-true-south-facing/comment-page-1/#comment-8401 Raja Wed, 25 Aug 2010 12:05:43 +0000 http://www.solarpowerrocks.com/solar-trends/do-i-want-my-solar-panels-south-facing-or-true-south-facing/#comment-8401 sir what is the reason for facing the solar panels towards south direction sir what is the reason for facing the solar panels towards south direction

]]> By: RassleD http://solarpowerrocks.com/solar-technology/do-i-want-my-solar-panels-south-facing-or-true-south-facing/comment-page-1/#comment-6813 RassleD Mon, 05 Jul 2010 05:33:17 +0000 http://www.solarpowerrocks.com/solar-trends/do-i-want-my-solar-panels-south-facing-or-true-south-facing/#comment-6813 Guys, I just checked the NOAA site http://www.ngdc.noaa.gov/geomagmodels/struts/calcDeclination and found Declination = 14° 16' E changing by 0° 6' W/year W/year for San Francisco. It would appear to me that you subtract this number from the magnetic north reading to get true north because the needle is pointing to the right of what they are calling MN or magnetic north. Lets say we were looking for 150 degrees. Well, would we not really be looking for 150 - 14° 16' or about 136 degrees? Guys, I just checked the NOAA site

http://www.ngdc.noaa.gov/geomagmodels/struts/calcDeclination

and found
Declination = 14° 16′ E changing by 0° 6′ W/year W/year for San Francisco.
It would appear to me that you subtract
this number from the magnetic north reading
to get true north because the needle is
pointing to the right of what they are calling
MN or magnetic north.

Lets say we were looking for 150 degrees.
Well, would we not really be looking for
150 – 14° 16′ or about 136 degrees?

]]> By: John E Lavender http://solarpowerrocks.com/solar-technology/do-i-want-my-solar-panels-south-facing-or-true-south-facing/comment-page-1/#comment-5465 John E Lavender Sat, 12 Jun 2010 15:35:28 +0000 http://www.solarpowerrocks.com/solar-trends/do-i-want-my-solar-panels-south-facing-or-true-south-facing/#comment-5465 Dave, I know it is a bit late but I have only come across your method of finding south (or North) by the sun casting a shadow of a perpendicular pole or stick. You do know that the earths axial tilt is 32.26 degrees and if you were to pick out a nice tall perpendicular ('Vertical' to you) pole and every day, at high noon, place a stone (or some other suitable object) at the end of the poles shadow, at the end of a year you would have enscribed an oval of stones (or some other suitable objects) on the ground. This is because twice a year (once in late March and another in late September) the axial tilt would make the shadow towards the west in march and to the east in September. These are the Equinox, Vernal in March and Autumnal in September. So the right(and only)time to use your pole to align your solar panels is when the Earths axis is perpendicular to to the Earths orbit around the Sun and this only happens twice every year on either 21st of June or December the 21st. These are the only time the shadows point North Dave,
I know it is a bit late but I have only come across your method of finding south (or North) by the sun casting a shadow of a perpendicular pole or stick. You do know that the earths axial tilt is 32.26 degrees and if you were to pick out a nice tall perpendicular (‘Vertical’ to you) pole and every day, at high noon, place a stone (or some other suitable object) at the end of the poles shadow, at the end of a year you would have enscribed an oval of stones (or some other suitable objects) on the ground.
This is because twice a year (once in late March and another in late September)
the axial tilt would make the shadow towards the west in march and to the east in September. These are the Equinox, Vernal in March and Autumnal in September. So the right(and only)time to use your pole to align your solar panels
is when the Earths axis is perpendicular to to the Earths orbit around the Sun
and this only happens twice every year
on either 21st of June or December the 21st. These are the only time the shadows point North

]]> By: Tor a.k.a. "Solar Fred" http://solarpowerrocks.com/solar-technology/do-i-want-my-solar-panels-south-facing-or-true-south-facing/comment-page-1/#comment-2033 Tor a.k.a. "Solar Fred" Tue, 02 Feb 2010 06:25:33 +0000 http://www.solarpowerrocks.com/solar-trends/do-i-want-my-solar-panels-south-facing-or-true-south-facing/#comment-2033 Hey, Mike. It's not going to hurt you all that much. You're going to lose a little bit of power production, but that's not a big deal. Your roof does NOT have to face exactly South, true or not. Plenty of systems get installed on Western systems and Eastern and South Eastern etc. North, now that's a problem. Assuming you've got good subsidies, net metering, and good sun, it's still going to be very cost effective for you. Being a few degrees off South will just mean that it will take you slightly longer for payback. Perhaps 10 years and two months, for example, instead of 10 years. It will be minor. Hope that helps. Hey, Mike.

It’s not going to hurt you all that much. You’re going to lose a little bit of power production, but that’s not a big deal. Your roof does NOT have to face exactly South, true or not. Plenty of systems get installed on Western systems and Eastern and South Eastern etc. North, now that’s a problem.

Assuming you’ve got good subsidies, net metering, and good sun, it’s still going to be very cost effective for you. Being a few degrees off South will just mean that it will take you slightly longer for payback. Perhaps 10 years and two months, for example, instead of 10 years. It will be minor.

Hope that helps.

]]> By: Mike Wilhoit http://solarpowerrocks.com/solar-technology/do-i-want-my-solar-panels-south-facing-or-true-south-facing/comment-page-1/#comment-2032 Mike Wilhoit Sun, 31 Jan 2010 22:41:38 +0000 http://www.solarpowerrocks.com/solar-trends/do-i-want-my-solar-panels-south-facing-or-true-south-facing/#comment-2032 Gentlemen, Are there any figures on power loss as you move away from true south. My house is about 12 degrees west of true south. How bad does this hurt me. Thanks, Mike Gentlemen,

Are there any figures on power loss as you move away from true south. My house is about 12 degrees west of true south. How bad does this hurt me.

Thanks,
Mike

]]> By: Kevin http://solarpowerrocks.com/solar-technology/do-i-want-my-solar-panels-south-facing-or-true-south-facing/comment-page-1/#comment-2030 Kevin Mon, 17 Aug 2009 20:24:56 +0000 http://www.solarpowerrocks.com/solar-trends/do-i-want-my-solar-panels-south-facing-or-true-south-facing/#comment-2030 Hey Guys, You are all technically correct in the abstract yet more considerations must be made. If your area is typically foggy or cloudy in the morning, you are better off facing the panels slightly W of S to maximize gain during the afternoon. Likewise with shading, which you want to avoid at all costs, but if you have some WxSW trees and clear skies in the morning, you are better off facing the panels E of S. Get an experienced local installer to properly evaluate your particular site. Hey Guys, You are all technically correct in the abstract yet more considerations must be made. If your area is typically foggy or cloudy in the morning, you are better off facing the panels slightly W of S to maximize gain during the afternoon. Likewise with shading, which you want to avoid at all costs, but if you have some WxSW trees and clear skies in the morning, you are better off facing the panels E of S. Get an experienced local installer to properly evaluate your particular site.

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