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Forum Index : Solar : Dual Tracker Plans
| Author | Message | ||||
| floodrod Regular Member  Joined: 08/07/2009 Location: Posts: 70 |
Figured I'd share my dual tracker plan in case anyone is looking to build one. I am seeing if I can get my engineer to calculate square foot wind load capacity. Plan does not show location of actuator attachment points as that will vary with location, actuator length, and pole choice. Critiques Welcome 
Edit- Oops, upload resized it- here's a link to full size- http://www.unexplainable.com/images/mount-plan.jpg |
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Downwind Guru  Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
One would think the cost of the build to be a negative compared to the cost of extra panels to equal the same result. Years gone by the panel cost was high and we built trackers, now the panel cost is lower and its cheaper to just add panels for a smaller cost than building a tracker for a equal or greater return in power output. All you can expect is a 15-20% output increase at the very best, so do the math on build costs compared to that in panel costs. Pete. Sometimes it just works |
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| floodrod Regular Member Joined: 08/07/2009 Location: Posts: 70 |
Downwind- Your logic is flawed. You are comparing apples to oranges. If you have panels you wish to mount on the ground, you have 2 choices.. 1. Build yourself a properly designed stationary solar mount OR 2. Build a Tracker Mount.. The material list is relatively the same for the most part. Whether stationary or on a tracker, the square footage is the same. You will need the same amount of strut and supporting metal either way. The tracker will have 1 big footer and pole as opposed to several smaller footers and poles. Throw in a pair of hinges and actuators and you get more power over the stationary mount.. How much more power?? The nay sayers play the low side and say 15-20%. The retailers play the high side and say up to 60%. Actual studies say: "Seasonally in California, gain ranges from 20 to 30 percent in winter (October through March) to between 40 and 55 percent in summer. In general, a tracker adds most to output during the hours when a stationary array produces the least power." Average the lowest with the highest and you get 37.5% It seems you're comparing building a tracker to throwing them on an already existing 2x4 mount. Obviously you save more when you don't factor in the cost to mount them. |
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| brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
You'll have a lot of fun building it --that has to be considered. The 10 foot long side members are a bit on the light side ,I'd reckon,from my own tracker.. 2x1 1/2 x 3/16 will twist and easily bend/wobble. My is built with TV tower Steel members(they upgraded the tv tower close by and I scored a trailer load of used steel bolts Etc) Most of my steel is 3x3x1/4 structual steel heavy gal. I do get 100kph winds and I do live on the side of a cliff,so the wind forces are considerable. Go heavy in all the steel dept. otherwise, she'll twist and rattle and shake .The panels WILL shatter. But , most important, have fun ,I have. Bruce Bushboy |
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| floodrod Regular Member Joined: 08/07/2009 Location: Posts: 70 |
Hi bruce, Yes it's fun. I considered going heavier as you suggest. But the darn thing with no strut or panels weighs about 175 pounds as pictured above. It was a challenge getting that frame on top of an 11' mast from the low side of a mountain. I plan on having an engineer evaluate the plan and give load ratings and max square foot panel surface at XX psf wind variables. Thanks for the input! |
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| brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Looking back at your plans,I see one part that maybe could be improved .. That 11 foot ,out of the ground pole mount .. Boy, that is a very tall central pivot ,mine is about 4-5 feet max and the reason I kept it down was exactly what this whole topic is about -- twist,sway,rattle and hum ... You have to do something about this height.. Maybe cut into your high side ground a bit to get your rotation?. By the way , I found that the side brace worked a treat, she settled the twist and sway down to nil,allmost. We had a storm here yesterday ,100 kph winds buffeting my array ,,she was fairly well rock solid. have fun ,remember, you'll not want to do it a second time with broken bits.. Bruce Bushboy |
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| floodrod Regular Member Joined: 08/07/2009 Location: Posts: 70 |
Haha.. Back to the mount. Wish I would have just ordered the 8" pipe! But it's getting real strong- every piece I weld on is helping. It will be rock solid (literally) this week, once I encase it in concrete. I can't go much mower because my house is between it and the sun. And the grade goes up about 40 degrees slope in back of it (its on the side of a mountain). At first I was going to do 2 arrays and split the panels, but I couldn't get past the shading from the first array. I would have to clear lots of woods to get the angle. I'm still looking for your array pic. Where is it? |
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| brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Hi Foodrod, can't post pic 's til I get the tech to sort out the problem . The link below shows some pic's of my tracker , down around the last pages, I think .. http://gallery.anotherpower.com/ Bruce Bushboy |
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| brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
I,m on my I pad,so I,ll see if I can post from here. 
Bushboy |
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| floodrod Regular Member Joined: 08/07/2009 Location: Posts: 70 |
Nice Bruce.. Cool design! |
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| floodrod Regular Member Joined: 08/07/2009 Location: Posts: 70 |
Worked Out Well. Got Engineering Data Back.. To support 215 sq ft of panels in 90 MPH winds, the main 10' rails need 2x Double Channel A1200 Superstrut welded back to back attached to the main rails. This is enough support to handle 5' cantilever of panels on each side of the frame, totaling 20' length. The frame design is suited to handle 129 square feet of panels in 90 MPH winds with 2 pieces of Single A1200 Superstrut rails. And the encased I beam engineering came back as enough to easily support the whole array in 90 MPH winds. Finally getting accustomed to the new absorb / float settings and getting the battery bank charge parameters balanced. First time I seen the watt display pass 2,000 watts was today :) |
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