Successful test of island grid as milestone for an energy transition project

In Wildpoldsried, Siemens experts have succeeded in decoupling a local power network from the public grid. This is an important step in advancing the transition to a new energy mix. In a five-stage process, they demonstrated how the local grid could be switched to isolated operation at the push of a button.

Wildpoldsried is a special location. Over the whole year, it generates seven times as much power as it consumes. And that's just from renewable energy sources. The isolated network trial proved a success and showed that the local grid can be switched to autonomous operation with no interruption to service.

The small community in the Allgäu district is a good location for a pioneering trial. Energy pioneers from Siemens and its partner companies have been experimenting here for years now, to determine the form that a future intelligent power network – a Smart Grid – can take. Intelligent controller and energy storage enable these networks to keep volatile generation and consumption in balance, thus making stable grid operation possible. Since 2011, as part of the research projects Irene and IREN2, Siemens has worked with partner entities Allgäuer Überlandwerk AG, ID.KOM, RWTH Aachen, and Kempten University to build and test a Smart Grid in Wildpoldsried. The isolated network trial was the culmination of many years of research and testing.

Depending on the amount of sunlight available, the lithium-ion battery has to either temporarily store surplus power or feed it when needed. The battery has a maximum output of 300 kilowatts and a capacity of 138 kilowatt-hours.

Experts from Siemens, working with partners from science and industry, have succeeded in demonstrating that a local electricity grid can function in isolation, using Wildpoldsried as an example. Such autonomous grids help ensure a reliable power supply even in the case of disruptions like storms or floods. To begin with, the experts initiated a deliberate power failure, putting out the lights in the affected part of the low-voltage grid. They then restored the power supply, but as a local isolated network this time.

Experts from Siemens, working with partners from science and industry, have succeeded in demonstrating that a local electricity grid can function in isolation, using Wildpoldsried as an example. Such autonomous grids help ensure a reliable power supply even in the case of disruptions like storms or floods. To begin with, the experts initiated a deliberate power failure, putting out the lights in the affected part of the low-voltage grid. They then restored the power supply, but as a local isolated network this time.