Calculating mismatch in trackers with different axis tilts

[Bruno Lima]

Hello,

 

We are doing a project where the trackers in the field are having small discrepancies in the axis tilt (varying from -3.3º to +3º). Since they will all be conected on a single MPPT, our client asked us to calculate the mismatch loss that this will cause.

 

Is it possible to do so in PVSyst? I tried to, but only saw the possibility of having one orientation for trackers (unlike in fixed tilt where i can have several orientations).

 

Thanks

[Michele Oliosi]

Hi Bruno,

No, for trackers we perform the transposition using only a single orientation value. There may be a way to compute this mismatch in some future update of PVsyst, but for now it would be quite difficult.

You may get a rough estimate of the mismatch by using the fixed tilt option, but it probably requires to be quite careful.

[Bruno Lima]

Hello Michele,

 

Thanks for the return.

 

I´m trying to simulate on a fixed tilt, defined 7 orientations, but I´m not being able to attach them all to the same inverter (in order to calculate the mismatch).

 

From other forum posts, I saw that I should use the Mixed #1 and #2 to that, but in this case it will only select two different orientations? 

 

The difference in the tilt is varying from 3° to -3°, so maybe If I use these two values I´ll be calculating the worst case scenario?

 

Thanks

[Michele Oliosi]

Yes the "mixed orientation" option can be used with two orientations only.

In the system window you can put them on the same inverter only if you put them on separate MPPT inputs. If not, then yes I would suggest to reduce the number of orientations to 2. Indeed, it may give a rough approximation of your output. You can also create the tables first, and then use the "orientation management" tool of the 3D scene. This will allow you to detect orientations automatically, with different tolerances. If you bring them down to two there, you may keep your 3D scene as is.