A flexible battery testing framework for accelerated research on photovoltaic-battery modules and a representative test time series

Journal of Energy Storage, vol. 179, pp. 124007

Abstract

Surplus variable photovoltaic (PV) generation should be coupled to storage as close as possible to its point of generation to minimize grid stress and infrastructure expansion. This can be achieved by electrically coupling and physically integrating batteries at the PV module level, an approach that has been shown to be feasible but requires batteries adapted to PV-module-specific electrical and thermal operating conditions. In direct coupling, the battery current is set by the instantaneous interaction of PV and battery current-voltage characteristic, and the thermal conditions are dominated by the PV module temperature. Existing battery testing methods do not fully address this requirement space for early-stage laboratory cells. Here, we present a flexible battery testing framework that translates direct PV-battery coupling and PV-module thermal boundary conditions to laboratory-scale batteries. The platform combines a software-controlled PV emulator with a programmable thermal chamber to expose batteries to scaled PV I-V characteristics and PV-module-equivalent temperature profiles. It is demonstrated using a Li-ion cell under a representative seven-day PV profile for Freiburg, Germany. The emulator reproduces the target electrical conditions with cumulative charge and energy deviations of about 1.5%, while the tested configurations show PV-battery coupling efficiencies above 95%. The results demonstrate the platform's potential for screening laboratory-scale batteries by assessing relative PV-battery sizing, voltage matching, C-rate variation, state-of-charge swing, and direct-coupling behavior. The derived battery operating time series is also provided as a simplified proxy for preliminary screening on conventional battery cyclers.

Authors 9

1. N'Danadje Bagnabana Konga

   Université Abdou Moumouni · Forschungszentrum Jülich

   Affiliation as printed

   Faculty of Science and Techniques, Abdou Moumouni University, 10662, Niamey, Niger

   IMD3-Photovoltaics, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany

2. Sergey Shcherbachenko

   Forschungszentrum Jülich

   Affiliation as printed

   IMD3-Photovoltaics, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany

3. Oleksandr Astakhov corresponding

   Forschungszentrum Jülich

   Affiliation as printed

   IMD3-Photovoltaics, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany

4. Daniel Weigand

   Forschungszentrum Jülich

   Affiliation as printed

   IMD3-Photovoltaics, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany

5. Ayouba Mahamane Abdoulkadri

   Université Abdou Moumouni

   Affiliation as printed

   Faculty of Science and Techniques, Abdou Moumouni University, 10662, Niamey, Niger

6. Souley Kallo Moutari

   Université Abdou Moumouni

   Affiliation as printed

   Ecole Normale Supérieure, Abdou Moumouni University, 10662, Niamey, Niger

7. Egbert Figgemeier Aachen Faculty of Electrical Engineering and Information Technology

   Forschungszentrum Jülich · Helmholtz-Institute Münster · RWTH Aachen University

   Affiliation as printed

   Faculty of Electrical Engineering and Information Technology, RWTH Aachen University, 52062, Aachen, Germany

   Forschungszentrum Jülich, Helmholtz Institute Münster, 48149, Jülich, Germany

8. Christoph Josef Brabec

   Forschungszentrum Jülich · Friedrich-Alexander-Universität Erlangen-Nürnberg

   Affiliation as printed

   Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058, Erlangen, Germany

   IMD3-Photovoltaics, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany

9. Tsvetelina Merdzhanova

   Forschungszentrum Jülich

   Affiliation as printed

   IMD3-Photovoltaics, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany