Blackout on the Iberian Peninsula: EIZ professors publish technical analysis

On 28 April 2025 at around 12:33 CEST, a blackout occurred in Spain and Portugal. As information for staff members and students at BTU Cottbus-Senftenberg, Professors Mario Schenk (Chair of High Voltage Engineering and Electrical Systems), Kaveh Malekian (Chair of Decentralised Energy Systems and Electrical Grids) and Harald Schwarz (Emeritus Chair of Energy Distribution and High Voltage Engineering), who also work in the Electric Power Systems (EPS) Lab at the Energy Innovation Centre (EIZ), explain how the blackout occurred. Energy Innovation Centre (EIZ) are researching what conclusions can be drawn about the sequence of events - based on publicly available information.

Technical analysis of the blackout on the Iberian Peninsula

The critical grid and supply restoration process usually takes place within the first few hours after a blackout. At BTU Cottbus-Senftenberg, scenarios for grid restoration and other critical grid states are simulated in real time in the power system simulator laboratory using real grid models and analysed from various perspectives.

The signatories see this information as a summary of the currently available information in the sense of a more technology-oriented specialist discussion and hope to have awakened an understanding of why the current analyses are technically very complex and also time-consuming.

Prof. Dr.-Ing. Mario Schenk
Chair of High Voltage Technology and Electrical Annexes
T +49 (0) 355 69 4503
mario.schenk(at)b-tu.de

Prof. Dr.-Ing. Kaveh Malekian Boroujeni
Chair of Decentralised Energy Systems and Electrical Grids
T + 49 (0) 355 69 4030
malekian(at)b-tu.de

Prof. Dr.-Ing. Prof. h.c.mult. Harald Schwarz
Emeritus of the Chair of Energy Distribution and High Voltage Engineering
T +49 (0) 355 69 4502
harald.schwarz(at)b-tu.de

At the Cottbus Energy Innovation Centre (EIZ), more than 80 scientists from BTU Cottbus-Senftenberg are working together with an interdisciplinary network of partners in six networked laboratories to research innovative solutions and technologies for a climate-neutral energy supply in Lusatia and worldwide.

The Electric Power Systems (EPS) Lab deals with grid operation issues relating to decentralisation and conversion in the generation sector. The focus at transmission and distribution grid level is on the simulator-based investigation of system management and grid reconstruction. An operationally realistic grid training simulator (Power System Simulator, PSS) is being further developed for this purpose. For research work at the low-voltage level, a smart grid real laboratory is being created in which the coupling between the electricity, heating, cooling and mobility sectors is made possible on a real system infrastructure in order to investigate technologies and their cross-sector interconnection in real operation.

The EPS Lab is also dedicated to the dimensioning and insulation of high-voltage switchgear, which is exposed to changing insulation stresses due to increasing inverter-fed generation. In annex-oriented laboratories, such as the high-voltage hall and the climate chamber, the behaviour of future high-voltage operating equipment with new environmentally friendly insulating materials (instead of SF6 and mineral oils) is investigated under climatic and pollution conditions.