New array and tracker

Discussion in 'Off Grid Living' started by TnAndy, Feb 16, 2011.


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  1. TnAndy

    TnAndy Senior Member Founding Member

    Stopped by the machine shop today, and picked up the start of my next tracker mount for the next array of panels going up.

    This one is going to be 10 245w Solarworld panels on a dual axis mount this time ( previous two are single axis, east/west trackers ). The other axis will tilt the entire array on the horizon angle to compensate for the sun angle from summer high point to winter low point.

    Hope to pick up another 8-10% more watts that way.

    Don't plan to power it on a daily basis, I figure to make is a manual crank thing where I adjust it once a month or once a quarter.

    Making the whole mount/pole "beefier" this time too. Last one, I used a 6" sch 40 steel pipe, this one will be 8". Putting 10 panels that are 18sqft each on it, so that's 180+ sqft feet of "sail" area up there for the wind to hit....beefier can't hurt.

    This one will also be higher in the air....last time, I had a 20' pc of pipe cut off in half, and put it 3' in concrete ( 4'x4'x3'deep ),leaving about 7' out of the concrete.

    This one was a 16' pc of pipe I found at the scrapyard, so I'm using the whole thing, making the top of the pole about 12-13'.

    At one end of the pipe, what will be the top of the pole, I had the machine shop mount a 2" flange type bearing on each side, with a 2" steel shaft running thru the pipe and bearings, sticking out about 3" outboard of the bearings.

    To that, I plan to weld up a rectangular shaped "box" of 3" square tubing ( depending on what I can scrounge) that will measure the same width as the shaft is long, and about 5' in length. This will be welded at the mid point to the 2" shaft coming out of the pipe. Once the pipe is set vertically, the shaft will be horizontal, and this "box" will be oriented north/south. This is the horizon tilt for the array.

    Then, on top that box frame, I'll mount a couple of 2" pillow block type bearings, same as the other arrays, and weld up a frame to it that will be the east/west tilt.

    This will all make a whole lot more sense with the pictures that will follow.......but basically, picture a kid's seesaw that not only goes up and down on the seat ends ( that's one axis ), but also tilts left/right at the center point....from about 20 degrees for the summer low, to about 55 degrees for the winter high angle. ( which is the other axis ).

    Pics to follow over the course of the next month or two, as I have time and funds to work on it.
     
  2. Nadja

    Nadja RIP 3-11-2013 Forum Leader

    I would be the most concerned over the double axis vs. the wind. Not to mention, that if I had your money, I would burn mine. Of course burning mine would be tough, cause first, I would have to find it .. Does copper burn ? LOL Nice
     
  3. TnAndy

    TnAndy Senior Member Founding Member

    Wind isn't a huge issue here.....I live in the lee side of the mountain, and the prevailing west winds blow over the top. I can hear it howling up there ( 800' elevation above ), and it barely be doing anything down here. Don't get the kind of wind you do there. I lived in Springerville for a while, and saw a 55gal drum fly thru the air.....I mean 50' up, never touched the ground....... one March during the month of wind.

    And the arrays aren't "free"...they will be anchored at the bearings, and by the actuator point.
     
  4. melbo

    melbo Hunter Gatherer Administrator Founding Member

    Wind?
    IMG_4700 (Medium).JPG
     
  5. TnAndy

    TnAndy Senior Member Founding Member

    Nah....wind sucks...... :D

    Pic of the end of the pole which will be the horizon axis mount. 2" flange bearing mounted on either side, with 2" shaft sticking out 2.5" outboard of the bearing race. Gonna wire brush the pipe down today and get a coat of primer on it.

    [​IMG]
     
  6. hank2222

    hank2222 Monkey++

    Or how about a super short tower for the wind turbine set up for your place withthe turbine set up higher up on the hill for use with a smaller tower and turbine system .. Check out the Solar Stik website for ideas about a home made verison of the wind turbine stand ..That what i did and took a couple of the ideas that they had and expanded on them with a diff style of adding more solar panels to the unit with a leg system i design on a piece of paper before going over and welding the design up for use on the land ..
     
  7. SLugomist

    SLugomist Monkey++

    Think of what you could do if you converted the panels to mirrors and used a lense to focus it Boo ha ha Sitting on the top of the hill, shooting a sunbeam.
     
  8. TnAndy

    TnAndy Senior Member Founding Member

    OK, been a bit since I had time to work on this, and update the thread. Got the north/south tilt section built and welded to the axle on the pole:

    Basically, a rectangle of 3" sq tubing that the east/west mount will sit on...

    [​IMG]

    Different view of it. The east/west assembly mounts on the studs sticking out of the raised section. The linear actuator that will operate the north/south tilt goes where that pc of Unistrut is now temporarily bolted.....didn't want to damage the actuator when I haul the pole up on the hill to set in place.

    [​IMG]
     
  9. TnAndy

    TnAndy Senior Member Founding Member

    Here's the 24" actuator that will power the north/south tilt:

    [​IMG]


    Similar one, 36" stroke, is what runs the east/west movement.
     
  10. TnAndy

    TnAndy Senior Member Founding Member

    The east/west tilt assembly is an axle of 2" steel, 60" long, welded to a frame of 2" square tubing.

    [​IMG]

    [​IMG]
     
  11. TnAndy

    TnAndy Senior Member Founding Member

    Then, to mount the panels themselves, I'll be bolting some 208" long sections of electrical Unistrut bar to the top of the east/west frame, at a 90 degree angle.....like so.....there will be 4 pcs of that......each side of the tilt frame will hold 5 panels.

    [​IMG]

    The panels will mount to the Unistrut with these Unirac PV S-5 mounts:

    [​IMG]

    These clips are meant to mount to standing seam roofs, but will work equally well on the sides of the Unistrut....lot easier than the L clips I had made on previous mounts, and had to run a self drilling screw thru the clip into the side of the panel WHILE up in the air trying to hold the whole mess. We used these Unirac PV mount clips on my buddies off grid cabin to mount his panels to his standing seam roof, ( no hole penetration ! ), and they worked like a charm.....so I decided to spring for them on my new mount as well.
     
  12. TnAndy

    TnAndy Senior Member Founding Member

    My track hoe buddy is here tomorrow to dig me a hole for the base concrete, and we'll set the pole in the hole and brace it up until I can get the concrete pumped up to it, hopefully sometime next week.....then it's panel mounting and wiring time.....few more weeks, and this array "should" be up and running.
     
  13. ghrit

    ghrit Ambulatory anachronism Administrator Founding Member

    I may have missed something along the way. Are you planning to go completely off grid, or continue to backfeed the utility? (Or have the ability to do both ---?)
     
  14. TnAndy

    TnAndy Senior Member Founding Member

    I'll continue to back feed the grid......they pay enough to make it worth while.

    This third array should end my bills forever, and actually generate a small profit ( like 600-800 ) at the end of the year. If you have a credit amount end of December, they cut you a check. Right now, I'm only 20 bucks ahead with the two original arrays......one at 1450, one at 1750.

    Got two more panels to go on the 1450 array to bring it up to 1750, then this new array will be 2450, for a total a shade under 6kw....that's it....I'm done unless I start stacking on more inverters, which I don't plan on doing.

    That was one reason I decided to go with another array.....I wasn't maximizing my inverter capacity....had them already in place, but wasn't getting "full use".

    Right now, we're generating about 1/3 of our annual use.....( over 60% in months like the last two, but it falls off significantly in the winter )....with this addition, I should stay above 50% year round, and be right at 100% many months.

    We have two different meters.....the normal "buy" meter, and the "solar sell" meter.....which records all solar generation, since they pay a premium ( 12 cents over retail ) for that power.....that's HOW we can generate less than 100% of our needs, and still have a credit....

    The "buy" is bi-directional....during the day if we generate more than we need, it turns backwards as the power flows out to the grid. Right now, that meter has about 21,000kw/hrs on it.....my goal is to back that puppy down to ZERO over the course of a few years.....ahahaaaaaaa....dang if THAT won't screw with the power companies computers......
     
  15. beast

    beast backwoodsman

    i used to install and service those big satellite dishes
    did it for several years before the whole thing went south
    one thing i learned was no matter how well you concrete them in,
    they still move, not always a lot, but they do move
    what we did was build a 4-post cage using 3/4 inch threaded rod
    we set this in concrete with 8 inches sticking up above
    we welded a 3/4 inch plate to the bottom of the poles and drilled holes
    to line up with the 4 threaded studs
    we put a pair of jam nuts on each stud, below with washers, no lock washers tho
    then set the pole up with the plate on the studs
    another washer on top, then 2 more jam nuts
    by adjusting these nuts you can relevel the pole in a few seconds
    saved a lot of time and money digging out shifted poles
    and restting them
    for what youre doing with the arrays it might be to your benefit to use this system
     
  16. TnAndy

    TnAndy Senior Member Founding Member

    I'm setting them in concrete 4' x 4' x 4'. Moving ain't really a problem.
     
  17. beast

    beast backwoodsman

    yeah, i used to think that too
    ive personally dug up
    chipped off
    and reset a pole that was in 4x4x6
    the earth moves
    constantly
    good luck
     
  18. TnAndy

    TnAndy Senior Member Founding Member

    Interesting..................

    A small amount of movement probably wouldn't do much, as these things are moving all day long anyway.....the only real effect would be if they got much off South, which means they would have to twist considerably.....whereas a sat dish that has to have a pretty close tolerance to a sat out 23k miles, a slight movement IS a big deal I'd say.....
     
  19. beast

    beast backwoodsman

    id at least leave a couple inches extra adjustment space
    on each end of your elevation adjusters
     
  20. BTPost

    BTPost Old Fart Snow Monkey Moderator

    Sun energy is about 8 degrees wide, where as Geosynchronous Sat slots, are every 2 degrees..... FYI....
     
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