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INSEL

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INSEL is a block diagram simulation system for programming applications from the entire renewable energy sector. INSEL is mainly designed for engineering and other firms working on large and complex energy projects and is ideal for use in research and education.

INSEL offers users ready-made simulation models for a quick start. But users can design completely new models for all kinds of system applications with the help of the comfortable and powerful INSEL graphics editor. In addition, INSEL offers a unique interface for the extension of the block libraries in programming languages like Fortran and C/C++. INSEL can also be called from Python, with inselpy.

INSEL is now freeware: it can be downloaded, copied and used at no cost. It might become open-source in the future.

Download page.

News

  • Jürgen Schumacher, creator and lifelong developer of INSEL, passed away in 2020.
  • INSEL is still developed by an international team of developers (Guillermo Gutierrez Morote, Kai Brassel, and Eric Duminil).
  • The goal is to keep maintaining and improving INSEL.
  • INSEL is still used actively, e.g. in the SimStadt platform.

Applications

Simulation of photovoltaic systems

The Solar Electricity and Solar Thermal Systems libraries contain the main models and data for the simulation of photovoltaic modules, inverters and solar thermal components. Several thousand parameter sets for the one-diode model cover nearly all commercial PV modules in the INSEL database.

A parameter fit algorithm extracts the six parameters from manufacturers' data sheets or flasher data to calculate the voltage-current characteristics for all meteorological conditions. With the help of the one-diode model curves the operating points of a PV generator can be simulated very accurately.

Simulation of the characteristic curves can answer detailed questions such as:

  • What are the advantages of pre-sorting modules?
  • How much yield losses can be expected if the nominal power of the inverter is less than ideal?
  • How big is the effect on efficiency of different module mountings?
  • How good is the performance of thin-film technologies in weak-light?

All kinds of PV generator connections are possible and shading of individual modules can be researched in detail. Batteries, charge controllers, wind turbines, electrolyzers, fuel cells, heat pumps and many other electrical and thermal energy systems can also be simulated.

Synthesis of meteorological time series

Nearly every simulation of a solar energy system starts with the need for meteorological data for the location of a project. INSEL offers several algorithms to work with these data in the Solar Meteorology library. The library contains a database for 2000 locations worldwide including monthly mean values of global radiation, temperature,wind speed, humidity etc.

Highly efficient statistic models use the monthy means to generate time series in hourly resolution of arbitrary length. The time series of solar radiation and ambient temperature are validated with measured data from all continents.

The statistic of the time series has an excellent correlation with monitored real data. Hence, INSEL offers a good basis for the calculation of energy yields from solar energy systems.

Dynamic building simulation

The latest new development in INSEL is a library for dynamic building simulation. INSEL can calculate an annual energy demand profile for heating and cooling with arbitrary time resolution on the basis of 3D geometry data from SketchUp or urban CityGML geometries, for instance. A speciality of the new library is the highly modular structure of all components which make up a building.

Every individual wall is simulated dynamically and all variables of the simulation model can directly be accessed. Thus, detailed building physics problems can be solved.

On the other hand, the modular blocks can be coupled with 3D geometry data from BIM- (Building Information Modeling) or city modeling world.

Complete city quarters can be simulated dynamically and the most important topics of energy management can be investigated, for example, feed-in of decentralized renewable energy, or the use of a building‘s thermal mass to create flexibility. It is also possible to create energy certificates following the German standard DIN 18599.

History

  • Jürgen Schumacher created INSEL in 1986 at University Oldenburg, for his PhD thesis.
  • Jürgen brought INSEL to Zafh.net at HfT Stuttgart, and kept working on it. Many colleagues started developing INSEL blocks, which were integrated into the library.
  • INSEL was used for the planing of many photovoltaic power plants over the world.
  • INSEL has been used for teaching purposes, among others in SENCE Master courses.
  • Jürgen brought INSEL to Concordia Next-Generation Cities Institute.
  • Friends and colleagues of Jürgen kept working on INSEL after 2020.