Pvsyst Premium for Windows PC. It is designed to be used by architects, engineers, and researchers. It is also a handy educative tool.

It includes a detailed contextual Help menu that explains the procedures and models used and offers a user-friendly approach with a guide to developing a project. PVsyst can import meteo data from many different sources and personal data.
Overview of Pvsyst Premium 

PVsyst is a software package for studying, sizing, simulation, and data analysis of PV systems. You can incorporate PVsyst data from a specially formatted comma-separated value (CSV) file in your HOMER models using a Wizard or creating a Custom Component.

PVsyst is a photo-voltaic design and simulation program. An extensive database of PV components, locations, and meteorological sites is included in the application itself. The 3D CAO tool allows the user to draw the geometry of the complete system. It computes a shading factor for the beam component as a function of the sun's position.
Features of Pvsyst Premium

    Direct search for a location using Google Maps
    Complete Meteonorm interpolation program for any location on earth
    Defines the position of all modules of the system in the 3D field
    Computes the electrical circuit at the input of each inverter
    Outputs: “Irradiance shading loss” and “electrical shading loss”
    Direct shading calculation during the simulation (avoids interpolation uncertainties)
    Big plants: optimized calculation of the shading factor
    Plants following the terrain (Helios 3D): orientation analysis and management
    Improved project management: parameter access, copy, templates
    The new organization of the losses
    New losses like LID, unavailability, and light-soaking gain for CIS
    Sandia model implementation and comparison with the PVsyst model
    Tools for parameter optimization (low-light, I/V curve)
    New parameters (tolerance, IAM profile, Vmax UL)
    New parameters (Transfo, CEC efficiency)
    Multi-MPPT with asymmetric inputs
    Improvement of choice by manufacturer
    Batch model for parametric studies

System Requirements and Technical Details

    Supported OS: All Windows client versions currently supported by Microsoft: 7/8/10 32/64 bit
    Processor: Pentium IV or above
    RAM: 1 GB RAM (2 GB recommended)
    Free Hard Disk Space: 1 GB or more
    Minimal screen resolution of 800 x 600 pixels (SVGA)
    .NET 4.5 framework
    Graphics card supporting OpenGL 2.0 or higher