Harmonics in the island grid
At the 25th Wind & Solar Integration Workshop in Porto, TU Braunschweig shows how grid-forming inverters damp voltage harmonics – with measurement data from the Fuchstal island grid.
To the publications
Research project · Energiezukunft Fuchstal living lab
The power grid of the future – tested in Fuchstal
“Fuchstal leuchtet” investigates whether a medium-voltage grid supplied exclusively by inverters can be operated stably – without large power plants and without central control.
The research question
Can a grid run on inverters alone?
With the energy transition, wind and solar plants are replacing large power stations. They feed in via inverters and have no rotating masses, which have so far stabilised the grid. The European interconnected grid is expected to reach this situation around 2040.
The Energiezukunft Fuchstal already corresponds to this grid of the future today. This makes it possible to answer questions in real operation that simulations alone cannot.
How can stable grid operation be achieved in practice in a grid without a central control structure that is supplied and loaded exclusively by power converters?
The living lab in figures
Energiezukunft Fuchstal
A battery storage system, a wind farm, a power-to-heat plant with heat storage and the villages of Asch and Leeder form a grid section that can be disconnected from the interconnected grid.
3.35 MWh
Battery storage
2 × 2.9 MW
Grid-forming inverters
4 × 3 MW
Wind turbines
4.7 MW
Power-to-heat with heat storage
20 kV
Medium-voltage grid
Step by step
Three consecutive field tests
Each field test is prepared with simulation models and adds further plants to the island grid – until finally the Fuchstal villages of Asch and Leeder are supplied.
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Field test 1 · October 2024
The battery carries the island grid
Two grid-forming inverters supply the power-to-heat plant, a load bank and a cable section.
Completed -
Field test 2 · 16–18 September 2025
The wind farm joins in
Grid-forming and grid-following plants working together – three days of stable island grid operation.
Completed -
Field test 3 · 23–27 November 2026
Asch and Leeder in the island grid
The villages of Asch and Leeder are disconnected from the power grid for half a day and supplied as an island grid – the practical proof for the grid of the future.
Planned
News
News from the project
Strategies against inrush currents
The results of the second field test on transformer inrush currents were presented at the Hybrid Power Plants & Systems Workshop in Sardinia.
More on field test 2Safe experiments in living labs
How risk management safeguards the field tests is shown in the contribution by Munich University of Applied Sciences to the Symposium Energieinnovation in Graz.
To the press releaseFirst field test successful
On 2 October 2024, the island grid ran exclusively on the grid-forming battery inverters for the first time – 15 parameter scenarios were tested.
More on field test 1Consortium
Working together on the grid of the future
Munich University of Applied SciencesInstitute for Sustainable Energy Systems (ISES)
Augsburg Technical University of Applied SciencesFaculty of Electrical Engineering, High Voltage Laboratory
TU Braunschweigelenia Institute for High Voltage Technology and Power Systems
The project “Fuchstal leuchtet” is funded by the German Federal Ministry for Economic Affairs and Climate Action (BMWK) on the basis of a decision by the German Bundestag.
