ThomasP

Let me clarify my question. The real world system has trackers following a backtracking strategy calculated based on only the location of the solar farm, the time, date and the inter-row pitch (i.e. the terrain is assumed to be flat). Therefore, this is the same backtracking movement modelled in PVsyst. The real world system however is not on a perfectly flat terrain. For a tracking system follow the above backtracking strategy this would result in a greater shading loss than what is modelled for a flat terrain. How can this extra shading loss be simulated in PVsyst? Can "Tracking fields" that cast shadows and placed at different elevations simulate this additional shading loss that is a result of the terrain not being flat?

The real world system that is to be modelled consists of trackers at different elevations due to the slight variations in the topography of the terrain. The trackers will be following a back-tracking strategy that assumes that the terrain is perfectly flat. To model this is in PVsyst: 1) A "Ground object" has been imported into the PVsyst shading scene from Helios based on the site survey. 2) Trackers have been grouped into "Tracking fields" consisting of 2 or 3 trackers. 3) Each "Tracking field" has been placed at different elevations depending on the elevation of the terrain under this "Tracking field". 4) Back-tracking has been enabled on all "Tracking fields". 5) Both the "Ground object" and "Tracking fields" have been defined to cast shadows. 6) The shading loss calculation is defined to be calculated according to the module layout. In the specific case where the real world system is following a back-tracking algorithm that assumes the terrain to be flat would the above approach be suitable?

Does anyone have any suggestions for this?

I'm trying to use Solmetric SunEye to measure the horizon for use in PVsyst far-shading analysis. The system I'm modelling is a single axis tracking system so what tilt should the horizon be measured at? I'm in Australia so should I just make the measurements by facing the camera north with a tilt angle of 90 degrees? Thanks, Tom

If degradation is included in the simulation so as to calculate the output for a specific year should the LID loss factor be set to 0% since the Year 0 warranted output as defined in the "Ageing" tab already includes LID losses. I.e. Will LID losses be counted twice if defined in the "Module quality - LID - Mismatch" tab if degradation is included?

- How do I convert the coefficients, a and b, used in the Sandia thermal model to the U-values used in the PVsyst thermal balance model? Regarding the thermal balance equation: U · (Tcell - Tamb) = Alpha · Ginc · (1 - Effic): - Are U, Tamb, Alpha and Ginc the inputs of the above equation and Tcell and Effic are determined so as to satisfy the above equation? - In a previous post in this forum it was stated that U has a high uncertainty. How is this uncertainty implemented in the above equation? i.e. what is the relationship between the U used in the above equation and the U-values defined by the user. Thanks for your help!

I have two questions regarding this tool: 1) I have uncertainty data for different PV component losses like LID, mismatch losses, efficiency etc. How do I combine them into a single uncertainty for 'PV module models and parameters' in the PVsyst P50-P90 tool? 2) In the FAQ section it mentions that the different uncertainties are added together quadratically. What is the equation? Since the production is more sensitive to certain inputs like Meteo data than others I assume there is different weighting given to different uncertainties i.e. soiling, inverters, PV components etc.

I had a question about the detailed computation of DC ohmic losses. The average lengths per circuit for 1) string module connections, 2) connections to main box and 3) main box to inverter are required. My understanding of the relevant cabling lengths associated with each of these circuits is as follows: 1) String module connections: length of cabling along a string plus the average cabling length from the positive pole of a string to a combiner box plus the average cabling length from the negative pole of a string to a combiner box. 2) Connections to main box: average cabling length from the positive terminal of a combiner box to a main box plus the average cabling length from the negative terminal of a combiner box to a main box. 3) Main box to inverter: average cabling length from the positive terminal of a main box to the inverter plus the average cabling length from the the negative terminal of a main box to an inverter. Is this correct?

I'm using PVsyst V6.62. The system is a single axis tracking system with backtracking. I'm using tilted axis tracking planes with multiple rows. I want to use misalign so that the trackers follow the angle of the plot boundaries. Only a negative pitch ( -6 m) gives the correct tracker misalignment that matches the plot boundary (PVsyst does not seem to allow a negative misalign value to be used in order to change the direction of misalignment). Specifying a negative pitch however leads to the following error"...the pitch between trackers is too low" and hence the shading factor tables can't be calculated for this system. How can I specify tracker misalignment in the opposite direction of the default misalignment direction?

I use the near shading tool to make layouts on top of imported Google maps to show customers/clients what the proposed PV system would look like. Is there any way to make the PV planes looks realistic and more like real solar panels i.e. instead of only being a single color, is it possible to display simple patterns on the PV planes? Many thanks, Thomas

I can't position modules on "tracking PV planes" in the module layout page. For "rectangular PV planes" and "PV tables as sheds" the module layout page works as expected. Is this a bug or is the module layout functionality not supported for "tracking PV planes"? Many thanks!

Is there someone who could answer this question for me please?

So the altitude for all the sub-fields is the same. The pitch is also constant both within sub-fields and between sub-fields. The collector width is also constant throughout the system. The shape of the land is not a rectangle so many rectangular shaped sub-fields of different sizes have been used to utilise all the land. My question was how does the PVsyst backtracking algorithm handle the mutual shading between adjacent sub-fields in this case? Is this system one that the back-tracking algorithm could accurately model? Many thanks! Thomas

I'm designing a system with backtracking (horizontal axis tracking and no tilt) however the shape of the land is such that I have to use many sub-fields in order to make efficient use of the available land area. Throughout the system the pitch between all trackers is uniform and so is the collector width. For such a uniform system in which backtracking is defined for multiple sub fields how do the backtracking calculations work? Are the shading effects between sub fields taken into consideration or is each sub field considered independently and then the performance of the system is some combination of the performance of these individual sub fields? Many thanks!