Executive Summary

The storage capacity currently connected to the network of the grid operators is almost totally composed of pumped hydro energy storage (PHES) plants (33GW). In most cases, the capacity related to battery energy storage systems (BESS) is still negligible (4GW).

Storage systems account for a few percentage points of the total generation capacity connected to networks (0.5 to 7%).
Most grid operators agree that storage technologies will play an important role within their network in the next years, as they have the potential to foster and support the non-programmable renewable sources integration into the grid.

New storage installations are expected to mainly consist of Li-Ion battery storage.

Storage systems are expected to provide real time balancing services and intraday, at least, energy shift.

The deployment of battery storages and the provision of ancillary services by them, although promising, is at its beginning stage in several areas of the world, thus it needs further studies
In this context, grid operators have shown interest in investigating the role that battery storage will play in the network over the coming years