Fraunhofer Institute for Solar Energy Systems ISE
Fraunhofer Institute for Solar Energy Systems ISE

Featured Publications Q2-2023

Design and Analysis of Charge-Reduced Refrigerant Cycles Using R290

Division Heat and Buildings

© 2023 The Authors. Chemie Ingenieur Technik published by Wiley-VCH GmbH

Chemie Ingenieur Technik | Volume 95: 353-362. | März 2023

Lena Schnabel, Timo Methler, Abdelrahman H. Hassan, Clemens Dankwerth, José María Gonzálvez Maciá

 

The use of natural refrigerants in heat pumps and chillers is becoming more and more urgent. Fraunhofer ISE is working intensively on the use of the natural refrigerant propane/R290, which is thermodynamically suitable for many applications, but is subject to restrictions due to its flammability. Therefore Fraunhofer ISE is working with partners on refrigerant-reduced refrigeration circuits and has published pioneering design criteria in this article.

 

Novel method for the parameterization of a reliable equivalent circuit model for the precise simulation of a battery cell’s electric behavior

Division Power Solutions

© 2021 The Authors. Published by Elsevier B.V.

Journal of Power Sources | Volume 490 | 1 April 2021 | 229513

Maximilian Bruch, Lluis Millet, Julia Kowal, Matthias Vetter

 

In this paper we introduce an advanced process to extract reasonable parameters for an electric model from a measurement. The step-by-step approach solved the problem of over- or underfitting and since only a few parameters are determined in each step, the identification of the correct values of the parameters is much more likely. Validation is shown over the complete state of charge range as well as for slow and fast dynamics loads. As an essential innovation, a voltage limitation for RC elements is introduced, which leads to a good description of the slow voltage effects (e.g., relaxation). It has become one of our standard tools to elaborate and parameterize models and is used in our research and as well as for related services in the field of characterization of battery cells and systems.

 

The MorphoColor Concept for Colored Photovoltaic Modules

Division Photovoltaics

© This work is licensed under a Creative Commons Attribution 4.0 License

IEEE Journal of Photovoltaics | Vol. 11, No. 5 | September 2021 | pp. 1305-1311

Benedikt Bläsi , Thomas Kroyer, Tilmann E. Kuhn and Oliver Höhn

 

In this paper, we introduce a photonic color concept for integrated photovoltaic modules. Taking up the inspiration from the Morpho butterfly with its brightly colored wings, we developed this photonic concept further to achieve an improved angular independent color effect and compatibility with industrial production, while maintaining very high module efficiencies. The power output for the MorphoColor® modules is more than 94% compared to the black reference modules. The concept was patented by Fraunhofer ISE and has now achieved market maturity: Recently it was licensed to the Swiss module producer Megasol Energie AG.

 

Catalyst screening and reaction kinetics of liquid phase DME synthesis under reactive distillation conditions

Division Hydrogen Technologies

© 2022 The Authors. Published by Elsevier B.V.

Chemical Engineering Journal | Volume 455 | 1. Januar 2023 | 140525

M. Semmel, L. Steiner, M. Bontrup, J. Sauer, O. Salem

 

Due to their high energy density, chemical energy carriers such as dimethyl ether (DME) provide the opportunity to store fluctuating renewable energies and to transport them efficiently and cost-effectively. However, the conventional DME production process is found to be insufficient due to the large number of steps involved and the high external heat demand. DME production by reactive distillation represents a more efficient and economical process alternative. The basis for this process is shifting the reaction to the liquid phase and lower temperatures. In the presented work, several potential catalysts were compared in a catalyst screening. A catalyst enabling significantly higher reaction rates was found and a kinetic model was developed for this catalyst.