Initial stationary-storage product Tesla pilots at SolarCity homes — repurposed Roadster battery packs in residential applications, the proof-of-concept for what would become Powerwall. Anticipates a separate-business storage opportunity 5 years before formal Tesla Energy launch.

Powerwall 1 (10 kWh, then 6.4 kWh DC-coupled by 2016) and Powerpack (100 kWh) launched at Hawthorne, California event by Elon Musk on Apr 30 2015 — formal birth of Tesla Energy as a distinct business unit. Powerwall list price $3,000 / $3,500; Powerpack $25,000. Demand vastly outstripped supply: pre-orders booked through 2016 within first week.

Powerwall 2 unveiled — 14 kWh usable, integrated 5 kW inverter, AC-coupled architecture, $5,500 starting price (vs $3,500 PW1 + inverter). 2x energy density at lower $/kWh. Drives 5x demand uplift versus PW1; backlog crosses 500k pre-orders by 2018.

Hornsdale Power Reserve in South Australia (100 MW / 129 MWh) energised — world's largest Li-ion battery at the time, deployed in Elon Musk's famous "100 days or it's free" public bet with Mike Cannon-Brookes. Cycled within first weeks to stabilise national grid frequency events; saved AEMO ~A$150M in FCAS costs in first 24 months. The most influential utility-scale battery project ever — proves grid-storage market viability and unlocks subsequent multi-GWh project pipeline.

Megapack utility-scale product launched — 3 MWh per unit (later expanded to 3.9 MWh with XL variant) with integrated inverter and thermal management. Pre-engineered, factory-assembled approach drastically reduces deployment timelines from 12-18 months to 3-6 months. Drives Tesla Energy revenue inflection: $1.5B 2019 to $10B+ run rate by 2024.

Battery Day at Fremont: 4680 cell architecture announced with tabless ("shingle spiral") design, dry-electrode coating, silicon anode roadmap. Promised: 5x energy/cell, 6x power, 16% range improvement, 14% $/kWh reduction. Format becomes industry-defining target for 2022-2025; LG, Panasonic, Samsung SDI, EVE Energy, and BAK all spin up 4680 lines in response. Tesla 4680 ramp itself slower than promised — only ~30% of Model Y mix by end of 2024.

First 4680 cell production line ramped at Kato Road pilot facility, California — 100 cells/day initial output expanding to 1,000/day by end of Q1. Cells installed in Model Y vehicles produced at Texas Gigafactory; deliveries begin April 2022. Dry-electrode cathode coating remains the bottleneck for full ramp through 2024.

Inflation Reduction Act signed Aug 16 2022 — Megapack and 4680 cell production qualified for 45X manufacturing credits ($35/kWh cell + $10/kWh module). Estimated 2024 Tesla Energy cumulative IRA windfall: ~$2-2.5B; transforms Megapack gross margins from ~10% to >25%.

Lathrop Megafactory opened in California — initial 40 GWh/yr Megapack capacity (10,000 Megapacks/yr). First dedicated stationary-storage gigafactory in the US; supplies Megapack 2 and Megapack XL (3.9 MWh) units globally before Shanghai Megafactory comes online 2025.

Megapack 2 XL announced (3.9 MWh per unit, 30% larger than Megapack 2) and Shanghai Megafactory groundbreaking — 40 GWh/yr capacity for international markets, 10,000 Megapacks/yr. Tesla's first non-US gigafactory dedicated to stationary storage; production starts Feb 2025.

Powerwall 3 launched — 13.5 kWh with integrated solar inverter (11.5 kW continuous) and built-in solar MPPTs. ~30% lower $/kWh installed than PW2 with inverter. Drives 2024 Tesla Energy residential Powerwall deployments to >100k units.

Deployed 31.4 GWh of energy storage in 2024 — more than tripled 2022 levels (6.5 GWh) and almost doubled 2023 (14.7 GWh). Tesla Energy reaches ~$10B annualised revenue run-rate at >25% gross margin (with IRA credits). Now Tesla's fastest-growing segment by relative growth.

Shanghai Megafactory began producing Megapacks for international markets — initial 40 GWh/yr ramp, supplying European, Australian, Middle East ESS integrators. Hedges against US-China tariff escalation; Tesla's first non-US storage gigafactory at scale.