Janani

Hi, We have actual measured GHI data from site and actual tracker gain obtained from it. When the same GHI data was imported in PVsyst, it showed a higher tracker gain than the measured. We understand that one reason is the diffused content variation between actual & estimated which affects tracker gain. The differences are tabulated below. Actual at site PVsyst Prediction for the same GHI Month GHI (kWh/m2/d) Tilt radiation (kWh/m2/d) Radiation gain on tracker plane (%) Tilt radiation (kWh/m2/d) Radiation gain on tracker plane (%) Jan 5.23 6.15 17.59% 6.55 25.15% Feb 5.49 6.46 17.67% 6.79 23.60% Mar 6.31 7.27 15.21% 7.88 24.84% Apr 6.19 7.03 13.57% 7.60 22.78% May 5.97 6.84 14.57% 7.23 21.04% Jun 5.35 6.05 13.08% 6.36 18.94% Jul 4.7 5.19 10.43% 5.55 17.98% Aug 4.27 4.65 8.90% 5.04 18.08% Pl clarify whether PVsyst team has done any comparison of actual gain vs PVsyst estimation for trackers and has done any validation of the inbuilt tracking algorithm . Pl note, the parameters such as tracking angle, pitch and orientation were maintained same as per site condition Thank You

Hi, Pl explain the difference between the following parameters under “custom table” option in detailed results tab Tarray – Average module temperature during running TArrWtd – Module temperature weighted by Globinc Both includes incident radiation effect right? Thank you

Noted. Kindly request PVsyst to include snow loading effect in energy estimation with the input of snowfall pattern and snow depth. Thank You

ok. But it is seasonal. Hence is there any PVsyst's recommendation on how much % loss to be considered for snow cover?

Hi, I am estimating generation for a region near Himalayas in India. as the location is prone to snow fall, pl let me know how to account loss due to snow loading on PV modules. Should it be factored in soiling?.. Pl help. Thank you

Hi, can you pl provide a diagrammatic representation of what is the meaning of profile angle in PVsyst. Thank You

Hi, I am working on a project of 600MWp and currently performed a simulation in PVsyst v 6.78. this project required grid injection power to limited to xMW @0.928 leading pf. Same has been incorporated in the available feature of PVsyst and a sample hourly data from .csv file for one day is provided below. As Per PVsyst .csv file Timec E_Grid EApGrid EReGrid W kVAh kVAh 07:00 22364995 24096 8968.4 08:00 2.19E+08 236112 87879 09:00 3.93E+08 423580 157653 10:00 3.76E+08 404983 150731 11:00 3.5E+08 377463 140488 12:00 3.35E+08 361452 134529 13:00 3.44E+08 370845 138025 14:00 3.57E+08 384763 143205 15:00 3.43E+08 369665 137586 16:00 1.34E+08 144761 53879 If I calculate the apparent power & reactive power manually, there is a mismatch between calculated value & PVsyst simulated value. Pl find below the calculated values of the same. From PVsyst Calculated value Time E_Grid EApGrid EReGrid W kVAh kVAh 07:00 22364995 24100.21 8965.278 08:00 219148490 236151.4 87848.32 09:00 393148430 423651.3 157598.3 10:00 375887535 405051.2 150679.1 11:00 350344222 377526.1 140439.7 12:00 335483790 361512.7 134482.7 13:00 344202008 370907.3 137977.5 14:00 357120146 384827.7 143155.9 15:00 343106886 369727.2 137538.5 16:00 134360623 144785.2 53860.08 Pl help in bridging this mismatch. Thank You.

hi.. How to estimate PV generation from bifacial Fixed tilt system with reflectors fitted to Module mounting structures. kindly let us know with the available features in PVsyst v 6.78. Thank You

Hi.. I am trying to simulate a bifacial system on a rooftop top surface. Pl let me know, the albedo which we are entring shall be applied to ground surface or the rooftop surface? Thank You.

Hi, In PVsyst 6.47, there is a column in inverter .OND file namely Output parameters, which has the provision for allowing inverter to inject overpower than rated at low temperature conditions. Kindly clarify, the variation of output power w.r.t temperature is calculated considering ambient temperature or inverter operating temperature. Thanks, Janani

Hi, Is there any possibility to extract minute-wise generation data in the form of .csv file from PVsyst similar to hourly values in currently available PVsyst versions. Thanks, Janani.K

Net gain estimation using PVsyst for HSAT I had done HSAT simulation for the location Veltoor in Telangana –India. The coordinates of the location are 16.443° N, 77.865° E. HSAT Specifications are as below: Axis Tilt 0° Pitch 4m Axis azimuth 0° (South) Collector bandwidth 2m Tracking range -45° to +45° Following are the net gain estimations using PVsyst v 6.38 for this location. Parameters With Shading scene Without Shading scene With Backtracking Without Backtracking With Backtracking Without Backtracking Gain over GHI 22.6% 27.0% 22.6% 27.0% Near shadings: Irradiance level loss 2.6% 5.7% 0% 0% IAM loss 1.9% 1.7% 2.2% 2.0% Shadings: Electrical loss 0% 5.2% 0% 0% Net gain 18.1% 14.4% 20.4% 25.0% In the attached comparison, GCR is 48.9%, axis tilt is 0°and number of trackers are 120 which are maintained same in all four cases. In the attached comparison, the net gain calculated after deducting shadings due to irradiance level loss, IAM loss and Shadings: Electrical loss are different in all four cases. Based on your previous reply, does that mean generation estimation for HSAT option using PVsyst without shading scene is invalid Please let us know, from the attached comparison, which option is more reliable and correct.

Hi, Thanks for your reply. can u please let us know, in PVsyst, when we simulate single-axis east west tracker without shading scene , why shading loss is not accounted, whereas in fixed tilt simulation, shading loss is accounted by PVsyst even without shading scene (with unlimited sheds option).

Hi, I have done a comparison on gain over tracker plane radiation for a horizontal single axis east-west tracker between 'with back tracking' and 'without back tracking'. in the case of 'with back tracking', the radiation gain on collector plane is 18.3% over Global Horizontal Irradiation(GHI) and for the case of 'without backtracking', gain is 27.7% over GHI. As per PVsyst report, the Near shading loss for 'without backtracking' case is 9.9%, out of which 5.6% accounts to beam loss and the rest to diffuse and albedo. Similarly for 'with backtracking' case, the Near shading loss is 3% which is due to diffuse and albedo (almost same as 'without backtracking' case). My question is , if shading due to beam component is adjusted in 'with backtracking' case, the net gain on collector plane over GHI should be (27.7-5.6) equal to around 22%, but PVsyst report shows only 18.3% gain over GHI. Kindly clarify which parameter makes the difference in gain on collector plane over GHI between 'with back tracking' and 'without backtracking'.