Energy storage is an essential part of a renewable-powered world. Storage averages out uneven rates of renewable supply or energy demand. Despite huge projected global demand in coming years, no practical energy storage method exists.
Until now. Special reversible cryogenic AVS engine/refrigerator combo units can store and recover energy as liquefied and frozen air in insulated tanks.
Air, the ultimate ubiquitous resource, can store energy by cooling, liquefying and freezing as a cryogenic refrigerator pumps heat away, and can then release that energy by melting, boiling and warming up as a cryogenic engine dumps heat back in. Thanks to the efficiency cycles and unique operational flexibility of AVS, the refrigerator and engine is actually one reversible machine that operates in two modes, able to switch instantly.
AVS energy storage should achieve total storage densities of 200 to 250 watt-hours per kilogram with round-trip efficiencies greater than 90%, matching the best lithium-ion battery densities but with no loss of storage capacity over time.
AVS energy storage has substantial cost advantages over lithium-ion batteries:
- raw materials are commonly available
- all system components have dual functions for minimum complexity
- system consists only of engine/refrigerator with motor/generator, insulated tank and heat exchanger
- operational lifespan can be much longer
- AVS machines can turn at 3,600 RPM for connection to 60 Hz AC systems without expensive inverters.
Space