Battery storage is essential to compensate for natural fluctuations in output from solar power plants and wind turbines, ensuring a stable electricity supply. Swedish electric utility Vattenfall is working with BMW and Bosch to test a system that uses second-life EV batteries for this purpose.

The companies operate a 2 MW, 2,800 kWh electricity storage facility in Hamburg, Germany, comprising 2,600 battery modules from more than 100 BMW EVs. Vattenfall sells the stored energy on the primary control reserve market, which requires power to be available within a few seconds to help maintain a constant grid frequency of 50 Hz.

The Battery 2nd Life development project began in 2013, and is planned to last for five years. The partners hope to learn more about the aging characteristics and storage capacity of used lithium-ion battery modules.

“Thanks to smart electronic controllers, these storage systems can absorb excess electricity and release it again very quickly when needed,” says Cordelia Thielitz, General Manager of Bosch Energy Storage Solutions. “We expect to gain valuable knowledge from the Battery 2nd Life development project, and we regard it is as an important step on the way to a more efficient and more decentralized energy system.”

“Our goal is to integrate this battery storage facility into the energy system and to give a large number of similar small local facilities access to the market through electricity trading,” said Vattenfall Executive Pieter Wasmuth.

“In future, with BMW Storage, we will be able to offer efficient battery storage solutions tailored to customer needs,” said BMW VP Dr. Bernhard Blättel. “In the context of the new energy landscape, the BMW Group regards energy storage as the core component of energy management.”

Source: Bosch via Green Car Congress