The Tehachapi Wind Energy Storage Project will be located at Southern California Edison’s (SCE) Monolith Substation in Tehachapi, California and the 8MW x 4 hr (32MWh) BESS and 2 x 4MW/4.5MVA smart inverters will be housed in a 6,300 square foot facility. The project will evaluate the performance of the BESS to improve grid performance and assist in the integration of large-scale variable energy resourced generation. Project performance will be measured by 13 specific operational uses: providing voltage support and grid stabilization; decreasing transmission losses; diminishing congestion; increasing system reliability; deferring transmission investment; optimizing renewable-related transmission; providing system capacity and resources adequacy; integrating renewable energy (smoothing); shifting wind generation output; frequency regulation; spin/non-spin replacement reserves; ramp management; and energy price arbitrage. Most of the operations either shift other generation resources to meet peak load and other electricity system needs with stored electricity, or resolve grid stability and capacity concerns that result from the interconnection of variable energy resources. SCE will also demonstrate the ability of lithium-ion battery storage to provide nearly instantaneous maximum capacity for supply-side ramp rate control to minimize the need for fossil fuel-powered back-up generation.