Solar tracking diy?

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.

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.

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.

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)

Re: Solar tracking diy?

konstantin.neo wrote: »

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.

Re: Solar tracking diy?

Volvo Farmer wrote: »

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

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