German scientists test lithium ion and lead batteries in large-scale ESS


Scientists at the RWTH University of Aachen in Germany in September announced they had started testing a large-scale M5BAT battery storage system that uses five different chemistries — four lithium ion variants and lead acid.
The aim of the project is to test the usage possibilities of a combination of battery technologies in the grid and on the market.
With €6.7 million ($7.6 million) from the Energy Storage Funding Initiative of the German Federal Ministry for Economic Affairs and Energy, the project was directed by Dirk Uwe Sauer at the Institute of Power Generation and Storage Systems. It went into operation next to a transformer and the university’s research centres.
Exide Technologies provided the lead acid strings. Rainer Bußar, director of Industrial Batteries/R&D Europe at Exide Technologies, said: “In stationary applications, where size and weight matter less than they do in mobile applications, lead batteries represent an interesting technological alternative to finite lithium resources. Two of the five M5BAT lead battery strings will undergo direct technology comparison tests in the field.”
Project director Dirk Uwe Sauer said: “From day one, we have intensely and individually monitored more than 25,000 battery cells in six strings of different lithium-ion battery technologies and four strings of different lead batteries.
“This will allow us to gather valuable information on aging, reliability and service life. At the same time, we want to use intelligent battery management to show how overall operations can be optimized with a hybrid system using different technologies.”
The fully-automated operations will be monitored and operated with a remote control system from power generator Uniper SE, an offshoot from Germany utility Eon which is already using the system for energy trading.
Uniper chief operating officer Eckhardt Rümmler said: “M5BAT will allow us to test the possibility of using a combination of different battery technologies in a real network and on the market.
“This storage system has already been incorporated into Uniper’s trading business, and will soon deliver important findings regarding the development of business models based on decentralized storage systems. Energy storage systems are important if energy transformation is to be a success. They contribute greater flexibility and stability to energy systems. They are thus essential for a low-carbon energy supply based on renewable energies.”
Rik W De Doncker, director of the Sustainable Energy Cluster at RWTH Aachen University, said: “Now that operation has started, we expect interesting new findings regarding the economic and technical characteristics of battery storage systems. We plan to use these research results to improve economic feasibility and, so, effectively promote the introduction of battery storage systems onto the market.”
SMA Solar Technology made the inverters.