Germany misses out on large-scale batteries' potential to stabilise grid – report
Clean Energy Wire
Large-scale batteries already take and provide electricity in a way that helps stabilise Germany’s grids without causing additional costs, but their contribution could be much higher, according to a report by consultancy Neon.
“Our calculations show that a large-scale battery relieves and burdens the grid with approximately equal frequency,” the authors wrote. However, their contribution “falls well short of its potential,” they added, pointing out that “large-scale batteries should by no means be classified as a burden on the grid”.
The report’s authors analysed the charge, discharge and idle behaviour of two large-scale batteries: one in the northern state of Schleswig-Holstein and a theoretical one in southern Bavaria. They then calculated whether their behaviour affected redispatch and grid expansion costs. “From a financial perspective, the battery reduces redispatch costs over the course of the year, even if the contribution is small,” they concluded.
Grid-related price signals could increase the effect, as the grid-friendly behaviour is purely coincidental, the authors found. Germany’s electricity market has a single power price zone, where electricity is traded for the entire country. Large-scale batteries use market signals to buy electricity and charge up when prices are low, and feed electricity back into the grid when prices are higher.
Because electricity can be traded throughout Germany, grid bottlenecks are not visible. However, often electricity from the windy north cannot be transported to consumption centres in the south because grids are clogged up, causing costly so-called redispatch costs.
The authors therefore suggest the government introduce a special battery grid fee, which would set a variable price for withdrawing or feeding electricity every quarter-hour, depending on the regional capacity of grids to transport electricity.
“We want to get the most out of batteries because, after all, we believe they are essential for our energy future,” said Georg Gallmetzer, head of storage system developer ECO STOR, who commissioned the report. “This requires incentives that benefit the grid. If we can achieve this, everyone involved would benefit - storage operators, grid operators, consumers, and the economy.”
Battery storage systems are a key technology in a renewable energy system, providing flexibility, grid stability, and the ability to bridge periods of low power generation. There is high interest in bringing large-scale battery storage projects to life in Germany, though network operators have warned that this could pose difficulties for them. The renewable power industry recently criticised that Germany’s latest electricity security of supply monitoring report did not properly account for the potential of large-scale battery storage.
