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System Design Board

The system design is based on a quick and simple procedure:

  • Specify the desired power or available area
  • Choose the PV module from the internal database
  • Choose the inverter from the internal database

and PVsyst will propose an array/system configuration, that allows you to conduct a preliminary simulation.

The software embeds a color-coded warning / errors messaging system. If there’s a mismatch, issue, warning with your design, you will be warned within the proper frame.

System sizing: Visual tool

A specific tool gathers all constraints for the sizing of the system :

For the number of modules in a series: the upper diagram shows the I/V curve of the PV array, together with the MPPT range, voltage, power, and current limits of the inverter.

  • For the inverter sizing: the second graph displays the annual distribution of the array power, with the array and inverter nominal power
  • The optimal sizing of the inverter is based on the acceptable overload loss throughout the year. It usually leads to over-size the power ratio (array nominal power by respect to the inverter nom. AC power), by a factor of 1.25. After a good system sizing, you can define different losses like far and near shadings using a full 3D editor for the definition of the environmental and near shading conditions. Specialized tools are also provided for the evaluation of the wiring losses (and other losses like the module quality), the mismatch between modules, soiling, thermal behavior according to the mechanical mounting, system unavailability, etc.

3D Shading Scene

  • User-friendly object manipulation and creation
  • Easy import from external CAD tools (Sketchup, Helios3D, AutoCAD, etc)
  • Quick design: sheds layout, zones of tables
  • Orientation identification and scene validation tools
  • Sun Point of View Simulation
  • Multithreaded shading calculations

Simulation and results report

The simulation calculates the distribution of energies throughout the year.

Main results:

  1. The total energy production [MWh/y] is essential for the evaluation of the PV system’s profitability.
  2. The Performance Ratio (PR [%]) describes the quality of the system itself.
  3. The specific energy [kWh/kWp] is an indicator of production based on the available irradiation (location and orientation).
  • Shows the main energies and gains/losses involved in the simulation,
  • Powerful tool for a quick analysis of the system’s behavior, and potential improvements in the design.

Grid Storage

Storage in a grid system is a complex feature, as it may have different objectives, which lead to different strategies and different PV system configurations. Up to now, we have developed 3 strategies in PVsyst:

  • the storage for enhancing the self-consumption of the PV system owner.
  • a storage for ensuring peak shaving, when the possible power injected into the grid is limited.
  • a storage for the continuity of the user’s electricity feeding, when the grid is weak and often unavailable.

In each case the energy fluxes are different and lead to different simulation results.
As an example we show the energies involved in a self-consumption PV system.

Meteonorm included – 8.0

  • Direct search for a location using OpenLayers and GeoNames
  • Full Meteonorm v8.0 interpolation program for any location on earth

PV modules and Model Management, Inverters

PV modules and model Management

  • Sandia model implementation and comparison with PVsyst model
  • Tools for optimization parameters (low-light, I/V curve)
  • New parameters (tolerance, IAM profile, Vmax UL)
  • Optimizers (SolarEdge and Maxim)


  • New parameters (Transfo, CEC efficiency)
  • Multi-MPPT with asymmetric inputs (unbalanced) and advanced Power Sharing
  • Improvement of choice by manufacturer


Multi-year batch simulation:

  • For different operating years, same meteo data
  • For a set of yearly meteo data files
  • Results and graphs on the report

Bifacial calculations

Bifacial model for tracking 1-axis systems (unlimited trackers)

  • Improved the import parameters from the “real” system defined in 3D
  • Conceptual error in the model, which lead to an underestimation of the rear side irradiance by a factor of 1/GCR (i.e. a factor of 2 or more!)
  • Add the contribution of the Diffuse seen from the rear side.
  • Albedo in monthly values.Seasonal orientation: possibility of negative summer tilt for low Latitudes

Batch calculations

Batch mode and sheds optimization tool

  • Modification of the pitch as parameter
  • Bi-facial: height above ground as parameter

Economic evaluation

System cost evaluation:

  • CAPEX (installation cost)
  • OPEX (operating costs)
  • Abiltiy to define customized costs according to own system

Pricing strategy:

  • Detailed feed-in tariffs definition: fixed, variable or customized, hourly or seasonal variations
  • Selling policy: connection tax, yearly tariff variation, duration of tariff warranty
  • Parameters for self consumption economy

Advanced financial analysis:

  • Investment funds distribution: own funds, loans or subsidies
  • NPV (Net Present Value) and LCOE (Levelized Cost of Energy) calculation
  • Inflation, discount rate and detailed depreciation management

Profitability analysis :

  • Yearly balance, payback period and return on investment rate
  • Graphical results: tables, plots and pie charts