Renewable electricity self-sufficiency: it also works without an overland grid

Renewable electricity self-sufficiency: it also works without an overland grid

Well, it was "only" a test, part of the IREN2 research project. A section of the low-voltage grid of the energy community known for innovation was "successfully disconnected from the public grid and deliberately de-energized. This can happen, for example, in the event of a fault or, even worse, a blackout," explained Siemens, AÜW, AllgäuNetz, ID.KOM, RWTH Aachen and Kempten University of Applied Sciences afterwards. However, those involved in the trial did not leave it at that: "In the trial, the so-called "black start" of this island grid was tested. This could be restarted and stabilized using the integrated decentralized generation and storage systems."

In other words, the decoupled grid restarted and stabilized itself without interruption. Which is why "this disconnection had no effect whatsoever on the connections of the households integrated in the trial", as the Allgäuer Überlandwerk GmbH AÜW enthusiastically announced.

This is not only "an important milestone" for AÜW Managing Director Michael Lucke. The success also shows that if renewable energy is to be fully utilized and no longer curtailed when the last nuclear power plants are phased out in five years at the latest, then regional power cells are needed that are as self-sufficient as possible. Wildpoldsried is already multiple self-sufficient: solar, wind and bio power plants generate seven times more energy than is consumed in the village. This makes the municipality an ideal showcase for decentralized microgrids.

But it also works elsewhere. For example, the blackout in the distribution grid was successfully tested in the Gammel Engineering office building. "The disconnection from the grid did not lead to any outages or difficulties; decentralized generators in conjunction with our iCube storage system took over the secure supply," recalls Managing Director Michael Gammel.

The latest trial in Wildpoldsried also proved this: Consumers need have no fear that their electricity supply will become less secure with renewable energies. In the end, "the stand-alone grid was synchronized with the public grid again without interruption. At the touch of a button, it was switched to stand-alone operation and back again without interrupting the power supply," confirms AÜW, the regional grid operator in the Allgäu region. Which clearly shows: The technology for decentralization and also the artificial intelligence for measurement, control and regulation technology is available and works. Commercial areas could therefore also be supplied reliably: You only need to install the appropriate decentralized energy systems, for example decentralized combined heat and power systems, if`it has to be also based on natural gas.

Hopefully, energy politicians at federal and state level will take the test result as an incentive to rethink, and they will finally listen to and look at small municipalities and regional suppliers such as those in Wildpoldsried and the Allgäu region. Because so far, they have mostly hung on the lips of the "big players" in the electricity industry and the four transmission system operators.

The practical experience in Wildpoldsried is definitely both a reassurance and a challenge for local and regional energy service providers. Because now one thing is certain: decentralization does work.

Or the other way round: from now on, no one can make excuses by saying: "I didn't know that stand-alone grids work."

(Author: Zukunftsenergie-Team Gammel)