Storage is used in just about every industry that operates. In all aspects of commerce, storage is used throughout the value chain to balance supply and demand and to buffer the upstream supply from the fluctuations in downstream demand. Electricity storage is unique in the ease with which the technologies can be scaled. When a storage facility is colocated at a generation facility for provision of ancillary services, time arbitrage, or renewable firming, it has little additional impact on the grid or the substation—indeed usually it would act to reduce variability and is probably a positive factor in terms of the substation itself. As with generation area applications, a significant benefit that storage can bring to the transmission system is shifting the energy commodity in time and location. A storage system at a wind farm can help avoid curtailment due to transmission congestion—when the wind farm production in excess of local load exceeds the transmission path’s available capacity.