M5BAT Modular Utility-Scale Storage System to be Built in Aachen

The E.ON Energy Research Center at RWTH Aachen University, E.ON electric utility company, battery makers Exide Technologies GmbH and Beta Motion GmbH, and inverter maker SMA Solar Technology AG have joined forces to build the world's first, modular large-scale 5-megawatt battery storage system in Aachen this year. The M5BAT (Modular Multimegawatt, Multitechnology Medium-Voltage Battery Storage System) project is backed by a €6.5 million grant from the German Federal Ministry for Economic Affairs and Energy as part of its "Energy Storage Funding Initiative." The project will be coordinated by RWTH Aachen University.

The unique feature of the M5BAT storage system lies in its modular design, which combines different battery technologies for optimal use. It consists of lithium-ion batteries to meet short-term demand, high-temperature batteries to supply power for several hours, and lead-acid batteries when the average discharge time is one hour or less. Construction is scheduled to begin later this year, with the system entering service by 2015.

“The growth of renewables in Germany is making smart grids and large-scale energy storage technologies increasingly more important,” said Leonard Birnbaum, member of the E.ON Board of Management responsible for technology issues. “Since a number of years, E.ON, through its Technology and Innovation (T&I) activities, has been investing in a broad spectrum of technologies of the future. Battery storage systems are particularly interesting because, unlike compressed-air storage or pumped-storage hydro, they aren’t subject to narrow geographic constraints and don’t require long planning cycles.”

E.ON is responsible for planning and construction of the battery storage facility and for developing and testing marketing strategies for future storage products for the energy marketplace. The Institute of Power Systems and Power Economics (IAEW) at RWTH Aachen University will provide research support. The E.ON Energy Research Center at RWTH Aachen University will operate the system, integrate it into the grid, and provide scientific support. The manufacturers—Exide Technologies GmbH, beta-motion GmbH, and SMA Solar Technology AG—will supply the technical components and conduct operational testing.

This project will deploy Exide Technologies’ innovative VRLA gel and CSM copper plate technology, which delivers high cyclic application capacity and high-current discharge. Beta-motion GmbH’s high-output lithium ion batteries will be used for efficient load management. SMA’s highly flexible battery inverters give the system its scalability and modularity. Project Management Jülich (PTJ) will coordinate the public funding on behalf of the German Federal Ministry of Economic Affairs and Energy. Plans call for construction to begin in the fall of 2014 and for the utility-scale storage system to enter service in 2015.

Due to its power class and high level of modularity, the battery storage system will be the first of its kind in the world and opens up a wide array of potential applications. The first phase of the project will focus on the following areas: Integration of renewable energy sources and testing of a decentralized supply of control power to stabilize grid operation, and facilitating electricity trading at competitive prices.

“To achieve a 100 percent renewable power supply, adding large-scale storage systems to the utility grid is of vital importance. These systems back up the power from renewable sources and help stabilize utility grids. This research project will provide us with important data on how large-scale battery inverters can be used in the utility grid in the future. The goal is to develop a concept for modular and flexibly scalable battery inverter systems that can be used to supply all critical grid management services in the utility grid,” explained Volker Wachenfeld, Senior Vice President Hybrid & Storage at SMA.