What is SoDeLe?

SoDeLe is a photovoltaic simulation tool within the QuaSi software environment. The name is an acronym for the German phrase Solarsimulation denkbar leicht, which can be translated as solar simulation made easy.

SoDeLe calculates PV yield profiles from weather data, module data, inverter assumptions, and the geometric orientation of one or more PV systems. It is intended for energy-system studies, district simulations, and early-stage planning tasks where reproducible PV time series are required but a full commercial PV design workflow is not necessary.

The calculation core is based on the Python library pvlib¹. SoDeLe adds a practical workflow around pvlib: Excel-based input files, support for EPW and DWD weather files, access to module and inverter databases, and structured result files.

Purpose and scope

A PV system in SoDeLe is described by its orientation, tilt, module type, inverter model or constant inverter efficiency, electrical configuration, and weather file. The main output is a PV energy time series. Additional outputs contain annual yield values, area-specific and peak-power-specific values, aggregated results for several PV systems, and plots.

Typical applications are:

• generating annual PV production profiles for energy-system simulations,
• comparing PV orientations, tilts, or module layouts,
• preparing PV input profiles for district-level studies,
• estimating PV yield in early project phases,
• running scripted simulations from JSON input files.

SoDeLe is not a detailed PV plant design tool. It does not replace string-layout verification, shading analysis, mounting-system design, grid-connection planning, or project-specific engineering checks.

User interfaces

SoDeLe can be used in three ways:

1. with the simplified Excel interface,
2. with the extended Excel interface,
3. from the command line with a JSON input file, either through the precompiled SoDeLe.exe or through the Python source code.

The Excel interfaces and the executable are intended for users without a Python installation. The command-line and Python workflows are intended for power users, automated workflows, and reproducible studies.

Both Excel interfaces use the same calculation core:

Interface	Intended use
Sodele_Input_DE_simplified.xlsm	Fast PV yield estimation with reduced input requirements and a constant DC-to-AC efficiency.
Sodele_Input_DE_extended.xlsm	Detailed PV system definitions with specific module and inverter selection and explicit electrical configuration.

The files are available in the SoDeLe repository in the folder precompiled_with_frontend.

This folder also contains the precompiled SoDeLe.exe and the required src folder with database resources. The Excel interfaces are currently provided in German and require Microsoft Excel with macro support on Windows.

Data basis and limitations

SoDeLe supports EnergyPlus weather files (.epw) and DWD weather files (.dat) from the German Weather Service climate consulting module, available here. Weather files are preprocessed internally before the pvlib calculation is performed, including time-stamp handling and, for DWD files, calculation of direct normal irradiance.

PV module and inverter parameters are read from public pvlib-compatible databases, including the CEC database from the System Advisor Model (SAM) by NREL and data provided with pvlib. For scripted workflows, the internal database names must be used exactly.

Relevant modelling limitations are:

• shading is not modelled,
• the simulation time step is determined by the weather file, typically one hour,
• result quality depends on the weather file, module entry, inverter entry, and electrical configuration,
• facade-mounted PV systems can be sensitive to weather-data conventions and diffuse-radiation assumptions (applies to all PV simulation tools).

Detailed instructions are provided in the SoDeLe User Manual.