| Vendor | Technology Category | Technology Type | Description / Notes | Status | ESTD Link |
|---|
| 1414 Degrees (website) | Thermal | Phase Change Material | TES systems using a silicon-based metallic phase change material (PCM) as the TES medium. | active | Published |
| 247 Solar (website) | Thermal | Ceramic | High-T air turbine fed by heat exchanger. Can also burn fuel. Or it's a supercapacitor. | active | |
| Active Power (website) | Mechanical | Flywheel | Designs and manufacturers flywheels | active | |
| Adena Power (website) | Electrochemical | Sodium Ion | Moderate Temperature | active | Published |
| Advance Rail Energy Storage (ARES) (website) | Mechanical | Gravity | Santa Barbara, CA based company developing a “mass and gravity” system using electric railcars and a sloped track | active | Published |
| Advanced Battery Concepts (website) | Electrochemical | Lead Acid | Advanced lead acid | active | |
| Aesir Technologies (website) | Electrochemical | Nickel Zinc | Targeting high power applications | active | |
| Aestus Energy Storage (website) | Thermal | Ceramic | Pittsford, NY based company developing a compact, advanced ceramic energy storage (ACES) system using a ceramic thermal storage medium, two turbomachinery trains, and an inert gas working fluid. | active | Published |
| Airlight Energy | Mechanical | Compressed Air | | dormant | |
| Airthium (website) | Thermal | Heat Pump | Airthium Seasonal Energy Storage uses a near-isothermal Stirling engine technology for power generation using mountains as the pressure chamber | active | Published |
| ALACAES (website) | Mechanical | Compressed Air | Swiss company developing an adiabatic compressed air energy storage using mountain caverns | dormant | |
| Alstom | Mechanical | Compressed Air | Back in early 2000s, not sure if anything was ever built, just designed | | |
| Altiro (website) | Thermochemical | Metal Oxide | | active | |
| Alumina Energy | Thermal | Ceramic | | active | Published |
| Amber Kinetics | Mechanical | Flywheel | | | Published |
| Ambri (website) | Electrochemical | Liquid Metal | | active | Published |
| America Clean Energy Group (website) | Electrical | Supercapacitor | | active | |
| Amogy | Chemical | Ammonia Production | | | |
| Amplified Pumped Storage (AMPS) (website) | Mechanical | Pumped Storage Hydro | Black and Veatch, Cykyl Systems, RockRiseES | active | |
| Ansaldo Energia (website) | Chemical | Hydrogen | gas turbine | | |
| Antora Energy (website) | Thermal | Graphite | Heat stored in solid carbon blocks. Developing thermophotovoltaic system for energy extraction | active | Published |
| Apex Compressed Air | Mechanical | Compressed Air | Salt dome | | Published |
| Aquanamic | Mechanical | Pumped Storage Hydro | Water is pumped into underground balloon, out again by weight of soil | active | Published |
| Augwind AirBattery | Mechanical | Compressed Air | storage tanks | active | Published |
| Avanti (website) | Electrochemical | Liquid Metal | Al-S | active | |
| Azelio | Thermal | Aluminum Alloy | | dormant | Published |
| Basquevolt (website) | Electrochemical | Lithium Ion | Solid state | active | |
| Batteryloop (website) | Electrochemical | Lithium Ion | Second-life | active | |
| Beacon | Mechanical | Flywheel | | | Published |
| Bechtel (website) | | | Working with Malta. Also doing some PSH | | |
| BgtL, Inc. | Thermal | Phase Change Material | | | Published |
| Bloom Energy (website) | Chemical | Hydrogen | blue hydrogen | | |
| BMW | Chemical | Hydrogen | liquid | | |
| BNE | Mechanical | Flywheel | | | |
| Brayton Energy (website) | Thermal | Pumped Thermal | reversible compressor-turbine | active | |
| Breeze (website) | Mechanical | Compressed Air | | active | Published |
| Brenmiller Energy | Thermal | Solid Materials | | active | Published |
| Bucky Battery (website) | Thermochemical | metal hydride | | | |
| BuildToZero (website) | Thermal | Phase Change Material | Molten salts | | |
| Cache Energy (website) | Thermochemical | Salt Hydrates | | active | Published |
| Cadenza Innovation, Inc. (website) | Electrochemical | Lithium Ion | Thermal runaway propagation prevention | active | Published |
| Caldera (website) | Thermal | Solid Materials | 500 C max. Recycled aluminum and volcanic rocks… | active | |
| Calmac (website) | Thermal | Ice Creation | Heat pumps | active | |
| Calnetix Technologies (website) | Mechanical | Flywheel | | | |
| CarbeniumTec (website) | Electrochemical | Flow | Organic | active | Published |
| Cavern Energy (website) | Mechanical | Pumped Storage Hydro | using salt caverns for underground PSH | | |
| CCT Energy Storage | Thermal | Phase Change Material | | | |
| Cellcius (website) | Thermochemical | Potassium Carbonate | Residential-scale heating with potassium salts that consume CO2 in production. Pilots in progress. | active | |
| Ceres Power | Chemical | Hydrogen | fuel cell | | |
| Cheesecake Energy (website) | Mechanical | Compressed Air | TES included | | |