Technology costs for battery storage continue to drop quickly, largely owing to the rapid scale-up of battery manufacturing for electric vehicles, stimulating deployment in the power sector.

Storage is one of a suite of options to provide energy system flexibility, and it can generally be deployed quickly and modularly when and where flexibility is needed.

Its attractiveness should still be assessed relative to other measures, however, such as demand response, power plant retrofits, smart-grid measures that enhance electricity networks, and other options that raise overall flexibility.

Direct support for storage through mandates and policies remains the most common option to incentivise deployment, but greater emphasis should be placed on making regulations transparent and open, and on developing markets for capacity, flexibility and ancillary services so that storage can compete with other technologies and measures.

[Source : International Energy Agency - Last updated Sep 14, 2020]
[https://www.iea.org/fuels-and-technologies/energy-storage]