Tehachapi is nominally a wind energy-related project attached to the 4.5 GW Tehachapi Wind Resource Area, although in actual fact the plant was conceived as a two-year test bed for a wide range of potential grid applications. When it opened, in September 2014, it was credited with being the largest battery storage project in the North of the US, with 604,832 Li-ion cells housed in 10,872 modules.
Everyone knows California and New York do have behind-the-meter energy storage at a large scale. But there are some sleeper states where the economics already work.