Topic of the Week: Off-grid PV (Part 5): Taking an entire town off the grid

2/21/20, 5:06 PM -

Late last year, the town of Bordesholm in Schleswig-Holstein became the first town in Germany to be taken off the utility grid and powered by renewables.

Combine storage systems and battery inverters for clean power supply
SMA's 10-megawatt storage system and the Sunny Central Storage battery inverters.

Taking an entire town off the public grid would seem to be a crazy and even scary thing to do, right? Read on to find ot what happened when that way actually done:

The 7,500 inhabitants of Bordesholm did not notice a thing when their power supply was completely switched over to renewable energy. On a weekend in late 2019, Bordesholm became the first ever town in Germany to be disconnected from the utility grid and supplied exclusively with renewable energy for an hour, before being discreetly reconnected to the transmission line. The power supply was enabled by a 10-megawatt storage system and the Sunny Central Storage battery inverters by SMA Solar Technology AG.

“This successful trial is an important milestone in the energy transition,” said Boris Wolff, Executive Vice President for Large-Scale and Storage Solutions at SMA. “It demonstrated that renewable energies can supply power without impacting system stability. In fact, our Sunny Central Storage battery inverters and SMA Hybrid Controller supply the island grid with even greater stability and power quality than the utility grid.”

An optional 'black start' function

“The disconnection, the island grid operation, and the re-synchronisation with the utility grid went without a hitch,” said SMA system development engineer Paul Robert Stankat, who was on site for the trial run. “The storage system supplied the town’s entire electricity demand which could thus be supplied exclusively from renewable energies.”

In addition to a grid formation function, the SMA battery inverters are also equipped with an optional 'black start' function, which allows the entire electricity supply to be restarted after a power outage. If the trial had been unsuccessful, the residents of Bordesholm would have had their power restored within just a few minutes.

Did you know?

On the Island of Saba, a system like this one saves a million litres of diesel per year.

Bordesholm is a pioneer in energy security – also from exclusively renewable sources: “The trial run was an impressive demonstration of how it is already possible and economically profitable to systematically expand renewables along with the required storage capacities without endangering supply reliability whatsoever,” said Frank Günther, managing director of the Bordesholm utilities company. “We have been pushing this nationwide pioneering project forward for many years. Now we have proven that a fully renewable energy supply is both reliable and economically efficient. This makes our municipality a pioneer throughout Europe for energy reliability. We have been able to show that system stability can also be achieved with renewables only.”

In Bordesholm a 10-megawatt storage system with a capacity of 15 megawatt hours and provided by project developer Renewable Energy Systems (RES) entered service in early 2019. Its main job is to deliver a primary operating reserve, supply electricity for direct marketing and it is also designed to safeguard the power supply in the event of a grid failure. SMA supplied a coordinated system solution for the project comprising Sunny Central Storage battery inverters and an SMA Hybrid Controller XL equipped with stand-alone mode, black start and synchronisation functions. (mfo)

Here, in case you missed them, are Part 1, Part 2, Part 3 and Part 4 of this week's series. Next week, we will come back to what is more our core business: solar panels. But not just any solar panels, mind you...