Energy storage can contribute to the smart grid by facilitating integration of renewable sources and provision of important ancillary services. At the same time, energy storage cannot really be exploited to its fullest potential without a smart grid infrastructure capable of managing bidirectional energy flows. Because of that reciprocal relationship, energy storage and the smart grid represent an indispensable synergy.
It is generally appreciated that electrical energy storage systems can greatly enhance the efficiency and usefulness of intermittent energy sources, such as solar and wind energy, whether or not turbines and solar panels are on or off the grid. Equally important, but perhaps less widely recognized, storage can also be leveraged to furnish ancillary services for the distribution grid, such as frequency regulation, spinning reserves and voltage control—services that will be needed more crucially than ever as the smart grid becomes a widespread reality.