Annual yield simulation

11.7 Annual yield simulation

Click the "Annual yield simulation" button to enter the interface for the result settings. This interface is divided into four modules: "Type" (red box), "Output file" (blue box), "Main results" (green box), and "Table/Report" (yellow box).

11.7.1 Calculation type

When calculating the 8760 hour power generation, users can choose the type of "By array group". This mode allows grouping the real tilt and azimuth angles of all arrays according to the users set "Group tolerance", and calculating the average of the real tilt and azimuth for each group. Subsequently, based on these average values, the software will calculate the radiation received by the array on the inclined surface.

Users can also choose "Order reverse (pvsyst>=7.3)" or "Oreder (pvsyst

11.7.2 Output file

After completing 8760 hours of power generation statistics, users can decide whether to export these data to an Excel table. If users decide to export, please check the checkbox next to the "Output file" option.

Users can also choose whether to export loss calculation values, meteorological data, and power generation calculation values within 8760 hours according to their needs. If users need to export these data, please check the checkbox next to the corresponding parameter.

Users can export 8760 hours of data as follows: "Time", "g_hor", "d_hor", "temperature", "g_til"t, "hor_shading_loss", "near_shading_loss", "iam_loss", "soiling_loss", "reflect_on_back", "beam_to_back", "dif_to_back", "reflect_on_front, array_input", "module_degradation_loss", l"ow_radiance_loss", "temperature_loss", "array_output", "elec_loss_accs", "module_quality_loss", "lid_loss", "mismatch_loss", "dc_loss", "inverter_input", "inverter_output", "inverter_efficiency_loss", "hour inverter power threshold loss", "hour inverter power over loss", "low_ac_loss", "mv_trfs_in", "mv_trfs_loss", "mv_trfs_out", "mv_ac_loss", "hv trfs in", "hv trfs_loss", "hv_trfs_out", "hv_ac_loss", "unavailability_loss" and "hour_yield".

After completing the above two settings, the users can click the "Simulate" button, and the software will automatically calculate 8760 hours of yield. If the project scale is large, the calculation time of the software may be correspondingly extended (usually not exceeding 1 hour). Therefore, it is recommended that users save the current model before starting the calculation.

11.7.3 Main results

After completing the 8760 hour power generation calculation, the software will display the main calculation results in the yellow box area, including "Yaer yield", "Aunal equivalent hour", and "PR of yera".

Tips： The "PR of year" in the software is consistent with the definition of PR in PVsyst software, which means system efficiency, also known as system performance ratio, is an important indicator used to evaluate the power generation capacity of PV power system. The formula is: Among them, the "Peak sunshine hours" are the total radiation global inclined of the PV array divided by the standard light intensity Gstc under STC (1000W/m ²). Unlike the definition of the comprehensive efficiency coefficient K in the GB50797-2012 for PV power system, the total radiation on the array surface is used in the calculation of PR, while the comprehensive efficiency coefficient K uses the radiation on the horizontal surface. Therefore, the following formula will be obtained:

11.7.4 Table/Report

After completing the power generation simulation, users will be able to view the "Monthly yield" and "Monthly PR", and export the "Typical Day" output table and power generation simulation report.

"Monthly yield": Click the corresponding button to view the detailed electricity generation table output by the model for each month.

"Monthly PR": After clicking the button, users can view the detailed PR table of the system for each month.

"Typical Day": After clicking the button, users can browse the typical monthly power generation data of the system. In the table, the horizontal axis represents time periods, while the vertical axis represents months.

"Report": After clicking the button, a power generation report can be generated. The report mainly includes the sections such as "Project Overview", "Solar Resources", "Overall System Plan", "Power Generation Calculation Settings", and "Power Generation Calculation Results".

11.7.5 Calculation values and related setting parameters of loss diagram

When calculating power generation, the software performs the following three key steps:

1. Firstly, based on the layout of the array in the model and the "Group tolerance" set by the users, the software calculated the amount of solar radiation received by the front of the array. During this process, the software takes into account the actual condition of the model and calculates the radiation loss caused by shadings, known as the "Near shading loss";

2. Secondly, the software will calculate the gain of back radiation (if any) and evaluate the related losses of back radiation based on the users's settings in the "Bifacial gain" parameter;

3. Finally, the software calculates electrical losses, and most of the calculation results are based on the values specified by the users in the "Detailed losses".

Taking a certain project as an example, the calculated energy losss diagram is shown below:

Loss items and their corresponding values		Calculation basis
Front-Side Irradiation:
Global horizontal irradiation	1630.0 kWh/㎡	Layout of array within the Model
Global incident in coll. plane	1717.03 kWh/㎡	Layout of array within the Model
Losses related with Front-Side Irradiation:
Far Shadings / Horizon	0.0%	Detailed losses: "Horizon profile"
Near Shadings: Irradiance Loss	0.74%	Layout of array within the Model
IAM Factor on Global	2.06%	Detailed losses: "IAM loss"
Soiling Losses Factor	3.0%	Detailed losses: "Soiling loss yearly"
Rear-Side Irradiation:
Ground-Reflected Irradiation Received on the Rear Side	-kWh/㎡	Detailed losses: "Bifacial gain"
Diffuse Irradiation Directly Received on the Rear Side	-kWh/㎡	Detailed losses: "Bifacial gain"
Direct Irradiation Directly Received on the Rear Side	-kWh/㎡	Detailed losses: "Bifacial gain"
Ground-Reflected Irradiation Received on the Front Side	-kWh/㎡	Detailed losses: "Bifacial gain"
Losses related with Rear-Side Irradiation:
View Factor for Rear Side	-%	Detailed losses: "Bifacial gain"
Mismatch Losses Factor for Rear Side	-%	Detailed losses: "Bifacial gain"
Actual Bifacial Gain	-%	Calculation results
Losses related with Electrical connection:
Module Degradation Loss (for year #1)	0.2%	Detailed losses: "Modules degradation"
PV Loss due to Irradiance Level	0.63%	Rs and Rsh values in "*.PAN file"
PV Loss due to Irradiance temperature	5.76%	Detailed losses: "Thermal loss factor"
Shadings: Electrical Loss acc. to Strings	0.86%	Layout of array within the model
Module Quality Loss	0.0%	Detailed losses: "Module quality"
LID - Light Induced Degradation	0.6%	Detailed losses: "LID loss"
Mismatch Loss, Modules and Strings	2.1%	Detailed losses: 'Mismatch loss'
Ohmic Wiring Loss	0.32%	Detailed losses: "DC side ohmic loss"
Inverter Loss during Operation (Efficiency)	1.47%	Efficiency loss related to "*.OND" file
Inverter Loss over Nominal Inv. Power	0.09%	Efficiency loss and inverter temperature parameter settings in the "*.OND" file
Inverter Loss due to Power Threshold	0.0%	Efficiency loss related to "*.OND" file
AC Ohmic Loss	0.66%	Detailed losses: "Low AC side ohmic loss"
Medium Voltage Transfo Loss	1.17%	Detailed losses: "MV side"
MV Line Ohmic Loss	0.03%	Detailed losses: "HV side"
High Voltage Transfo Loss	1.18%	Detailed losses: "HV sidee"
HV Line Ohmic Loss	0.35%	Detailed losses: "HV side"
Auxiliaries	0.28%	Detailed losses: "Auxiliaries losses"
System Unavailability	0.0%	Detailed losses: "Unavailability loss"