Megapack, Mega Power: Tesla Battery Storage Adds 800 MWh to Grid

A 200 MW/800 MWh battery storage system has started delivering electricity to the grid in Grand Terrace, California. 

Watch a Tesla Megapack installation in California. Video used courtesy of Tesla

The Condor Energy Storage Project, headed by Arizona-based renewable developer Arevon, features several rows of Tesla Megapack 2 XL lithium-ion batteries. During peak demand periods, each container can provide up to four hours of stored energy to 150,000 homes. 

The project comes online amid a surge in battery storage capacity joining California’s grid, bringing a valuable asset to help operators manage the summer’s triple-digit heat waves. 

Arevon’s Condor Energy Storage Project in San Bernardino County, California. Image used courtesy of Arevon

Tesla’s Megapack 2 XL Battery Storage System

Arevon selected Tesla’s increasingly popular Megapack 2 XL battery energy storage system (BESS) for the Condor project. Tesla is facing high demand for the utility-scale system, necessitating a second Megapack factory currently under construction in China. Its first facility in California can produce 10,000 units annually, roughly equivalent to 40 GWh of deployments. 

Megapack 2 XL releases stored energy into the grid when solar and wind resources are unavailable to meet peak demand. The four-hour configuration offers 1 MW of power and 3.9 MWh of energy storage per unit, with a 93.7% round-trip efficiency. 

The 84,000-pound lithium-ion battery containers are about 28 feet wide and 10 feet tall and comprise several battery modules, controls, an integrated inverter, and a thermal management system. The modular design allows flexibility for various projects, including standalone and solar-plus-storage configurations. 

Condor’s construction spanned 280,000 work hours, including building a new power transformer, control equipment, and an interconnection tower linking to a nearby substation. Arevon tapped Tesla to provide continued operations and maintenance for the project. 

 A rendering of the Condor Energy Storage Project. Image used courtesy of Arevon

Southern California Edison (SCE) signed a 15-year agreement to purchase new capacity from Condor. This will help the utility manage volatility from the growing share of renewable energy on its grid, accounting for 52% of last year’s electricity sales. SCE’s energy storage portfolio is among the nation’s largest, with about 7.2 GW installed or contracted. It also interconnected over 16,600 storage and solar-paired systems last year. 

Battery Storage Deployment Grows

A recent spike in commissioning activities brought California’s total battery capacity to 10.3 GW earlier this year. This influx helped the California Independent System Operator (CAISO) maintain smooth operations during July’s two-week heat wave. Batteries now represent a significant share of CAISO’s loads during peak solar hours. 

Condor is Arevon’s third utility-scale storage system in California. The company has nearly 2.5 GW of operational renewable energy projects statewide; another 1.2 GW is under construction. It recently signed offtake agreements with utilities for two upcoming projects: Cormorant Energy Storage, a 250 MW/1 GWh standalone BESS starting construction next year, and Avocet, a 200 MW/800 MWh standalone BESS scheduled to come online in mid-2026. 

Tesla Megapack containers line the Condor Energy Storage Project. Image used courtesy of Arevon

Arevon also has a few hybrid projects underway in California. Eland 2 Solar-Plus-Storage is expected to come online in early 2025, with 374 MW of solar power and 150 MW/600 MWh of storage from Megapack 2 XL units. Later this year, it will begin operating Vikings Solar-Plus-Storage, a large-scale solar peaker plant featuring 157 MW worth of First Solar modules and 150 MW/600 MWh of storage from Megapack batteries.