Author Topic: Tracker on the cheap  (Read 7078 times)

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Volvo farmer

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Tracker on the cheap
« on: March 06, 2006, 01:23:51 AM »
I bought two of these LED trackers from Duane at Redrok recently. Man, these are a nice pice of electronics to come out of an independant source. Here's the link if you haven't heard of these. <http://www.redrok.com/electron.htm#led3x target= blank> Tracker



So I've got this little 2x80W array out at my garage. I always knew I wanted to build a tracker so when I mounted the panels, I did it on an old satellite dish mount that I had welded a couple of bed frame rails on. I did learn that bed frames are hardened steel after I ruined a few drill bits. I finally installed the actuator last week.



Anyway, I went out today with some wire and a pickle jar and actually got this thing wired up and it appeared to be working. The array was significantly east of the sun when I started and this tracker only operates the actuator for a few seconds every minute. By the time I had to leave, it had almost caught up with the sun. I really wanted to wait around and watch it work but was out of time.



I screwed the pickle jar lid to a piece of 2x4 and drilled a hole through the lid for the wires to come through. The little electronic circuit was going to be tough to mount in a glass jar so I cut up some blue foam I had laying around and wedged and stuffed until it appeared to be firmly mounted in there. I then screwed the 2x4 to the top of the bed frame.



This tracker will park itself in the east after the sun goes down and Duane recommends using a separate battery for it's power. I had an old phone company AGM laying around so I used it. I have a 5W 12V amorphous panel I will hook to the battery soon to make up for the energy used to track the sun daily.



Old C band satellite dish and actuator - free

3" steel pole found in neighbors scrap pile - free

Bed frame found in alley - free

Telco AGM battery from buddy at Qwest -free

Assorted scraps of wire -free

Pickle jar -free (Mmmmm, kosher dills)

Redrok LED tracker $35



20% gain on 160w panels, five sun hours/day...160WHR/day.... Priceless!







 






« Last Edit: March 06, 2006, 01:23:51 AM by (unknown) »
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drdongle

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Re: Tracker on the cheap
« Reply #1 on: March 05, 2006, 06:28:40 PM »
Great Job!
« Last Edit: March 05, 2006, 06:28:40 PM by drdongle »

oztules

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Re: Tracker on the cheap
« Reply #2 on: March 06, 2006, 03:50:37 AM »
Nice addition to the place. 20% is a fair addition of solar cells, makes the $35 look insignificant. Well done .


Not everyone can find a bedframe  in the alley nowdays.


...........oztules

« Last Edit: March 06, 2006, 03:50:37 AM by oztules »
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BigBreaker

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Re: Tracker on the cheap
« Reply #3 on: March 06, 2006, 08:11:37 AM »
I had a similiar idea in mind for a tracker.  You might improve the mounting a bit by attaching the electronics to a small frame which is then fixed to the underside of the jar lid.  As long as the electonics package fits through the neck of the jar you should have a robust mounting.  You might also want to put some silica beads in the bottom of the jar to suck up moisture.


Anyone without a spare actuator should think about using all thread and a nut fixed in a gear.  A small motor turns the gear which turns the nut which produces a large linear force co-axial with the all thread.


An alternative to using the LEDs, batteries and a panel is to just use panels for the sensing directly and use their output to power the circuit and the actuator.

« Last Edit: March 06, 2006, 08:11:37 AM by BigBreaker »

BT Humble

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Re: Tracker on the cheap
« Reply #4 on: March 06, 2006, 07:14:10 PM »
I had a similiar idea in mind for a tracker.  You might improve the mounting a bit by attaching the electronics to a small frame which is then fixed to the underside of the jar lid.  As long as the electonics package fits through the neck of the jar you should have a robust mounting.  You might also want to put some silica beads in the bottom of the jar to suck up moisture.



I'd suggest putting the pickle jar the other way up (ie. lid pointing toward the ground).  That way water can't possibly drip down the wiring into the jar.


BTH

« Last Edit: March 06, 2006, 07:14:10 PM by BT Humble »

Volvo farmer

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Re: Tracker on the cheap
« Reply #5 on: March 06, 2006, 08:10:34 PM »
Yes, I agree and had the same idea. The mounting holes on the bedframe just didn't line up very well for that. What I really want is a nice plastic peanut butter jar, but we don't eat that kind of (hydrogenated) peanut butter so they're hard for me to find.


I like the idea of mounting the electronics to the lid, I'll try that next time. Maybe a big-ol-dab of silicone will keep the water out my jar for a while on this test rig.


I went out today and the panels were dead-on to the sun at about 10AM. What a cool device!

« Last Edit: March 06, 2006, 08:10:34 PM by Volvo farmer »
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wdyasq

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« Reply #6 on: March 06, 2006, 08:12:03 PM »
BTH,


That make far too much sense.


Ron

« Last Edit: March 06, 2006, 08:12:03 PM by wdyasq »
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amiklic1

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Re: Tracker on the cheap
« Reply #7 on: March 07, 2006, 08:23:07 AM »
I suppose you're using existing motors that came with your sattelite dish frame. I am planning of buying the same tracker, and I have some steppers and servos, but don't know how to hook them to the tracker. Is that hard to do? I got two 50W panels (homemade, working perfect).
« Last Edit: March 07, 2006, 08:23:07 AM by amiklic1 »

Volvo farmer

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Re: Tracker on the cheap
« Reply #8 on: March 07, 2006, 12:07:34 PM »
You need limit switches on each end of the travel and diodes so that you can pull the thing the other direction. There's a diagram of how it works on the Redrok site. If you can find a used satellite actuator, they have the limit switches built in. Are you in the US? There are old abandoned c-band dishes everywhere here. Everyone has gone to 18" dishes and I could have a dozen old dishes if I wanted them.
« Last Edit: March 07, 2006, 12:07:34 PM by Volvo farmer »
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amiklic1

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Re: Tracker on the cheap
« Reply #9 on: March 07, 2006, 04:09:04 PM »
No, I live in Croatia (Europe). Ihave a number of steppers from printers and photocopy machines. I think it can be used, with a kind of a gearing (some of them are geared). As I understand, it works so that tracker gives an impulse into the motor to move it into desired direction. When it comes to the limit position, the tracker gives a series of impulses to the motor, sao it moves the array into other position (east).

It's not complicated for me to build the axis and the frames. Where to find limit switches? Is it some ordinary switch (I have plenty of them, all kinds of microswitches etc)?
« Last Edit: March 07, 2006, 04:09:04 PM by amiklic1 »

Volvo farmer

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Re: Tracker on the cheap
« Reply #10 on: March 07, 2006, 04:51:52 PM »
Yes, ordinary switches, like are used in the doors of microwave ovens. Like these

http://www.electronix.com/catalog/images/47-499.jpg

Yes you need a limit in the eastmost and westmost positions, otherwise the tracker will continue to move west or east past the phsical limits of your moving apparatus.
« Last Edit: March 07, 2006, 04:51:52 PM by Volvo farmer »
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ghurd

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Re: Tracker on the cheap
« Reply #11 on: March 07, 2006, 05:28:25 PM »
I would like to know the real gain if you keep track of it that close.

The 20% is a lot less than I would expect. Sounds more like the number for MPPT tracker than this kind of tracker.  Seems like someone (Tom? W? in NH?) figured on ~40%?


Any thoughts on solar heating of the jar?  Maybe some silver Al tape for reflecting the heat away, where it won't bother the operation.


High temp hot glue seals about anything.


Great job! Looking forward to hearing how it works.

G-

« Last Edit: March 07, 2006, 05:28:25 PM by ghurd »
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Volvo farmer

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Re: Tracker on the cheap
« Reply #12 on: March 07, 2006, 06:33:45 PM »
20% was a number I pulled out of the air based on some things I've heard. I don't know that I'll ever be able to measure the true difference. These batteries just sit there on float 95% of the time and I have no device for measuring my amps in/out on this little system.


I'm preparing to fly a 680 watt array with a similar setup. It might be possible in a year or so for me to compare fixed vs. tracked on the bigger system but it won't be for quite a while.


I haven't thought much about heat in the jar. Hmmm, maybe I should. The nice thing is if I burn the tracker up, it's only a $35 lesson.


I was out yesterday and today and the thing was pointed exactly at the sun every time I looked at it. It works flawlessly so far. Maybe I'll disable it for a while since I'm not using a single watt of that electricity I'm making.


Now I'm dreaming on how I could use the heat from a solar concentrator. I've got two very nice eight foot aluminum dishes laying around here.

« Last Edit: March 07, 2006, 06:33:45 PM by Volvo farmer »
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ghurd

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Re: Tracker on the cheap
« Reply #13 on: March 07, 2006, 07:15:59 PM »
The 20% seems low for what I read.  Never did it.  And couldn't measure it either.

Not sure about the heat build up.


"not using a single watt"


Maybe Ed's style simple shunt to a dump heater?

Like 160W, x 5 hours, x 150%.  Thats like a space heater for 1 hour a day.


Maybe a 12V CFL or 2 from a single wire from the batteries?

In the most used lamps in the house.


Maybe charge the cell phones, LED lights, and drill batteries?  

Thats mostly what I do with my wind power.  :-/

Feels nice just the same.


G-

« Last Edit: March 07, 2006, 07:15:59 PM by ghurd »
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GaryGary

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Re: Tracker on the cheap
« Reply #14 on: March 08, 2006, 08:03:29 AM »
Hi,


Nice Job!


You can look up the gain for tracking here:

http://rredc.nrel.gov/solar/pubs/redbook/

Just download the data for your state, and lookup the difference between "Flat plate Facing South" and "1-Axis Tracking".


For Albuquerque, NM its:



  1. 4 KWH/sqm - day for no tracking
  2. 5 KWH/sqm - day for 1 axis tracking
  3. 5/6.4 = 1.33 or 33% gain.


Its probably a bit less in areas that are more cloudy.


Gary

« Last Edit: March 08, 2006, 08:03:29 AM by GaryGary »

Volvo farmer

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Re: Tracker on the cheap
« Reply #15 on: March 08, 2006, 08:39:20 AM »
Thanks, Great info there!
« Last Edit: March 08, 2006, 08:39:20 AM by Volvo farmer »
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GaryGary

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Re: Tracker on the cheap
« Reply #16 on: March 10, 2006, 06:34:26 PM »
Hi,


Hope you don't mind -- I put a copy of your post on the cheap tracker here on my website: http://www.builditsolar.com/Projects/PV/pv.htm#Tracking


If you would rather not have it there, just let me know and I'll remove it.

I try to pick up good projects that people can build, and this tracker you did seems like a really good one.


Gary

« Last Edit: March 10, 2006, 06:34:26 PM by GaryGary »

janee

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Re: Tracker on the cheap
« Reply #17 on: January 06, 2008, 02:58:01 PM »
hi just want to ask on how you made your own pv cells?? coz i really want to try making my own.. tnx
« Last Edit: January 06, 2008, 02:58:01 PM by janee »

Volvo farmer

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Re: Tracker on the cheap
« Reply #18 on: January 06, 2008, 06:26:13 PM »
I did not make my own solar CELLS. I bought cells and made them into panels.


http://www.fieldlines.com/story/2005/2/26/11119/5985

http://www.fieldlines.com/story/2006/9/12/05630/1438

http://www.fieldlines.com/story/2006/9/16/05931/0581


What I thought would be a 100 watt panel puts about 2.5A into a battery at 25V. So more like 60W. I think I'd do better with 38 or 40 cell strings as my VOC seems a little low.


I bought these cells super cheap. Probably have less than $500 into 250W of solar. Unless you can get your cells for about $1/watt I do not think an enterprise such as I have undertaken would be financially viable.

« Last Edit: January 06, 2008, 06:26:13 PM by Volvo farmer »
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