The batteries would also need to have at least 1,000, and preferably 1,500 charge - discharge cycles without showing a noticeable power or energy storage capacity loss. (sciencedaily.com)
Currently, the grid has very little energy storage capacity, so any energy generated must be immediately consumed. (blog.aurorasolar.com)
Implying the use of hydro storage, it states that «in particular, increased use of energy storage capacity in Southern Germany, the Alpine countries and possibly in Scandinavia means that the grid infrastructure must be expanded.» (renewableenergyworld.com)