[1] Tesla CEO Elon Musk stated that the company's battery storage products could be used to improve the reliability of intermittent renewable energy sources, such as solar and wind.

[3] Tesla acquired a former JC Penney's distribution center in Lathrop, California, in 2021 and converted it into a battery plant called Megafactory,[4] with a target capacity of 40 GWh/year when finished.

[5] Next-generation Megapacks use prismatic lithium iron phosphate cells,[6] for example in the 585 MWh Kapolei, Hawaii facility.

[9] In 2023, Tesla announced a new “Megafactory” in Shanghai to manufacture Megapacks, with the goal of producing about 10,000 packs per year,[10] and the factory started low rate initial production in late 2024.

[16] Megapacks are pre-assembled, including "battery modules, bi-directional inverters, a thermal management system, an AC main breaker and controls.

The ten-year maintenance includes activities such as replacing the pump and fan for the thermal management system and refilling the coolant fluid.

[16] It uses coolant fluid, made of an equal-parts mixture of ethylene glycol and water, to keep the battery at operating temperature.

[16] Each Megapack weighs approximately 51,000 pounds (23,000 kg) and the enclosure is built to a similar size as an intermodal container and includes twistlock fittings to allow automated handling.

Megapacks are used by utilities to replace peaker power plants,[20] which generate energy during periods of peak demand.

[27] The mobile Supercharger delivered 125 kW, and was transported on a flat trailer attached to a truck between deployment locations.

[27] In December 2019, Tesla delivered a 1.25 MW/2.5 MWh Megapack to the Millidgeville Substation in Saint John, Canada for peak shaving.

As of June 2022, Pacific Gas and Electric Company (PG&E) operates a 182.5 MW/730 MWh 256-Megapack system at Moss Landing, in Monterey County, California.

[38][39][3][40] TransAlta owns and operates a 10 MW/20 MWh Megapack system near Pincher Creek, Alberta, Canada, which was completed in October 2020.

A fire in a single cell can cascade to others via thermal runaway, possibly in milliseconds, potentially creating a major hazard.

A later plume analysis by Vistra reported that concentrations of HF above California exposure limits could spread across an area 1300 feet in diameter under wind conditions that occur 7 percent of the year.

Heat-suppression systems, intended to curb thermal runaway, were accidentally triggered, dousing batteries in water that caused arcing and short circuiting.

[44] Vistra's third installation in Moss Landing adopted the outdoor container model instead of putting the racks under a single roof.