In Germany, there was an auction of the energy storage projects. The German regulator body, the Bundesnetzagentur, offered 250 MW of power. Sorry to say the auction was not successful, because only 155 MW was assigned after all.
The technical requirement is that in addition to the direct production from the renewable source (typically solar panels), the project needs to be able to provide a 2-hour energy supply from the battery power pack. All energy of the battery pack must be supplied from a renewable power source (typically solar) and cannot be used for re-storage of the energy the from grid.
Interestingly the auction price of the projects was from 39.90EUR/MWh to 54.80EUR/MWh, with the average of 45.50EUR/MWh. This price is a BONUS premium that the operators of the project will receive in addition to the market price they will get from the sales to the grid operators.
What do you think? Is 45.50EUR/MWh enough to run sustainable energy storage projects?