Tesla Megapack

On April 30, 2015, Tesla announced that it would sell standalone battery storage products to consumers and utilities. Prior to the Megapack launch, Tesla used its 200 kilowatt-hour (kWh) Powerpack energy storage product to meet the needs of utilities with large-scale storage requirements such as at the Hornsdale Power Reserve. Design work began on the Megapack project at Giga Nevada at least as early as the first half of 2018. In July 2019, Megapack launched. Tesla acquired a former JCPenney distribution center in Lathrop, California, in 2021 and converted it into a battery plant called Megafactory, with a target capacity of 40 GWh/year when finished. Next-generation Megapacks use prismatic (rectangular) lithium iron phosphate (LFP) battery cells, for example in the 585 MWh Kapolei, Hawaii facility from 2024. Tesla's LFP cell suppliers include China's CATL and LG Energy Solution which has factories in South Korea and the US. Tesla's energy deployment added 3.9 GWh in the first quarter of 2023. The combined delivery of storage (Powerwall and Megapack) was 6.5 GWh in 2022, 14.7 GWh in 2023, and 31.4 GWh in 2024. In 2023, Tesla announced a new "Megafactory" in Shanghai to manufacture Megapacks, with the goal of producing about 10,000 packs per year, and the factory started low rate initial production in late 2024. Tesla builds a service facility at the 877 MWh Collie battery in Western Australia, to repair and remanufacture batteries in the state. On September 8 2025, the company announced a new product for late 2026, called "Megablock", which consists in up to 4 Megapacks version 3 connected with a transformer and a switchgear. Each Megapack 3 is 5 MWh (and 39 tonnes), so each Megablock is 20 MWh. They will be produced in Tesla new facility in Houston, Texas, using LG cells. == Specifications ==

Each Megapack comes with a 15-year "no defect" and "energy retention" warranty. Megapacks are pre-assembled, including "battery modules, bi-directional inverters, a thermal management system, an AC main breaker and controls." Tesla requires customers to purchase a maintenance service agreement. Each Megapack receives a minor annual service, and a major service every ten years. The annual maintenance includes inspections and cleaning. The ten-year maintenance includes activities such as replacing the pump and fan for the thermal management system and refilling the coolant fluid. Maintenance is expected to take about an hour per Megapack. == Design ==

The Megapack thermal management system is located at the top of each unit. It uses coolant fluid, made of an equal-parts mixture of ethylene glycol and water, to keep the battery at operating temperature. Each Megapack 2XL weighs approximately and the enclosure is built to a similar size as an intermodal container and includes twistlock fittings to allow automated handling. == Applications ==

3D sketch Grid batteries are used for ancillary services such as control of frequency and phase, black start, operating reserve etc. Peak power Megapacks are designed for large-scale energy storage. Megapacks are used by utilities to replace or augment peaker power plants, which generate energy during periods of peak demand. Megapacks store grid energy rather than generating it from fuel. Time shifting In some areas, energy storage has become a requirement to help convert intermittent energy sources such as wind and solar into firm power. Other energy storage solutions, such as pumped hydroelectric storage, dominate the time-shift market. As of 2019, pumped hydroelectric storage accounted for 96% of global energy storage capacity. Pumped hydroelectric storage systems have lower efficiency, but longer lifetimes than battery storage. Supercharger stations station with solar canopies and 8 Megapack set for close to 32 MWh Megapacks have been installed at Tesla Supercharger stations that also have solar canopies to help power the Megapacks. Megapacks can smooth out electric demand on the local power grid and use the stored Megapacks electricity during peak demand so there are not excessive surcharges on electricity to charge the electric vehicles. To support summer travel Tesla claimed in July 2025 to have connected for the first time a mobile Megapack to a European Supercharger, the Otočac station in Croatia. == Deployments ==

Completed In November 2019, Tesla used a Megapack to power a mobile recharging station for Tesla electric vehicles in California. In December 2019, Tesla delivered a 1.25 MW/2.5 MWh Megapack to the Millidgeville Substation in Saint John, Canada for peak shaving. The battery is estimated to save owner Saint John Energy CA$200,000 per year. It became operational on April 3, 2020. The 300 MW/450 MWh Victorian Big Battery near Geelong, Australia, constituted the largest battery in the southern hemisphere at the time. The commissioning process was halted due to a fire (see "Safety" section), and the lessons learned were applied to other batteries. The battery was commissioned on time in December 2021, a year after contract, with an estimated return on investment of 2.4. In December 2021, Strata Solar, an American commercial solar services provider, deployed a 100 MW/400 MWh energy storage facility in Ventura County, California, using 142 Megapacks. The deployment replaced a natural-gas peaker plant. 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. TransAlta owns and operates a 10 MW/20 MWh Megapack system near Pincher Creek, Alberta, Canada, which was completed in October 2020. As of July 2024, it is one of ten active storage sites in Alberta, and all are Megapacks. == Safety ==

Grid-scale battery standards and fire containment practices are at an early stage of development. Fire risks are one factor that has delayed the deployment of some utility energy storage systems. Most battery fires cannot be extinguished with water, which is the primary firefighting technique in most communities. A fire in a single cell can cascade to others via thermal runaway, possibly in milliseconds, potentially creating a major hazard. Vistra's third installation in Moss Landing adopted the outdoor container model instead of putting the racks under a single roof. (Vistra stated that the outdoor design was chosen to expedite construction.) In July 2021, one of the 212 Megapack modules at the Victorian Big Battery project caught fire due to a coolant leak while the battery was unmonitored. That ignited the adjacent Megapack. The alternating current section caught fire in September 2023 and spread to the cells of one Megapack module, also damaging the adjacent module. Both modules are being replaced by Tesla. Other 36 modules were operational a couple of days later. == See also ==