Solar tracking diy?

konstantin.neo
konstantin.neo Registered Users Posts: 19
Hi all.
Time came to put the pv panels on the roof and my dad wants some sort of tracking system. I prefer single axis tracking, with a micro-controller that moves the actuator to the position where to sun is supposed to be, the other axis adjustable manually for seasonal settings.
Does anyone know of DIY or open source projects about solar tracking?
I am googling but are yet to find something I could use.

Comments

  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Solar tracking diy?

    Just a thought,,, with PV prices as low as they are, it might make better financial sense to add a few watts of panels to make up for positional loses. It might work out cheaper per kwh.

    Tony
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: Solar tracking diy?

    FWIW - As the cost of panels has decreased typically it would take a dramatic situation to make tracking cost effective over additional panels. Perhaps in far north at a high elevation where the sun moves 270+ degrees and doesn't rise too high above the horizion...just my opinion sorry I didn't address your question, but it should be worth a cost evaluation.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • konstantin.neo
    konstantin.neo Registered Users Posts: 19
    Re: Solar tracking diy?

    I'm not into purchasing 10k+ trackers. Something modest but functional. Also I need to see how much will it cost to me compared to what the panels cost me. I like to build things and if you know of open source tracker projects don't be shy, post :)
    Attachment not found.
    I have 12 panels right now. Could use one of those to swing 3 panels at once (one string), panels are 32x64.
  • Volvo Farmer
    Volvo Farmer Solar Expert Posts: 209 ✭✭✭✭✭
    Re: Solar tracking diy?

    I'm going to post a contrary opinion here. I wanted my panels on top of pole mounts, and it hasn't cost me any more to weld up frames on top of old C-band dish mounts than it would to build a stationary mount. They're getting more scarce now, but for a while there you could get old C-band dishes for free that people abandoned in favor of little dishes. Every one I got came with a working actuator too.

    I use the Redrock trackers and even optioned out the way I want them, I think I pay around $45 each. To me, it wasn't worth fooling around building my own circuit board for $45. The end of travel switches are built into the satellite dish actuators, the Redrock trackers park in the east, and if I ever get tired of fooling with trackers, I can park my arrays due south and forget about it.

    When I first decided to do this, panels were $4/watt, but I still think if you are going to DIY your panel mounts, it's not any more expensive to make them so they can track.
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Solar tracking diy?
    I'm not into purchasing 10k+ trackers. Something modest but functional. Also I need to see how much will it cost to me compared to what the panels cost me. I like to build things and if you know of open source tracker projects don't be shy, post :)
    Attachment not found.
    I have 12 panels right now. Could use one of those to swing 3 panels at once (one string), panels are 32x64.

    What you are showing is a horizontal axis tracker. That would be useful primarily for summer/winter variations as a manual adjustment and contributes relatively little during the primary sun hours when the sun is reasonably high above the horizon. (Unless you are near the equator where a horizontal axis tracker could go from east to west :-) .) Instead, for automated tracking, you would want a vertical axis tracker to follow the sun from east to west every day. The additional benefits of a dual axis tracker really do not justify the added expense there. (A mirror-concentrator solar heat collector would obviously be a different story, but PV is pretty tolerant of small angle variations.)
    SMA SB 3000, old BP panels.
  • Ken Marsh
    Ken Marsh Solar Expert Posts: 114 ✭✭✭✭
    Re: Solar tracking diy?

    Hi Kon,
    Good question. It seems like I have spent the last year trying to get a single axis array to track.
    You can buy tracking heads, boards with photocells aimed different angles, which will with servo mechanisms track the sun.
    I got a couple off ebay and they do work when the sun is shining but get confused when cloudy or completely overcast.
    It is statistically better to follow the sun even though you can not see it.
    But there will be times when the cloud cover is thin and brighter elsewhere.
    However this changes rapidly and by the time your array gets there it will change.
    My array takes about ten minutes to go lock to lock.

    Right now I am using a duty cycle timer. It runs the motors about 20 sec every half hour.
    In the evening when we run out of light, one of the Charge Controllers signals via its Aux contact.
    This runs the array back to the east where it parks for the night.
    When the sun comes up the next day the panels are already looking east.
    The charge controller closes the Aux contact when it gets enough sun for about a half amp charging current.
    The cycle repeats.

    There is a further advantage to trackers. You can park the panels vertically.
    We are not in a good area for sun and have lots of snow and dew.
    The sun has to burn off the dew before you get good output.
    Vertical surfaces get significantly less dew build up hence the array comes up to full charge rate sooner.
    As for snow, if you start the day with no snow the sun will usually stay ahead of snow build up.
    You don't want to turn the panels upside down because they can fill up with water.

    And that is a neat illustration.
    Have you drawn up details?
    This array is all on one axis, 20 panels, 75 ft long.
    Axis is North South which favors summer.
    I am running aircondx and we hardly get enough sun in the winter to bother with.

    By the way, it dosen't work to seasonally adjust the panels because they shade each other
    unless you can raise the end of the whole array.
  • garlic
    garlic Solar Expert Posts: 43
    Re: Solar tracking diy?

    I use a tracker much like the one in the illustration.With 5 100w panels. It seems to equal a 900 watt static array here at 3400' and 40N degrees in the summer.
    Someone here has said,a tracker will extend the life of your batteries.
    My tracker is operated by a 110v winch and counter weight operated by a switch in the front room.
    It feeds the 24v battery bank though a Morningstar mppt 45.
    I like the simplicity and stability of polar axis trackers.
  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    Re: Solar tracking diy?

    I'll toss my 2c in on this conversation, although with inflation it's probably more like 0.02c. ;) Anyhow, have you seen the TV show "The Colony". While it's obviously a stagged survival experiment designed to create good TV (or bad, depending on your viewpoint) they do bring up a good recommendation in season 1 for an auto-tracking system based on two light sensors attached to the frame, one of which acts as the trigger and the other as the control. Check out the info on Episode 5 as it'll clarify what they did a bit. Believe it or not, it's probably one of the cheapest and best DIY solar tracking systems I've ever seen. (http://en.wikipedia.org/wiki/The_Colony_%28U.S._season_1%29)
  • gavpop
    gavpop Registered Users Posts: 1
    Re: Solar tracking diy?
    Hi all.
    Time came to put the pv panels on the roof and my dad wants some sort of tracking system. I prefer single axis tracking, with a micro-controller that moves the actuator to the position where to sun is supposed to be, the other axis adjustable manually for seasonal settings.
    Does anyone know of DIY or open source projects about solar tracking?
    I am googling but are yet to find something I could use.



    Hi,

    I had the same issue as you - trying to find a decent DIY tracker.
    There are lots of rather expensive commerical ones, but they were out my price range.
    Instead I decided to build my own....you might like to have a look at it - http://www.binaryorbit.org


    Gav.
  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Solar tracking diy?
    Hi all.
    Time came to put the pv panels on the roof and my dad wants some sort of tracking system. I prefer single axis tracking, with a micro-controller that moves the actuator to the position where to sun is supposed to be, the other axis adjustable manually for seasonal settings.
    Does anyone know of DIY or open source projects about solar tracking?
    I am googling but are yet to find something I could use.
    Trackers on a rooftop are problematic. Dead load and wind loading are an issue and you have to pay a lot of attention to spacing to avoid self shading.
  • t00ls
    t00ls Solar Expert Posts: 245 ✭✭✭
    Re: Solar tracking diy?

    if I may.... we were showing off some of our tracker building techniques on another thread

    http://forum.solar-electric.com/showthread.php?15307-solar-tracker-finished

    mine costs right at $ll00 to build

    was it worth it,? I think so, but Im off grid also, and I need that extra bit of sun.... I have seen a tracker built through the roof of a house...quite neat indeed
  • rplarry
    rplarry Solar Expert Posts: 203 ✭✭
    Re: Solar tracking diy?
    I'm going to post a contrary opinion here. I wanted my panels on top of pole mounts, and it hasn't cost me any more to weld up frames on top of old C-band dish mounts than it would to build a stationary mount. They're getting more scarce now, but for a while there you could get old C-band dishes for free that people abandoned in favor of little dishes. Every one I got came with a working actuator too.

    I use the Redrock trackers and even optioned out the way I want them, I think I pay around $45 each. To me, it wasn't worth fooling around building my own circuit board for $45. The end of travel switches are built into the satellite dish actuators, the Redrock trackers park in the east, and if I ever get tired of fooling with trackers, I can park my arrays due south and forget about it.

    When I first decided to do this, panels were $4/watt, but I still think if you are going to DIY your panel mounts, it's not any more expensive to make them so they can track.

    Kon
    I agree with VF, and you say you enjoy building things so this project will be right up your alley. You can get a solar tracking head here: http://www.redrok.com/electron.htm#led3x
    I used the CB with the anti reverse, it saves the servo from "hunting" after it finds the sun on each move. You can get the satellite actuators here: http://www.primefocusantenna.com/index.php
    Get the good actuator, more expensive but will last for years and years. Do not even bother with the ebay Chinese actuators, they don't last but a few months.

    While I do agree with others that with the lower price of panels now makes a tracker unnecessary, the satisfaction of building your own and gaining 40% over a stationary array of the same size is worth the time and expense.
    Good luck with yours.
    Larry
  • TnAndy
    TnAndy Solar Expert Posts: 249 ✭✭
    Re: Solar tracking diy?
    rplarry wrote: »
    . You can get the satellite actuators here: http://www.primefocusantenna.com/index.php
    Get the good actuator, more expensive but will last for years and years.
    Larry


    I agree on the Chinese actuators.....plastic gears, pieces of junk.

    But the website above for Venture actuators is HIGH priced.....I bought a heavy duty 36" directly from Venture for 150 bucks less than the price of the one on that website.
  • rplarry
    rplarry Solar Expert Posts: 203 ✭✭
    Re: Solar tracking diy?

    TnAndy
    Can you post that link again, it doesn't link for me or just give the web address. I am always looking for better deals.
    Larry
  • TnAndy
    TnAndy Solar Expert Posts: 249 ✭✭
    Re: Solar tracking diy?

    Larry,

    You mean Venture actuators ?

    http://www.venturemfgco.com/

    They have a good tech department too if you need info or have problems with one of their actuators.