Solar trackers

[Watt]

I've asked a few folks about trackers and I've received all sorts of different replies.  I don't have time to build the electronics but I do have the time and means to do the steel work for the mounts, do any you have experience with this sort of tracker?  http://www.ebay.com/itm/DOUBLE-AXIS-SOLAR-SUN-TRACKER-CONTROL-PANEL-/130625373214?pt=LH_DefaultDomain_0&hash=item1e69e1041e  If you know of one better or have one to offer for sale, let me know.  Thank you

[WooferHound]

That tracker in your link looks like it requires a computer to function ?

It says "DC 24 – 36V 10 A"
then it says "UNIVERSAL INPUT-  AC 110-240V   50/60Hz"

[bj]

   I have been doing the same mental gymnastics on this as you Watt, and every time I add up the dollars, I just
decide to put the money in more panels.  At $1 a watt,  the tracker you showed could buy me two more panels.
   Not saying I'm right, as experience may teach me otherwise, but that's how it looks to me right now.
  Good luck figuring out what's best for you.

[Watt]

Woof, I'm thinking the input is the ac and the output from 24v to 36v is for the tracking motors. 

bj, I talked with Ross once about his trackers and he mentioned a pretty substantial difference in output by making the panels track the sun.  If I remember right, it was something like a 40 to 50% increase.  I'm thinking of adding the tracker due to having a new 4kw solar panel array just waiting to be put to use.  if I were to buy another 2kw it would be way more dollars than making these track.  Plus, the real estate for mounting.  I need to build another RV cover and when I do, I will build the roof to pitch around 20 degrees + and - just for solar panels.  Until then, I am limited on proper roof orientation and want to get the most bang for the buck. 

I wish I had the electronic skills to build a proper tacker. 

[rossw]

bj, I talked with Ross once about his trackers and he mentioned a pretty substantial difference in output by making the panels track the sun.  If I remember right, it was something like a 40 to 50% increase.

Just for clarity, I'm talking about WATT-HOURS PER DAY OUTPUT, not instantaneous output.
The tracker doesn't make a 100W panel magically produce 150 watts.
But a panel that follows the sun all day makes me about 40% more watt-hours a day than an un-tracked one.

[Watt]

Thanks Ross, I did make my post sound as if they would produce more than their name tag.  I didn't mean that at all but I will say by using the Midnite Classic, I have seen higher than name tag rating in full sun.  So, along with it and tracking, I'm trying to get a bigger bang for all those bucks 

[madlabs]

I am a tinkerer by nature and have always wanted to build a tracking array. Problem is it has just always seemed so much easier to add a couple of panels. I recently helped a friend implement single axis tracking on a 1.5kW array. It was fun, I had a great time because I wasn't spending the money. Didn't tempt me to do it at my place though.

Jonathan

[kenl]

   I have been doing the same mental gymnastics on this as you Watt, and every time I add up the dollars, I just
decide to put the money in more panels.  At $1 a watt,  the tracker you showed could buy me two more panels.
   Not saying I'm right, as experience may teach me otherwise, but that's how it looks to me right now.
  Good luck figuring out what's best for you.

I tend to agree with bj, the current cost of pv makes it cheaper to just add more watts to a system then add a tracker to increase solar harvast. Whem mppt controllers were very costly and pv was $4+ a watt trackers made more sense.

 Now if you like to weld and can get the metal for free or real cheap, or you have a lack of space to add more panels then a tracker might be the best option.

[bj]

  Did a re-read, and to clarify just a bit, I have no doubt trackers work, and are a great way to maximize.
  The mental gymnastics just said invest in panels now cause they are about as cheap as they can get.  In
fact, if Evergreen had kept their doors open, I doubt if they would be this cheap.
  Once you have enough panels for your needs, and have spare cash again, tracking is a logical step.
  Just my often flawed opinion though.

[Privatteer]

No Commercial links allowed in first post.

I've only done some basic testing of mine but the trackers in the store above appear to have a good rep. The light sensor does need weatherproofing. Apparently a glass jar works well.
I'm still trying to find enough time to mount the actuators and frame together in daylight.

In my case I am looking to maximize early and late production of a small system with a fairly constant load. Lack of room and battery storage means adding more panels is not as effective.

[tomw]

Watt (and others);

I accidentally moved this and then tried to move it back but might have put  it in a different board than it was originally in?

Coffee matters. 

Sorry for any confusion.

Tom

[Privatteer]

No Commercial links allowed in first post.

Oh well,
Anyway you can get tracker controllers for about $100-200 depending on required features.

Need to get home at a reasonable hour so I can cut the opposite side brackets for the actuator and then start on the frame for panels.
Pole is on its side, north/south actuator. Tec screws are only temp will be bolted properly.

[rossw]

you can get tracker controllers for about $100-200 depending on required features.

Having purchased commercial controllers for more and less than that, I've been totally unimpressed.
I've built my own, and been sent others to try.
They've worked.

In the end, I've gone back to time-based tracking.
It's ultimately more accurate more of the time.
Clear, cloudless days are a doddle to track. But most of the tracker controllers come unstuck under overcast conditions, or partially overcast, or overcast mornings, etc.
Probably my "ideal" controller will be time-of-day with "fine tune" sun-seeker.
I haven't built it yet

PS: I've been working on an entirely and hitherto unseen technique, which I feel will work particularly well. It's only been made practical by recent innovation in other not-immediately connected technologies. Once I get time and interest back and build one, I'll post the results - but I expect them to be "brilliant".

[ghurd]

@ Ross,
I think most places would be OK with single axis sun following tracking, if the speed was VERY slow.
Or maybe if a timer was implimented to only move/track a couple/few seconds per minute?


Back when I did a lot of small solar installs, when PVs were expensive and MPPT was all Smoke&Magic,
a brought a mini factory demo tracker to show me.

He explain this & that, talking fancy with multiple sylable words most people do not understand, and how it was German.

Then he sets it down with the little PV facing far away from where we would guess the sun is.
And he flips the switch.
The thing started tracking like a coffee'd-up jitterbug on an electric fence.

I guess nobody told him this is NE OHIO, and just south of the snow belt? (we get clouds even when its not cold enough to snow)

Actually I did tell him this is NE Ohio, near the snow belt, and it wouldn't do me much good compared to the cost around here.  I was trying to save him the drive from VA to demonstrate in person that his product would not do me much good.
He didn't believe me.
G-