[RE-wrenches] Spacing between ground mounted sub-arrays at 48.5 degrees N latitude

[William Korthof]

I did a 246 kW ground mount  installation in Simi Valley with an 11 degree slope ESE... Same issue as what you are facing.  

You can easily see the system from satellite images: ~1 mile north of HWY 118 at Kuehner Dr exit in Simi Valley, CA. 

We used Unirac's ULA rack system with 40 rack groups of 50 modules each... Poles are vertical in the ground, but the normally horizontal poles were affixed to them at an 11 degree angle to match the ground slope; the top of pole "T" units were custom welded by the manufacturer to our angle for this purpose (in our case, 79 degree/101 degrees). Each rack also slopes about ~17 degrees from the back legs to the front legs. Net slope of the array is effectively turned near more south than the slope, while still optimizing for a small array footprint. 

/wk

William Korthof
714.875.3576
Sustainable Solutions
#956904

On Feb 16, 2014, at 1:35 PM, Bob Clark <bclark at solar-wind.us> wrote:

Wrenches:

I have a customer who wants 40 solar modules on ground mounts (not poles) in an area that slopes to the ESE at 7 degrees.  Putting these modules on one ground mount assembly so that the modules are in a 0 degree slope East to West would leave the east end about 20 feet in the air.  Not acceptable as the customer wants a profile as low as possible for aesthetic reasons plus the wind can be quite strong on occasion.

So, I am trying to figure out how far apart 5, 8 module sub-arrays (landscape orientation 2 E-W by 4 N-S tilted at 35 degrees S from the horizontal) would have to be North to South and East to West so that they are low profile yet do not shade each other on the winter solstice at 48.5 degrees N latitude.  These calculations are complicated by the ground sloping to the ESE at 7 degrees.

Can anyone point to an online calculator that takes into account the slope of the ground?  Or can anyone help me with the geometry of this situation.  I have gone around in circles and thoroughly confused myself.

Thanks in advance.

Bob Clark
bclark at solar-wind.us



_______________________________________________
List sponsored by Home Power magazine

List Address: RE-wrenches at lists.re-wrenches.org

Change email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out participant bios:
www.members.re-wrenches.org