Press Release Events
16.04.2010|GILDEMEISTER expands its division of renewable energy​​​​​​​

a+f acquires majority stake in Cellstrom

Bielefeld. The GILDEMEISTER subsidiary, a+f GmbH based in Wurzburg, which specialises in renewable energy, is acquiring a majority holding (50.001%) in the Austrian company, Cellstrom GmbH, based in Eisenstadt near Vienna. As part of the transaction, a+f is also acquiring a 5% holding in the parent company, Younicos AG, Berlin. Through this, a+f is paving the way for its entry into the promising future market of energy storage; the Cellstrom large battery is based on vanadium redox flow technology.

Cellstrom GmbH was founded in 2000 and specialises in innovative storage solutions – especially for solar plants. The powerful, long-lasting and low maintenance vanadium redox flow battery solves the problem of energy storage. The large battery achieves constant power supply from solar and wind installations, even in the dark and when there is no wind. After years of research, the energy storage system from Cellstrom has reached series production readiness.

With the joint know-how of the companies – Younicos / Cellstrom as a specialist of storage and grid for renewable energy sources and GILDEMEISTER as the innovative technology group full of tradition – the storage technology business is expected to reach double-digit sales figures in the millions from 2011 on. In future, customers will be able to use their electricity independently and flexibly at any time. The use of the storage system as a solar filling station is also of interest. Using a large battery, eight electric cars can be “re-fueled“ up to 80% simultaneously in less than 10 minutes, or 80 four-person households can be supplied with electricity for an entire night.

The Cellstrom battery system allows the clean, emission-free and quick supply of energy at any time. It stands out due to its high safety level, storage stability and fast reaction time. The redox flow battery is suitable for the most diverse areas of application:

  • for the storage of solar-generated electricity,
  • as an emergency power supply, so that sensitive production systems and machine tools, for example, can continue to run in the event of a power cut,
  • to store electricity from wind power and biogas plants,
  • as a stand-alone solution wherever there is no stable electricity grid,
  • to supply power to compensate at peak times / heavy demand.


The advantages of the redox flow battery are:

  • its long lifetime,
  • an unlimited number of cycles of charging and discharging
  • a reaction time of less than 100 milliseconds,
  • extreme resistance to deep discharge,
  • only 1% energy loss per year,
  • the output and storage capacity are scaleable independently of each other,
  • low maintenance,
  • high environmental soundness.


The vanadium redox flow battery from Cellstrom will be presented by a+f from 9 to 11 June 2010 at the most important solar trade fair worlwide, the Intersolar in Munich.

a+f is thus expanding its division of renewable energy sources. The latest figures for the first quarter will be published by GILDEMEISTER on 4 May 2010 – due to its increasing importance for the first time in a separate segmental report for solar technology.

GILDEMEISTER Aktiengesellschaft
The Executive Board

Disclaimer, Forward-looking statement

Disclaimer, Forward-looking statement

Statements relating to the future:

This press release contains forward-looking statements, which are based on current estimates of the management of future developments. Such statements are based on the management's current expectations and specific assumptions. They are subject to risks, uncertainties and other factors, which could lead to the actual future circumstances, including the assets, liabilities, financial position and profit or loss of GILDEMEISTER, differing materially from or being more negative than those expressly or implicitly assumed or described in these statements. The business activities of GILDEMEISTER are subject to a series of risks and uncertainties, which may result in forward-looking statements, estimates or forecasts becoming inaccurate. Should one of these factors of uncertainty or other unforeseeable event occur, or should the assumptions on which these statements are based prove incorrect, the actual results may differ materially from the results stated, expected, anticipated, intended, planned, aimed at, estimated or projected in these statements. Forward-looking statements must not be understood as a guarantee or assurance of the future developments or events contained therein.