The installation went smoothly once freed from the hoops of the permit cycle. It took a couple month to deal with the 30+ year old 2500 sq ft shed which was holding up the solar permit - no record of a building permit. So much for streamlining the process
The only hitch, in doing the actual work, was working around the weather. Working with a few raindrops wasn't a problem, but the muddy situation was a problem - as we were working off a platform mounted on our tractors pallet forks. The Wattsun trackers work well, as long as there is some sun to track. I found a few interesting situations on cloudy days. There were times when the trackers wouldn't progress during the days. Power output was unchanged when I manually positioned to where I thought the sun was located. One time, I saw both panels flat (in the horizontal position) - reminded me of the search for intelligent life - ET come home . For the most part, the Xantrex GT 5.0, power output has stayed below 3.6K, but I noticed power output around 4.5K during a time when the sun shone through an opening in the clouds - I'm guessing the scatter off the clouds added to the direct sun light to made it much higher. The only thing that was a bit surprising was the peak power during the "cloudless" days wasn't higher than 3.6K. I'm running with 24 Evergreen 180's I bought from Sun Electric (seconds). Is this reasonable during this time of year?

Thanks again to all who gave guidance on our first solar project!

I have the Wattsun Tracker as well. I do not think you can expect the tracker to track the sun through the clouds, at least mine will not. As soon the sun comes through the clouds bright, the tracker finds the sun. When there is no sun, often not always, the tracker will flatten itself, I assume that it is trying to find the sun and cannot. This event of flattening does sometimes come in handy as wind often picks-up and the flattened unit has less wind resistance.
I am glad to hear that all is working well for you.

I'm on Long Island, NY @ 40 degrees N lat. I have 36 Evergreen 190s w/ an SMA SB7000US and no tracker.(rated max=6840w) My roof and panels are at a 3/12 pitch. Right now the sun is out and I'm producing 5.35kw. My highest peak was 6.34kw and my highest daily output was yesterday @22.91kwh. If my summer peaks are much higher than the winter I may pitch the array to 40 degrees this fall.

I figured it wasn't a problem with the tracker, but rather with the situation - I was guessing the energy distribution (with all the scatter) is pretty even in all directions - plus there doesn't appear to be much energy potential to capture. I found it revealing to be able to scan different azimuth/elevations to see what was "out there".
Thanks for the feedback.

Thanks for the feedback - how long have you had the system running? I'm still trying to make sense of the numbers, so seeing your numbers helps. The rebate program we've applied for is based on actual production for a 5 year period - I want to make sure all is ok before the "rebate clock" starts.
Our production has been all over the map during the 10 days of operation. The first day it was 32KW, dropped to 30 KW the next day (both days were cloudless). I found that a bit curious, but imagine my perception, that both days were equivilant, was most likely wrong. Then followed days with different degrees of clouds - 5KW through 17KW.

I started my system on Dec. 21, 2007. Today I produced 24.14 kwh, a new record. You must be down south somewhere because your system is rated at 4320 watts, 2/3 of mine. Yet you put out 50% more than mine. I'd say your doing fine.

I had the same thought. My system is 27 Sunpower 205's, it has been on line since the middle of Nov, 2007. The highest I have seen so far is about 4000W continuous, some spikes up to about 4900W on cloudy day.

I just recorded 24kw-h last week, a record for me (it had been in the 18-21 range). My orientation is not optimum, but even still I'd say for your hardware you are getting superb output.

Thanks for the additional info - We're at 37 N latitude, so that would explain some of the difference - From the data I saw on PVWatt the trackers should give an additional 40%, which most likely explains the rest. I just checked my log, and my memory is failing me a bit. I placed the trackers in manual mode on the second day (e.g., between the first two auto tracking days). So, the second day I had the system running I set the tracker to 190 degrees with a 21 degree tilt and left it in manual mode. This would have been the orientation I would have gone with if I went with a fixed system. The third day was back to auto. The first full day of production was on 2/14/08. Below are the numbers I recorded off of the Xantrex for the first three days.

Total Production 2/14/08 – With tracker in auto and no clouds in skies 33.58 KW generated
Total Production 2/15/08 – With tracker in Manual and no clouds in skies 23.3 KW generated
Total Production 2/16/08 – With tracker in auto and no clouds in skies 30.1 KW generated.

I thought the following was interesting to see:
On 2/15 I flipped the tracker back to auto with ~ 20 minutes of daylight left.
Time.........Accum power.....Power Level(Rate)......Tracker Mode.....Comments
5:05.........23,031...................349..........................Manual
5:10.........23,040...................964..........................Flipped to auto............By the time I got back to take a reading the tracker had repositioned to around 225 degrees.
5:13.........23,125..................1316........................Auto tracker still moving West
5:14.........23,148..................1663........................Auto Tracker Adjusted Tilt
5:32.........23,315....................312.........................Auto Sun went down

congrats on the successful install of your system. I am looking forward to my install next month!

I am surprised that the trackers haven't integrated GPS receivers into them that can point to the sun's position every day whether it's clear or not. (we do know where the sun is going to be every day for some time!)

Maybe I've spilled my secret plan to get rich but I'm shocked someone hasn't already mechanized what I've summarized above...

Originally, I had a similar thought - at least, they could have improved on the positioning when there wasn't significant difference in solar energy for the tracker to "lock" on to.
There were a half dozen different times I went out and played around with repositioning the trackers when it was obviously pointing in what looked to be a bizarre location. During those times, repositioning the trackers to the "correct" location, it either didn't improve the power production, or it in fact lowered the output. It seemed there were two different situations going on -
the first, the tracker stays in the last position where it "saw" the sun, or
secondly, it moved to some unusual position - what I've noticed, was the tracker would be pointing more horizontal than the time of year dictates. Moving the tracker off of the nearly horizontal position turned out to decrease the output.
Prior to playing around with the trackers on these cloudy days I had thought it would be fairly easy to design a controller that stored the last known good position for each minute of the day - and if the sensor didn't "see" the sun then it would pick up the position in memory. But, it looks like the sensor isn't looking for the sun, but is rather "centering" on the maximum light - It's easy to know where it should be positioned when the sun is not obstructed. When it is blocked by clouds, it's not so obvious to my eye. I could believe the trackers sensor could see the center of the scatter, and this point might not be anywhere close to the sun. Anyway, when it's cloudy enough that it can't detect the sun, it doesn't seem to matter where the arrays are pointed.

The biggest confusion for me was the decrease in power between the first two days in auto tracking mode. Day three was longer than day one, and looked equally as clear and sunny - I'll just chalk it up to the solar panels are better at judging clear skies than my eye.