engineering careers  This German town disconnected from grid, goes 100% renewable (for an hour)!
engineering careers  This German town disconnected from grid, goes 100% renewable (for an hour)!

Bordesholm, a small town in Schleswig-Holstein Germany, became a showcase for how communities could switch over to renewable energy for a few hours this week.

Bordesholm wanted to demonstrate how it could use its existing renewable energy capacity reliably to go off-grid. To do this; the town pulled its connection from the national grid for a one hour period; allowing all its power to be drawn from local green energy networks.


Pictured; the Sunny Central Storage battery inverter and SMA Hybrid Controller XL, were used in a trial

The region already has great green credentials; in 2018 Schleswig-Holstein broke ground on a 10MW energy storage system in Bordesholm that was funded by the European Union and supported by the local state government. The system can pack 10MW peak power output and boasts a 15MWh storage capacity, utilising lithium nickel manganese cobalt (Li-NMC) batteries.

Tom Scoot explains the importance of frequency containment reserves

Currently, that battery systems is providing ‘frequency containment reserves’ to the local network, in layman’s terms, it uses stored power to stabilise the grid. Unlike big fossil fuel power stations, most renewable energy output isn’t consistent and additional power needs to be put into or taken out of the grid to stabilise the supply.

By helping to better integrate renewable energy into the grid the system allows for a wider reduction in carbon emissions. However, the design also means it can be used as a standalone grid. The idea is that it could be used during larger national power cuts or in an emergency.

The test at the end of November was meant to demonstrate how that fallback system should work. Bordesholm was successfully disconnected from the national grid for one hour and during that time was powered completely by the renewable battery system. The test is important because it shows how an already economically profitable system can be used to expand renewable capacity without impacting on reliability.

Here in the UK, the National Grid has said it wants to see a similar energy storage system provide the same type of function the grid.

Bordesholm power is now 75% renewable, but the small town’s 8,000 inhabitants hope to see it reach 100% during 2020.