“We are combining for the first time a battery with a large-scale generation plant,” said Ralf Klein, managing director of the joint venture. “You can make money with that.”
The battery is small, with a maximum performance of just 5 MW. The Heilbronn site’s most modern unit has 750 MW of electric capacity and 550 MW heat.
However, it can absorb and release one fifth of the volume a big power plant normally releases into the balancing market at advantageous costs, because it can use existing staff, operations and grid access, Klein said.
The balancing market is vital to overcoming the intermittency inherent in renewable energy, which dominates the German power market. Batteries help stabilise grid swings within seconds.