Solar Tracker Project

ok Xringer
just needed a plan for testing
in my page you'll see related structures

[Xringer]

That's one nice looking X-Y tracker. But with one small panel, I assume it's mostly for demonstrating tracker technology.
It looks like you tested a bunch of different optical modules.
That real long one might be a little over-kill. You don't need .01 degree accuracy for this application.

I just skimmed the circuit diagram of your controller, and it looks more original then some I've seen.
Is there any hysteresis action on those Op-amp comparators?

[Xringer]

It's been raining here, so it's a good time to work out the tracker bugs.
My fancy waterproof tracker module case (made from an outdoor flood light), isn't working at 100%.
It's off target early in the morning, perfect at mid-day and then wandering around in the PM..
It's not a lot of error, just enough to be irritating..

The RedRock board is just too deep inside the case. It can't see the sun off to the side.
I think the sensor diodes are pointing at the edges of the case. Not getting the light it could be getting inside a Jar..


After cleaning out a peanut butter jar and thinking about it, I found this Gas tight lamp at Home Depot..



Took out the socket and wires, mounted a 1/8" slab of G10 to hold the RedRock board.


Cut some of the bars out, painted the rest black and I'm ready to install the Red Rock tracker board!

I call this the Fancy Version of a peanut butter jar..


The wiring box will be on top, with the glass pointing down and south.
Sunlight should hit the sensor diodes, no matter when the sky clears up.
Unless it's really dark until well after noon, it should never fail to track.

I've noticed it will track when it's overcast, trying to center up on the brightest part of the sky..
So, if it's cloudy all morning, there is a real good chance the RedRock will have moved the array near the Noon posistion.
Once in the Noon posistion, the second the sky clears, the tracker will sun seek. Because, it will have a clear Horizon-to-Horizon view of the sun's track..


I have a feeling there will be a lot of heat.. I may wrap the glass in silver tape,
leaving an open strip around the center, exposing the sensor diodes..

To keep light from bouncing around inside, maybe black paper under the tape.. Inside the glass.?.


If it will only stop raining!!

[Daox]

Nice find on the lamp. That should prove a bit nicer than a peanut butter jar.

[Xringer]

No one can say that I'm not a die-hard-hacker now! I was just out in the rain,
installing the RedRock-Under-Glass..



Good test to see if it's water resistant.. Once installed, it immediately started tracking west in small increment.

It's looking for the brightest part of the sky. It stopped in the 2PM sun posistion. (It's now 4PM).
Since it's raining pretty good now, it's impossible for me to tell where the sun is now.
I think the reason it's just sitting there now, is both sensors are seeing the same brightness in the East & West cloud cover.

I believe the reason it moved in the first place, is because the East sensor diode was looking at the big trees next door (to the east).
That was an imbalance in the sensors, corrected by moving the array west.

So far it's looking good. The forecast is Partly Sunny for tomorrow..
I guess we are going to see if there is any proof in the pudding..

[Daox]

Haha, nice job. Glad to see it works well even on cloud covered days.

[Xringer]

It looks like the heat sink compound under the resistors seeped down
the mounting screws and into the epoxy and caused it to fail.
The heater stopped making good contact with the boiler's top surface.

For now, I'm going to block off the coal-wood burning side of the boiler, to keep
the dust & etc from the oil burner contained, and try heating the cold floor of the
boiler and the air inside the ash clean-out compartment..


The power will come in via the air-intake vent, and I'll pack insulation around the cable to keep heat losses low.

I think this might work better than the top-side heater.. Since the hot air is pretty much trapped in this compartment.
The coal grate (above the resistor bank) is covered with sheet metal, with 30 pounds of scrap iron on top of it.

I think that a fairly high percentage of the heat from the load is going to be absorbed into the water-jacket walls.

A big clean up job.. This the cleanest the solid fuel side has been in about 30 years!!

[Dave]

H all,
Just joined today. Been doing research on solar. Bought 3K worth of cells (700, 6x6 mono)
Hope to document progress. Anyway, came across this guy who used the same housing. Thought you might be interested.

"So to resolve this situation I spray painted the inside of the glass (but not the very end of the dome) with some blue paint that I had laying around.
This completely fixed the tracking mis-alignment and now it very accurately is tracking the sun."

briery dot com/solar/solar_tracker.html

[Xringer]

Thanks Dave.. Now I see that I wasn't the first to think of a better looking peanut butter jar..

It's a very similar light fixture. But his RedRock has remoted sensor diodes.
My LEDs are on the board, looking up. (standard is looking off the end).


Dan Lenox's Solar Build - Solar Tracker



His sensors are looking at the world through a spherical glass dome.
A dome with a large seam in the center of it. You can see some distortion in the pic.
Mine has the same seam and looking through mine revealed a flawed fish-eye effect..

The guys who use jars, have learned to avoid using the bottom of the jar,
they aim the LEDs at the side of jar, for Less distortion.


The side-view design is what I tried to copy for my tracker unit.
It gives the most visibility of sun's track, with the least distortion possible.

I've heard that thin plastic peanut butter jars are the best optically,
but I wanted to use glass.. Since I think it's going to last a lot longer.

[Xringer]

Originally Posted by Daox

Haha, nice job. Glad to see it works well even on cloud covered days.

It's still raining and getting a lot darker out now. I was just outside cleaning
some paint bushes for my wife. Had to stop and watch the array very slowly tracking over to the east..
A tiny red LED on top of board (back near the connector) lights up when it's moving.
It's just moving a few mm and then resting. I don't know, but it seems like it takes hours to get to the Home posistion..