Commercial 5 MW battery park to be developed in Germany

Younicos, which specializes in renewable energy grid integration, will be developing and delivering the fully automated battery park.

From mid-2014, Europe’s first commercial 5 MWh capacity battery park will come into operation in Schwerin, Germany. With this project, Wemag hopes to level short-term fluctuations as well as regulate the supply frequency on the transmission network level. This will in turn aid the safe integration of wind and solar power into the existing network.

Younicos will start work on the park from June this year. Philip Hiersemenzel from Younicos tells pv magazine that frequency regulation is not the only aim of this development. He adds, "Secondary uses such as voltage control, ramping up and black start can be studied too after installation."

As Younicos founder Clemens Triebel mentions in a statement released, efficient storage solutions to balance short-term fluctuations act as powerful leverage for renewables. "Every megawatt of installed battery capacity compensates ten times the otherwise required conventional power plant capacity needed for a stable electricity supply," Triebel adds. In other words more space is created in the network for solar and wind power.

Wemag has nearly 800 MW of capacity powered by renewable sources in the region. The site in Schwerin is therefore optimal for this commercial project. The grid stabilization will work on different voltage levels and battery storage will be coupled on a 110-kV substation in Schwerin-Lankow. Thereby the integration into the regional distribution grid and a connection to the nearby 380 kV high-voltage grid is possible.

Battery selection and subsidies

Samsung SDI was selected as supplier of the Li-ion batteries that will be used in the project. The important questions posed in the selection procedure were: which batteries/technologies have the highest commercial potential and which batteries can be implemented over the next 20 years? High cycle life, depth of discharge (DOD) and most importantly, safety, were the three decisive factors. Hiersemenzel adds, "Samsung SDI’s 20-year guarantee was the game changer. This makes them bankable."

Younicos evaluated 27 of the most promising storage technologies with focuses on durability, reliability, safety, economic viability and future cost-reduction potential. Three technologies were narrowed down: Li-ion, sodium-sulphur and Vanadium-Redox-Flow (VRF).

Hiersemenzel explains that Li-ion has a different market from sodium-sulphur and VRF. Suppliers are easier to find for the latter as the number of companies that manufacture such types are not many. For Li-ion this was a different case as solutions were widely available, but were not really suited for large-scale stationary projects. Upon further research and evaluation, Younicos found the right partner in Samsung SDI.

To cover the initial project risks, Younicos has applied for subsidies. It is not akin to FITs nor to a permanent subsidy, rather this is a one-off subsidy. "Over the next years the battery cell prices will go down and as it gets more competitive we will get less dependent on subsidies," Hiersemenzel adds.

Germany’s PV storage incentive program is set to come into force tomorrow, May 1 with a €25 million funding available in the first year. pv magazine will provide more details on the program in due course.