Tracker vs fixed.

[Brian Spilsbury]

The data seems to be a slam dunk in favour of a 2-axis tracker. Up to 30% more energy captured compared to fixed PV but maybe not????

My Deger 5000 trackers have ghosts though. For no reason, they will both lose the sun fix and start hunting. After 20-40 minutes they get a new lock but in the mean time, output drops from 10kW down to close to 5 during the interim.

Is this confusion because of light bounce off the snow?

[Dan Lenox]

Brian,

The biggest bang for the buck (IMHO) is single axis. You can get 30% more output with it over a fixed array.

Obviously a dual axis you can expect slightly more.

But if you make your tracker so that the declination can be adjusted manually then the single axis stepper is pretty close to the dual axis. Adjust the angle 2-3 times a year and you're good to go. I use this method myself.

Dan Lenox

[Dan Lenox]

Brian,

Sorry did not read the end of the post.

I'm assuming that the 5000 is an active control, have you looked to see if you are getting some reflection 'ghosts'.

Easiest way to check is do a visual verification that the array is tracking properly. Reflections from either enclosure or external surfaces can sometimes fool the tracker.

Dan Lenox

[Brian Spilsbury]

Dan, I think the difference between single and dual axis is only 5%.

The Deger techs have been watching the system today as it kicks in and out and have determined it's the wind sensor that's causing the problem. A gust causes the units to go into protect mode, meaning they flatten out for 10 minutes of below threshold speed time.
Right now, there is so much snow bounce, in tabletop configuration the sun sensor is being blinded by the reflection of the snow, so thinks the sun is "down there".