Home built tracker

[Graham]

Small off grid system with tracker at island cottage, Lac-Simon Quebec.

Specifics:
2 - Kyocera KD250GX-LFB2 250W 20V Solar Panel in series,
Classic Lite + WhizBangJr Battery Monitor,
2 SPDs,
MNDC175 Mini 175 Amp DC Disconnect, MNPV3 Combiner Box
Samlex PST 1500W 24V Pure Sine Wave Inverter
4 8L16 6V batteries

The controller is overkill for this system but I wanted to be able to monitor the charge state with my android app.

More pictures at https://solartracker.codeplex.com/

[zoneblue]

VERY nice job on the tracker. I always wondered whether at atmel had enough floating point to do the math to calc solar position. Which algorithym do you use? When i did this in php on a ARM7 is was quite slow. And ARM actually possesses a FP unit.

One thing to note on the 500W /24v into a classic. Best you measure the idle/tare loss in that setup. You might find that it bites hard.

[Graham]

VERY nice job on the tracker. I always wondered whether at atmel had enough floating point to do the math to calc solar position. Which algorithym do you use? When i did this in php on a ARM7 is was quite slow. And ARM actually possesses a FP unit.

One thing to note on the 500W /24v into a classic. Best you measure the idle/tare loss in that setup. You might find that it bites hard.

I ported the code that calculates the sun azimuth and elevation from javascript to C#, the original javascript was used at the NOAA's Solar Calculator web site. The tracker only moves when it position is at least 5 degrees off the calculated azimuth, so it has lots of time for the math.

The cottage is only used from May to October, so I don't have to size the system for late fall...
The KID would have probably been better suited for this setup but since it doesn't yet have serial data access, I opted for the classic for now.